2010-07-23 16:52:35 +00:00
|
|
|
#include "param.h"
|
|
|
|
|
#include "types.h"
|
|
|
|
|
#include "defs.h"
|
|
|
|
|
#include "x86.h"
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
#include "msr.h"
|
2011-07-29 11:31:27 +00:00
|
|
|
#include "memlayout.h"
|
2010-07-23 16:52:35 +00:00
|
|
|
#include "mmu.h"
|
|
|
|
|
#include "proc.h"
|
|
|
|
|
#include "elf.h"
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
#include "traps.h"
|
2010-07-23 16:52:35 +00:00
|
|
|
|
2011-09-02 18:51:55 +00:00
|
|
|
extern char data[]; // defined by kernel.ld
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
void sysentry(void);
|
|
|
|
|
|
|
|
|
|
static pde_t *kpml4; // kernel address space, used by scheduler and bootup
|
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|
|
|
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|
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|
// Bootstrap GDT. Used by boot.S but defined in C
|
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|
// Map "logical" addresses to virtual addresses using identity map.
|
|
|
|
|
// Cannot share a CODE descriptor for both kernel and user
|
|
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|
|
// because it would have to have DPL_USR, but the CPU forbids
|
|
|
|
|
// an interrupt from CPL=0 to DPL=3.
|
|
|
|
|
struct segdesc bootgdt[NSEGS] = {
|
|
|
|
|
[0] = SEGDESC(0, 0, 0), // null
|
|
|
|
|
[1] = SEGDESC(0, 0xfffff, SEG_R|SEG_CODE|SEG_S|SEG_DPL(0)|SEG_P|SEG_D|SEG_G), // 32-bit kernel code
|
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|
|
|
[2] = SEGDESC(0, 0, SEG_R|SEG_CODE|SEG_S|SEG_DPL(0)|SEG_P|SEG_L|SEG_G), // 64-bit kernel code
|
|
|
|
|
[3] = SEGDESC(0, 0xfffff, SEG_W|SEG_S|SEG_DPL(0)|SEG_P|SEG_D|SEG_G), // kernel data
|
|
|
|
|
// The order of the user data and user code segments is
|
|
|
|
|
// important for syscall instructions. See initseg.
|
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|
|
|
[6] = SEGDESC(0, 0xfffff, SEG_W|SEG_S|SEG_DPL(3)|SEG_P|SEG_D|SEG_G), // 64-bit user data
|
|
|
|
|
[7] = SEGDESC(0, 0, SEG_R|SEG_CODE|SEG_S|SEG_DPL(3)|SEG_P|SEG_L|SEG_G), // 64-bit user code
|
|
|
|
|
};
|
|
|
|
|
|
2010-07-23 16:52:35 +00:00
|
|
|
|
2010-09-02 20:23:15 +00:00
|
|
|
// Set up CPU's kernel segment descriptors.
|
2011-08-16 00:11:13 +00:00
|
|
|
// Run once on entry on each CPU.
|
2010-09-02 20:23:15 +00:00
|
|
|
void
|
2010-09-13 19:34:44 +00:00
|
|
|
seginit(void)
|
2010-09-02 20:23:15 +00:00
|
|
|
{
|
|
|
|
|
struct cpu *c;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
struct desctr dtr;
|
|
|
|
|
|
|
|
|
|
c = mycpu();
|
|
|
|
|
memmove(c->gdt, bootgdt, sizeof bootgdt);
|
|
|
|
|
dtr.limit = sizeof(c->gdt)-1;
|
|
|
|
|
dtr.base = (uint64) c->gdt;
|
|
|
|
|
lgdt((void *)&dtr.limit);
|
|
|
|
|
|
|
|
|
|
// When executing a syscall instruction the CPU sets the SS selector
|
|
|
|
|
// to (star >> 32) + 8 and the CS selector to (star >> 32).
|
|
|
|
|
// When executing a sysret instruction the CPU sets the SS selector
|
|
|
|
|
// to (star >> 48) + 8 and the CS selector to (star >> 48) + 16.
|
|
|
|
|
uint64 star = ((((uint64)UCSEG|0x3)- 16)<<48)|((uint64)(KCSEG)<<32);
|
|
|
|
|
writemsr(MSR_STAR, star);
|
|
|
|
|
writemsr(MSR_LSTAR, (uint64)&sysentry);
|
|
|
|
|
writemsr(MSR_SFMASK, FL_TF | FL_IF);
|
|
|
|
|
|
|
|
|
|
// Initialize cpu-local storage.
