xv6-65oo2/main.c
2016-09-02 15:27:28 -04:00

116 lines
3.2 KiB
C

#include "types.h"
#include "defs.h"
#include "param.h"
#include "memlayout.h"
#include "mmu.h"
#include "proc.h"
#include "x86.h"
static void startothers(void);
static void mpmain(void) __attribute__((noreturn));
extern pde_t *kpgdir;
extern char end[]; // first address after kernel loaded from ELF file
// Bootstrap processor starts running C code here.
// Allocate a real stack and switch to it, first
// doing some setup required for memory allocator to work.
int
main(void)
{
kinit1(end, P2V(4*1024*1024)); // phys page allocator
kvmalloc(); // kernel page table
mpinit(); // detect other processors
lapicinit(); // interrupt controller
seginit(); // segment descriptors
cprintf("\ncpu%d: starting xv6\n\n", cpunum());
picinit(); // another interrupt controller
ioapicinit(); // another interrupt controller
consoleinit(); // console hardware
uartinit(); // serial port
pinit(); // process table
tvinit(); // trap vectors
binit(); // buffer cache
fileinit(); // file table
ideinit(); // disk
if(!ismp)
timerinit(); // uniprocessor timer
startothers(); // start other processors
kinit2(P2V(4*1024*1024), P2V(PHYSTOP)); // must come after startothers()
userinit(); // first user process
mpmain(); // finish this processor's setup
}
// Other CPUs jump here from entryother.S.
static void
mpenter(void)
{
switchkvm();
seginit();
lapicinit();
mpmain();
}
// Common CPU setup code.
static void
mpmain(void)
{
cprintf("cpu%d: starting\n", cpunum());
idtinit(); // load idt register
xchg(&cpu->started, 1); // tell startothers() we're up
scheduler(); // start running processes
}
pde_t entrypgdir[]; // For entry.S
// Start the non-boot (AP) processors.
static void
startothers(void)
{
extern uchar _binary_entryother_start[], _binary_entryother_size[];
uchar *code;
struct cpu *c;
char *stack;
// Write entry code to unused memory at 0x7000.
// The linker has placed the image of entryother.S in
// _binary_entryother_start.
code = P2V(0x7000);
memmove(code, _binary_entryother_start, (uint)_binary_entryother_size);
for(c = cpus; c < cpus+ncpu; c++){
if(c == cpus+cpunum()) // We've started already.
continue;
// Tell entryother.S what stack to use, where to enter, and what
// pgdir to use. We cannot use kpgdir yet, because the AP processor
// is running in low memory, so we use entrypgdir for the APs too.
stack = kalloc();
*(void**)(code-4) = stack + KSTACKSIZE;
*(void**)(code-8) = mpenter;
*(int**)(code-12) = (void *) V2P(entrypgdir);
lapicstartap(c->apicid, V2P(code));
// wait for cpu to finish mpmain()
while(c->started == 0)
;
}
}
// The boot page table used in entry.S and entryother.S.
// Page directories (and page tables) must start on page boundaries,
// hence the __aligned__ attribute.
// PTE_PS in a page directory entry enables 4Mbyte pages.
__attribute__((__aligned__(PGSIZE)))
pde_t entrypgdir[NPDENTRIES] = {
// Map VA's [0, 4MB) to PA's [0, 4MB)
[0] = (0) | PTE_P | PTE_W | PTE_PS,
// Map VA's [KERNBASE, KERNBASE+4MB) to PA's [0, 4MB)
[KERNBASE>>PDXSHIFT] = (0) | PTE_P | PTE_W | PTE_PS,
};
//PAGEBREAK!
// Blank page.
//PAGEBREAK!