StupidOS/kernel/mm/mm.inc

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;; File: mm.inc
;; StupidOS Memory Manager
;;
;; About: Memory Layout
;;
;; > Virtual
;; > 0xFFFFFFFF +---------------+
;; > | |
;; > | Device Memory |
;; > | |
;; > +---------------+
;; > | |
;; > | Kernel Heap |
;; > | |
;; > KERN_END +---------------+
;; > | |
;; > | Stupid Kernel |
;; > | |
;; > 0xC0100000 +---------------+
;; > | I/O Space and |
;; > | phys memory |
;; > | Lower than 1M | kernel mode only
;; > 0xC0000000 +---------------+
;; > | | user mode
;; > | userspace |
;; > | |
;; > 0x00000000 +---------------+
;;
include "pmm.inc"
include "../sys/mmu.inc"
;; Macro: KV2P
;; Convert virtual address to physical
macro KV2P reg {
sub reg, KERNEL_VIRT_BASE
}
;; Macro: KP2V
;; Convert physical address to virtual
macro KP2V reg {
add reg, KERNEL_VIRT_BASE
}
;; Function: mm_kmap
mm_kmap:
push esp
mov ebp, esp
sub esp, 0x10
call pmm_alloc_page
mov [ebp-4], eax
; clear page dir
mov edi, eax
mov ecx, 4096
xor al, al
rep stosb
call pmm_alloc_page
xor esi, esi
xor ecx, ecx
mov edi, eax
@@:
mov edx, esi
or edx, (PTE_P or PTE_W)
mov [edi], edx
add edi, 4
add esi, 4096
inc ecx
cmp ecx, 1024
jb @b
or eax, (PDE_P or PDE_W)
mov edx, [ebp-4]
add edx, (768 * 4)
KV2P eax
mov [edx], eax
mov eax, [ebp-4]
leave
ret
;; Function: mm_clone_pte
;;
;; In:
;; EAX - source page table
;;
;; Out:
;; EAX - cloned page table
;;
mm_clone_pte:
push esp
mov ebp, esp
sub esp, 0x10
leave
ret
;; Function: mm_clone_pgdir
;;
;; In:
;; EAX - source page dir
;;
;; Out:
;; EAX - cloned page dir
mm_clone_pgdir:
push esp
mov ebp, esp
sub esp, 0x10
mov [ebp-4], eax
call pmm_alloc_page
mov [ebp-8], eax
mov ecx, 4096
mov edi, eax
xor al, al
rep stosb
xor ecx, ecx
.loop:
mov eax, [ebp-4]
add eax, ecx
mov eax, [eax]
cmp eax, 0
je .next
cmp ecx, (768*4)
jb @f
mov edx, [ebp-8]
add edx, ecx
mov [edx], eax
jmp .next
@@:
mov edx, eax
call pmm_alloc_page
.next:
add ecx, 4
cmp ecx, 4096
jb .loop
leave
ret
;; Function: mm_init
;; Initialize the memory manager
mm_init:
mov esi, szMsgMmInit
call klog
call mm_kmap
mov [pKernelPgDir], eax
; map whole memory
mov esi, 0x400000
mov ebx, (769 * 4)
.loop:
call pmm_alloc_page
xor ecx, ecx
mov edi, eax
@@:
mov edx, esi
or edx, (PTE_P or PTE_W)
mov [edi], edx
add edi, 4
add esi, 4096
inc ecx
cmp ecx, 1024
jb @b
or eax, (PDE_P or PDE_W)
mov edx, [pKernelPgDir]
add edx, ebx
add ebx, 4
KV2P eax
mov [edx], eax
cmp esi, [boot_structure.high_mem]
jb .loop
; reload cr3
mov eax, [pKernelPgDir]
KV2P eax
mov cr3, eax
push eax
mov esi, szMsgMmKernelPgDir
call klog
ret
;; Function: mm_mmap
;;
;; In:
;; XXX - addr
;; XXX - length
;; XXX - prot
;; XXX - flags
mm_mmap:
ret
;; Function: mm_munmap
;;
;; In:
;; XXX - addr
;; XXX - length
;;
mm_munmap:
ret
mm_wallk_pagedir:
ret
szMsgMmInit db "MM: initialize", 0
szMsgMmKernelPgDir db "MM: Kernel page dir at %x phys", 0
pKernelPgDir dd 0