|
|
|
|
|
writegs(KDSEG);
|
|
|
|
|
writemsr(MSR_GS_BASE, (uint64)c);
|
|
|
|
|
writemsr(MSR_GS_KERNBASE, (uint64)c);
|
2010-09-02 20:23:15 +00:00
|
|
|
}
|
|
|
|
|
|
2010-09-02 20:36:38 +00:00
|
|
|
// Return the address of the PTE in page table pgdir
|
2011-08-16 00:21:14 +00:00
|
|
|
// that corresponds to virtual address va. If alloc!=0,
|
2010-08-05 16:10:54 +00:00
|
|
|
// create any required page table pages.
|
2010-07-23 16:52:35 +00:00
|
|
|
static pte_t *
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
walkpgdir(pde_t *pml4, const void *va, int alloc)
|
2010-07-23 16:52:35 +00:00
|
|
|
{
|
2018-10-02 11:37:49 +00:00
|
|
|
pde_t *pgtab = pml4;
|
2010-07-23 16:52:35 +00:00
|
|
|
pde_t *pde;
|
2018-10-02 11:37:49 +00:00
|
|
|
int level;
|
|
|
|
|
|
|
|
|
|
for (level = L_PML4; level > 0; level--) {
|
|
|
|
|
pde = &pgtab[PX(level, va)];
|
|
|
|
|
if(*pde & PTE_P)
|
|
|
|
|
pgtab = (pte_t*)P2V(PTE_ADDR(*pde));
|
|
|
|
|
else {
|
|
|
|
|
if(!alloc || (pgtab = (pte_t*)kalloc()) == 0)
|
|
|
|
|
return 0;
|
|
|
|
|
memset(pgtab, 0, PGSIZE);
|
|
|
|
|
*pde = V2P(pgtab) | PTE_P | PTE_W | PTE_U;
|
|
|
|
|
}
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
}
|
2010-07-23 16:52:35 +00:00
|
|
|
return &pgtab[PTX(va)];
|
|
|
|
|
}
|
|
|
|
|
|
2011-08-16 19:47:22 +00:00
|
|
|
// Create PTEs for virtual addresses starting at va that refer to
|
|
|
|
|
// physical addresses starting at pa. va and size might not
|
2010-08-05 20:00:59 +00:00
|
|
|
// be page-aligned.
|
2010-07-23 16:52:35 +00:00
|
|
|
static int
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
mappages(pde_t *pgdir, void *va, uint64 size, uint64 pa, int perm)
|
2010-07-23 16:52:35 +00:00
|
|
|
{
|
2011-01-11 18:01:13 +00:00
|
|
|
char *a, *last;
|
|
|
|
|
pte_t *pte;
|
2016-08-25 13:13:00 +00:00
|
|
|
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
a = (char*)PGROUNDDOWN((uint64)va);
|
|
|
|
|
last = (char*)PGROUNDDOWN(((uint64)va) + size - 1);
|
2011-01-11 18:01:13 +00:00
|
|
|
for(;;){
|
2011-09-13 17:14:52 +00:00
|
|
|
if((pte = walkpgdir(pgdir, a, 1)) == 0)
|
2011-01-11 18:01:13 +00:00
|
|
|
return -1;
|
2010-08-05 16:10:54 +00:00
|
|
|
if(*pte & PTE_P)
|
|
|
|
|
panic("remap");
|
2010-08-05 20:00:59 +00:00
|
|
|
*pte = pa | perm | PTE_P;
|
|
|
|
|
if(a == last)
|
|
|
|
|
break;
|
|
|
|
|
a += PGSIZE;
|
|
|
|
|
pa += PGSIZE;
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
2011-01-11 18:01:13 +00:00
|
|
|
return 0;
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
|
|
|
|
|
2011-09-13 16:28:45 +00:00
|
|
|
// There is one page table per process, plus one that's used when
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
// a CPU is not running any process (kpml4). The kernel uses the
|
2011-09-13 16:28:45 +00:00
|
|
|
// current process's page table during system calls and interrupts;
|
|
|
|
|
// page protection bits prevent user code from using the kernel's
|
|
|
|
|
// mappings.
|
2016-08-25 13:13:00 +00:00
|
|
|
//
|
2010-09-02 20:23:15 +00:00
|
|
|
// setupkvm() and exec() set up every page table like this:
|
2011-09-13 16:28:45 +00:00
|
|
|
//
|
|
|
|
|
// 0..KERNBASE: user memory (text+data+stack+heap), mapped to
|
|
|
|
|
// phys memory allocated by the kernel
|
2011-09-01 14:25:20 +00:00
|
|
|
// KERNBASE..KERNBASE+EXTMEM: mapped to 0..EXTMEM (for I/O space)
|
2011-09-13 16:28:45 +00:00
|
|
|
// KERNBASE+EXTMEM..data: mapped to EXTMEM..V2P(data)
|
|
|
|
|
// for the kernel's instructions and r/o data
|
2016-08-25 13:13:00 +00:00
|
|
|
// data..KERNBASE+PHYSTOP: mapped to V2P(data)..PHYSTOP,
|
2011-09-13 16:28:45 +00:00
|
|
|
// rw data + free physical memory
|
2011-09-01 14:25:20 +00:00
|
|
|
// 0xfe000000..0: mapped direct (devices such as ioapic)
|
2010-09-02 20:23:15 +00:00
|
|
|
//
|
2011-09-13 16:28:45 +00:00
|
|
|
// The kernel allocates physical memory for its heap and for user memory
|
|
|
|
|
// between V2P(end) and the end of physical memory (PHYSTOP)
|
|
|
|
|
// (directly addressable from end..P2V(PHYSTOP)).
|
|
|
|
|
|
|
|
|
|
// This table defines the kernel's mappings, which are present in
|
|
|
|
|
// every process's page table.
|
2011-02-20 02:17:55 +00:00
|
|
|
static struct kmap {
|
2011-08-16 00:21:14 +00:00
|
|
|
void *virt;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint64 phys_start;
|
|
|
|
|
uint64 phys_end;
|
2011-02-20 02:17:55 +00:00
|
|
|
int perm;
|
|
|
|
|
} kmap[] = {
|
2012-08-28 18:11:23 +00:00
|
|
|
{ (void*)KERNBASE, 0, EXTMEM, PTE_W}, // I/O space
|
|
|
|
|
{ (void*)KERNLINK, V2P(KERNLINK), V2P(data), 0}, // kern text+rodata
|
|
|
|
|
{ (void*)data, V2P(data), PHYSTOP, PTE_W}, // kern data+memory
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
{ (void*)P2V(DEVSPACE), DEVSPACE, DEVSPACETOP, PTE_W}, // more devices
|
2011-02-20 02:17:55 +00:00
|
|
|
};
|
2010-07-23 16:52:35 +00:00
|
|
|
|
2010-09-02 20:23:15 +00:00
|
|
|
// Set up kernel part of a page table.
|
|
|
|
|
pde_t*
|
2012-08-23 00:19:37 +00:00
|
|
|
setupkvm(void)
|
2010-09-02 20:23:15 +00:00
|
|
|
{
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
pde_t *pml4;
|
2011-02-20 02:17:55 +00:00
|
|
|
struct kmap *k;
|
2010-07-23 16:52:35 +00:00
|
|
|
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
if((pml4 = (pde_t*)kalloc()) == 0)
|
2010-09-02 20:23:15 +00:00
|
|
|
return 0;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
memset(pml4, 0, PGSIZE);
|
|
|
|
|
if (PHYSTOP > DEVSPACE)
|
2011-08-17 00:23:17 +00:00
|
|
|
panic("PHYSTOP too high");
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
for(k = kmap; k < &kmap[NELEM(kmap)]; k++) {
|
|
|
|
|
if(mappages(pml4, k->virt, k->phys_end - k->phys_start,
|
2017-02-05 10:44:56 +00:00
|
|
|
(uint)k->phys_start, k->perm) < 0) {
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
freevm(pml4, 0);
|
2011-02-20 02:17:55 +00:00
|
|
|
return 0;
|
2017-02-05 10:44:56 +00:00
|
|
|
}
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
}
|
|
|
|
|
return pml4;
|
2010-09-02 20:23:15 +00:00
|
|
|
}
|
2010-07-23 16:52:35 +00:00
|
|
|
|
2011-07-29 11:31:27 +00:00
|
|
|
// Allocate one page table for the machine for the kernel address
|
|
|
|
|
// space for scheduler processes.
|
|
|
|
|
void
|
|
|
|
|
kvmalloc(void)
|
|
|
|
|
{
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
kpml4 = setupkvm();
|
2011-07-29 11:31:27 +00:00
|
|
|
switchkvm();
|
|
|
|
|
}
|
|
|
|
|
|
2010-09-02 20:36:38 +00:00
|
|
|
// Switch h/w page table register to the kernel-only page table,
|
|
|
|
|
// for when no process is running.
|
2010-09-02 20:23:15 +00:00
|
|
|
void
|
2011-02-20 02:17:55 +00:00
|
|
|
switchkvm(void)
|
2010-09-02 20:23:15 +00:00
|
|
|
{
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
lcr3(V2P(kpml4)); // switch to the kernel page table
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
|
|
|
|
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
|
2011-02-20 02:17:55 +00:00
|
|
|
// Switch TSS and h/w page table to correspond to process p.
|
2010-07-23 16:52:35 +00:00
|
|
|
void
|
2010-08-06 15:12:18 +00:00
|
|
|
switchuvm(struct proc *p)
|
2010-07-23 16:52:35 +00:00
|
|
|
{
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
struct desctr dtr;
|
|
|
|
|
struct cpu *c;
|
|
|
|
|
|
2016-12-23 01:26:37 +00:00
|
|
|
if(p == 0)
|
|
|
|
|
panic("switchuvm: no process");
|
|
|
|
|
if(p->kstack == 0)
|
|
|
|
|
panic("switchuvm: no kstack");
|
|
|
|
|
if(p->pgdir == 0)
|
|
|
|
|
panic("switchuvm: no pgdir");
|
|
|
|
|
|
2010-07-23 16:52:35 +00:00
|
|
|
pushcli();
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
|
|
|
|
|
c = mycpu();
|
|
|
|
|
uint64 base = (uint64) &(c->ts);
|
|
|
|
|
c->gdt[TSSSEG>>3] = SEGDESC(base, (sizeof(c->ts)-1), SEG_P|SEG_TSS64A);
|
|
|
|
|
c->gdt[(TSSSEG>>3)+1] = SEGDESCHI(base);
|
|
|
|
|
c->ts.rsp[0] = (uint64) p->kstack + KSTACKSIZE;
|
|
|
|
|
c->ts.iomba = (ushort) 0xFFFF;
|
|
|
|
|
|
|
|
|
|
dtr.limit = sizeof(c->gdt) - 1;
|
|
|
|
|
dtr.base = (uint64)c->gdt;
|
|
|
|
|
lgdt((void *)&dtr.limit);
|
|
|
|
|
|
|
|
|
|
ltr(TSSSEG);
|
|
|
|
|
|
2016-08-24 17:40:06 +00:00
|
|
|
lcr3(V2P(p->pgdir)); // switch to process's address space
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
|
2010-07-23 16:52:35 +00:00
|
|
|
popcli();
|
|
|
|
|
}
|
|
|
|
|
|
2010-09-02 20:39:55 +00:00
|
|
|
// Load the initcode into address 0 of pgdir.
|
|
|
|
|
// sz must be less than a page.
|
2010-09-02 20:23:15 +00:00
|
|
|
void
|
|
|
|
|
inituvm(pde_t *pgdir, char *init, uint sz)
|
|
|
|
|
{
|
2011-01-11 18:01:13 +00:00
|
|
|
char *mem;
|
2016-08-25 13:13:00 +00:00
|
|
|
|
2011-01-11 18:01:13 +00:00
|
|
|
if(sz >= PGSIZE)
|
2010-09-02 20:23:15 +00:00
|
|
|
panic("inituvm: more than a page");
|
2011-01-11 18:01:13 +00:00
|
|
|
mem = kalloc();
|
2010-09-02 20:23:15 +00:00
|
|
|
memset(mem, 0, PGSIZE);
|
2016-08-24 17:40:06 +00:00
|
|
|
mappages(pgdir, 0, PGSIZE, V2P(mem), PTE_W|PTE_U);
|
2010-09-02 20:23:15 +00:00
|
|
|
memmove(mem, init, sz);
|
|
|
|
|
}
|
|
|
|
|
|
2010-09-02 20:39:55 +00:00
|
|
|
// Load a program segment into pgdir. addr must be page-aligned
|
|
|
|
|
// and the pages from addr to addr+sz must already be mapped.
|
2010-09-02 20:23:15 +00:00
|
|
|
int
|
|
|
|
|
loaduvm(pde_t *pgdir, char *addr, struct inode *ip, uint offset, uint sz)
|
|
|
|
|
{
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint i, n;
|
|
|
|
|
uint64 pa;
|
2010-09-02 20:23:15 +00:00
|
|
|
pte_t *pte;
|
|
|
|
|
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
if((uint64) addr % PGSIZE != 0)
|
2011-02-20 02:17:55 +00:00
|
|
|
panic("loaduvm: addr must be page aligned");
|
2010-09-02 20:23:15 +00:00
|
|
|
for(i = 0; i < sz; i += PGSIZE){
|
2011-08-10 01:56:43 +00:00
|
|
|
if((pte = walkpgdir(pgdir, addr+i, 0)) == 0)
|
2011-02-20 02:17:55 +00:00
|
|
|
panic("loaduvm: address should exist");
|
2010-09-02 20:23:15 +00:00
|
|
|
pa = PTE_ADDR(*pte);
|
2011-01-11 18:01:13 +00:00
|
|
|
if(sz - i < PGSIZE)
|
|
|
|
|
n = sz - i;
|
|
|
|
|
else
|
|
|
|
|
n = PGSIZE;
|
2016-08-24 17:40:06 +00:00
|
|
|
if(readi(ip, P2V(pa), offset+i, n) != n)
|
2011-01-11 18:01:13 +00:00
|
|
|
return -1;
|
2010-09-02 20:23:15 +00:00
|
|
|
}
|
2011-01-11 18:01:13 +00:00
|
|
|
return 0;
|
2010-09-02 20:23:15 +00:00
|
|
|
}
|
|
|
|
|
|
2011-02-20 02:17:55 +00:00
|
|
|
// Allocate page tables and physical memory to grow process from oldsz to
|
|
|
|
|
// newsz, which need not be page aligned. Returns new size or 0 on error.
|
2010-07-23 16:52:35 +00:00
|
|
|
int
|
2010-09-02 22:28:36 +00:00
|
|
|
allocuvm(pde_t *pgdir, uint oldsz, uint newsz)
|
2010-07-23 16:52:35 +00:00
|
|
|
{
|
2011-01-11 18:51:40 +00:00
|
|
|
char *mem;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint64 a;
|
2011-01-11 18:01:13 +00:00
|
|
|
|
2011-08-24 14:24:40 +00:00
|
|
|
if(newsz >= KERNBASE)
|
2010-07-23 16:52:35 +00:00
|
|
|
return 0;
|
2011-01-11 18:01:13 +00:00
|
|
|
if(newsz < oldsz)
|
|
|
|
|
return oldsz;
|
|
|
|
|
|
2011-01-11 18:51:40 +00:00
|
|
|
a = PGROUNDUP(oldsz);
|
|
|
|
|
for(; a < newsz; a += PGSIZE){
|
2011-01-11 18:01:13 +00:00
|
|
|
mem = kalloc();
|
2010-09-02 22:28:36 +00:00
|
|
|
if(mem == 0){
|
|
|
|
|
deallocuvm(pgdir, newsz, oldsz);
|
|
|
|
|
return 0;
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
2010-09-02 22:28:36 +00:00
|
|
|
memset(mem, 0, PGSIZE);
|
2016-08-24 17:40:06 +00:00
|
|
|
if(mappages(pgdir, (char*)a, PGSIZE, V2P(mem), PTE_W|PTE_U) < 0){
|
2016-08-08 17:06:38 +00:00
|
|
|
deallocuvm(pgdir, newsz, oldsz);
|
|
|
|
|
kfree(mem);
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
2011-01-11 18:01:13 +00:00
|
|
|
return newsz;
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
|
|
|
|
|
2010-09-02 22:28:36 +00:00
|
|
|
// Deallocate user pages to bring the process size from oldsz to
|
|
|
|
|
// newsz. oldsz and newsz need not be page-aligned, nor does newsz
|
|
|
|
|
// need to be less than oldsz. oldsz can be larger than the actual
|
|
|
|
|
// process size. Returns the new process size.
|
2010-08-10 21:08:41 +00:00
|
|
|
int
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
deallocuvm(pde_t *pgdir, uint64 oldsz, uint64 newsz)
|
2010-08-10 21:08:41 +00:00
|
|
|
{
|
2011-01-11 18:01:13 +00:00
|
|
|
pte_t *pte;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint64 a, pa;
|
2011-01-11 18:01:13 +00:00
|
|
|
|
|
|
|
|
if(newsz >= oldsz)
|
|
|
|
|
return oldsz;
|
|
|
|
|
|
2011-01-11 18:51:40 +00:00
|
|
|
a = PGROUNDUP(newsz);
|
|
|
|
|
for(; a < oldsz; a += PGSIZE){
|
2011-08-10 01:56:43 +00:00
|
|
|
pte = walkpgdir(pgdir, (char*)a, 0);
|
2011-09-02 01:29:09 +00:00
|
|
|
if(!pte)
|
2016-09-26 16:21:01 +00:00
|
|
|
a = PGADDR(PDX(a) + 1, 0, 0) - PGSIZE;
|
2011-09-02 01:29:09 +00:00
|
|
|
else if((*pte & PTE_P) != 0){
|
2011-01-11 18:01:13 +00:00
|
|
|
pa = PTE_ADDR(*pte);
|
2010-08-10 21:08:41 +00:00
|
|
|
if(pa == 0)
|
2010-09-02 22:28:36 +00:00
|
|
|
panic("kfree");
|
2016-08-24 17:40:06 +00:00
|
|
|
char *v = P2V(pa);
|
2011-08-01 01:27:02 +00:00
|
|
|
kfree(v);
|
2010-08-10 21:08:41 +00:00
|
|
|
*pte = 0;
|
|
|
|
|
}
|
|
|
|
|
}
|
2011-01-11 18:01:13 +00:00
|
|
|
return newsz;
|
2010-08-10 21:08:41 +00:00
|
|
|
}
|
|
|
|
|
|
2010-09-02 20:36:38 +00:00
|
|
|
// Free a page table and all the physical memory pages
|
2010-08-05 20:00:59 +00:00
|
|
|
// in the user part.
|
2010-07-23 16:52:35 +00:00
|
|
|
void
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
freevm(pde_t *pml4, uint64 sz)
|
2010-07-23 16:52:35 +00:00
|
|
|
{
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint i, j, k;
|
|
|
|
|
pde_t *pdp, *pd, *pt;
|
2010-07-23 16:52:35 +00:00
|
|
|
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
if(pml4 == 0)
|
2010-09-02 19:18:19 +00:00
|
|
|
panic("freevm: no pgdir");
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
|
|
|
|
|
deallocuvm(pml4, sz, 0);
|
2010-09-01 04:41:25 +00:00
|
|
|
for(i = 0; i < NPDENTRIES; i++){
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
if(pml4[i] & PTE_P){
|
|
|
|
|
pdp = (pdpe_t*)P2V(PTE_ADDR(pml4[i]));
|
|
|
|
|
for(j = 0; j < NPDENTRIES; j++){
|
|
|
|
|
if(pdp[j] & PTE_P){
|
|
|
|
|
pd = (pde_t*)P2V(PTE_ADDR(pdp[j]));
|
|
|
|
|
for(k = 0; k < NPDENTRIES; k++){
|
|
|
|
|
if(pd[k] & PTE_P) {
|
|
|
|
|
pt = (pde_t*)P2V(PTE_ADDR(pd[k]));
|
|
|
|
|
kfree((char*)pt);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
kfree((char*)pd);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
kfree((char*)pdp);
|
2011-08-01 01:27:02 +00:00
|
|
|
}
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
kfree((char*)pml4);
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
|
|
|
|
|
2011-09-02 18:35:58 +00:00
|
|
|
// Clear PTE_U on a page. Used to create an inaccessible
|
|
|
|
|
// page beneath the user stack.
|
|
|
|
|
void
|
2011-09-02 18:37:04 +00:00
|
|
|
clearpteu(pde_t *pgdir, char *uva)
|
2011-09-02 18:35:58 +00:00
|
|
|
{
|
|
|
|
|
pte_t *pte;
|
|
|
|
|
|
|
|
|
|
pte = walkpgdir(pgdir, uva, 0);
|
|
|
|
|
if(pte == 0)
|
2011-09-02 18:37:04 +00:00
|
|
|
panic("clearpteu");
|
2011-09-02 18:35:58 +00:00
|
|
|
*pte &= ~PTE_U;
|
|
|
|
|
}
|
|
|
|
|
|
2010-09-02 20:36:38 +00:00
|
|
|
// Given a parent process's page table, create a copy
|
2010-08-06 15:12:18 +00:00
|
|
|
// of it for a child.
|
2010-07-23 16:52:35 +00:00
|
|
|
pde_t*
|
|
|
|
|
copyuvm(pde_t *pgdir, uint sz)
|
|
|
|
|
{
|
2011-01-11 18:01:13 +00:00
|
|
|
pde_t *d;
|
2010-07-23 16:52:35 +00:00
|
|
|
pte_t *pte;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint64 pa, i;
|
|
|
|
|
uint flags;
|
2010-07-23 16:52:35 +00:00
|
|
|
char *mem;
|
|
|
|
|
|
2011-09-13 17:14:52 +00:00
|
|
|
if((d = setupkvm()) == 0)
|
2011-01-11 18:01:13 +00:00
|
|
|
return 0;
|
2010-09-01 04:41:25 +00:00
|
|
|
for(i = 0; i < sz; i += PGSIZE){
|
2011-09-02 18:28:44 +00:00
|
|
|
if((pte = walkpgdir(pgdir, (void *) i, 0)) == 0)
|
2011-02-20 02:17:55 +00:00
|
|
|
panic("copyuvm: pte should exist");
|
2010-09-01 21:14:58 +00:00
|
|
|
if(!(*pte & PTE_P))
|
2011-02-20 02:17:55 +00:00
|
|
|
panic("copyuvm: page not present");
|
2010-09-01 21:14:58 +00:00
|
|
|
pa = PTE_ADDR(*pte);
|
2013-03-04 21:16:54 +00:00
|
|
|
flags = PTE_FLAGS(*pte);
|
2011-01-11 18:01:13 +00:00
|
|
|
if((mem = kalloc()) == 0)
|
2010-09-01 21:14:58 +00:00
|
|
|
goto bad;
|
2016-08-24 17:40:06 +00:00
|
|
|
memmove(mem, (char*)P2V(pa), PGSIZE);
|
2018-08-30 17:30:50 +00:00
|
|
|
if(mappages(d, (void*)i, PGSIZE, V2P(mem), flags) < 0) {
|
|
|
|
|
kfree(mem);
|
2010-09-01 21:14:58 +00:00
|
|
|
goto bad;
|
2018-08-30 17:30:50 +00:00
|
|
|
}
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
|
|
|
|
return d;
|
2010-09-01 04:27:12 +00:00
|
|
|
|
|
|
|
|
bad:
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
freevm(d, sz);
|
2010-09-01 04:27:12 +00:00
|
|
|
return 0;
|
2010-07-23 16:52:35 +00:00
|
|
|
}
|
|
|
|
|
|
2011-02-20 02:17:55 +00:00
|
|
|
//PAGEBREAK!
|
2011-08-01 01:27:02 +00:00
|
|
|
// Map user virtual address to kernel address.
|
2011-02-20 02:17:55 +00:00
|
|
|
char*
|
|
|
|
|
uva2ka(pde_t *pgdir, char *uva)
|
|
|
|
|
{
|
|
|
|
|
pte_t *pte;
|
|
|
|
|
|
2011-08-10 01:56:43 +00:00
|
|
|
pte = walkpgdir(pgdir, uva, 0);
|
2011-02-20 02:17:55 +00:00
|
|
|
if((*pte & PTE_P) == 0)
|
|
|
|
|
return 0;
|
|
|
|
|
if((*pte & PTE_U) == 0)
|
|
|
|
|
return 0;
|
2016-08-24 17:40:06 +00:00
|
|
|
return (char*)P2V(PTE_ADDR(*pte));
|
2011-02-20 02:17:55 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// Copy len bytes from p to user address va in page table pgdir.
|
|
|
|
|
// Most useful when pgdir is not the current page table.
|
2010-09-27 20:14:33 +00:00
|
|
|
// uva2ka ensures this only works for PTE_U pages.
|
|
|
|
|
int
|
2011-02-20 02:17:55 +00:00
|
|
|
copyout(pde_t *pgdir, uint va, void *p, uint len)
|
2010-09-27 20:14:33 +00:00
|
|
|
{
|
2011-01-11 18:01:13 +00:00
|
|
|
char *buf, *pa0;
|
Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.
The x86-64 doesn't just add two levels to page tables to support 64 bit
addresses, but is a different processor. For example, calling conventions,
system calls, and segmentation are different from 32-bit x86. Segmentation is
basically gone, but gs/fs in combination with MSRs can be used to hold a
per-core pointer. In general, x86-64 is more straightforward than 32-bit
x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch.
A summary of the changes is as follows:
- Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu),
because xv6's boot loader doesn't understand 64bit ELF files. And, we don't
care anymore about booting.
- Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img,
bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than
MAXFILE!
- Update gdb.tmpl to be for i386 or x86-64
- Console/printf: use stdarg.h and treat 64-bit addresses different from ints
(32-bit)
- Update elfhdr to be 64 bit
- entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page
table in 32-bit mode before switching to 64-bit mode, share code for entering
boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the
kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state
mostly disappear.)
- exec.c: fix passing argv (64-bit now instead of 32-bit).
- initcode.c: use syscall instead of int.
- kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of
address space!
- proc.c: initial return is through new syscall path instead of trapret.
- proc.h: update struct cpu to have some scratch space since syscall saves less
state than int, update struct context to reflect x86-64 calling conventions.
- swtch: simplify for x86-64 calling conventions.
- syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are
passed through registers), and fetchaddr to read a 64-bit value from user space.
- sysfile: update to handle pointers from user space (e.g., sys_exec), which are
64 bits.
- trap.c: no special trap vector for sys calls, because x86-64 has a different
plan for system calls.
- trapasm: one plan for syscalls and one plan for traps (interrupt and
exceptions). On x86-64, the kernel is responsible for switching user/kernel
stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR
GS_KERN_BASE to point to the core's cpu structure (using swapgs).
- types.h: add uint64, and change pde_t to uint64
- usertests: exit() when fork fails, which helped in tracking down one of the
bugs in the switch from 32-bit to 64-bit
- vectors: update to make them 64 bits
- vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local
state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task
segment to set kernel stack for interrupts (but simpler than in 32-bit mode),
add an extra argument to freevm (size of user part of address space) to avoid
checking all entries till KERNBASE (there are MANY TB before the top 1TB).
- x86: update trapframe to have 64-bit entries, which is what the processor
pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr,
which needs the gcc directives packed and aligned.
TODO:
- use int32 instead of int?
- simplify curproc(). xv6 has per-cpu state again, but this time it must have it.
- avoid repetition in walkpgdir
- fix validateint() in usertests.c
- fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2018-09-23 12:24:42 +00:00
|
|
|
uint64 n, va0;
|
2011-09-01 16:02:49 +00:00
|
|
|
|
2011-02-20 02:17:55 +00:00
|
|
|
buf = (char*)p;
|
2010-09-27 20:14:33 +00:00
|
|
|
while(len > 0){
|
2011-01-11 18:01:13 +00:00
|
|
|
va0 = (uint)PGROUNDDOWN(va);
|
|
|
|
|
pa0 = uva2ka(pgdir, (char*)va0);
|
2010-09-27 20:14:33 +00:00
|
|
|
if(pa0 == 0)
|
2011-01-11 18:01:13 +00:00
|
|
|
return -1;
|
|
|
|
|
n = PGSIZE - (va - va0);
|
2010-09-27 20:14:33 +00:00
|
|
|
if(n > len)
|
|
|
|
|
n = len;
|
|
|
|
|
memmove(pa0 + (va - va0), buf, n);
|
|
|
|
|
len -= n;
|
|
|
|
|
buf += n;
|
|
|
|
|
va = va0 + PGSIZE;
|
|
|
|
|
}
|
2011-01-11 18:01:13 +00:00
|
|
|
return 0;
|
2010-09-27 20:14:33 +00:00
|
|
|
}
|
2014-08-29 21:06:49 +00:00
|
|
|
|
|
|
|
|
//PAGEBREAK!
|
|
|
|
|
// Blank page.
|
|
|
|
|
//PAGEBREAK!
|
|
|
|
|
// Blank page.
|
|
|
|
|
//PAGEBREAK!
|
|
|
|
|
// Blank page.
|
|
|
|
|
|
