Make kernel to boot in x32

This commit is contained in:
Alex
2023-05-11 18:34:21 +03:00
parent 15637438da
commit 149d8ba790
19 changed files with 803 additions and 530 deletions

View File

@ -18,50 +18,3 @@
.intel_syntax noprefix
.code32
.equ PAGE_TABLE_SIZE, 0x4
.section .bootstrap.data
.align 0x1000
.global BootPageTable
BootPageTable:
.rept 0x10000 /* 0x4000 bytes will be used in UpdatePageTable */
.long 0
.endr
.section .bootstrap.text
.global UpdatePageTable
UpdatePageTable:
mov edi, (BootPageTable + 0x0000) /* First PML4E */
mov eax, (BootPageTable + 0x1000) /* First PDPTE */
or eax, 0b11 /* Bitwise OR on rax (PDPTE) with 11b (Present, Write) */
mov dword [edi], eax /* Write 11b to PML4E */
mov edi, (BootPageTable + 0x1000) /* First PDPTE */
mov eax, (BootPageTable + 0x2000) /* First PDE */
or eax, 0b11 /* Bitwise OR on rax (PDE) with 11b (Present, Write) */
mov ecx, PAGE_TABLE_SIZE /* For loop instruction */
mov ebx, 0x0 /* Value to store in the next 4 bytes */
.FillPageTableLevel3:
mov dword [edi], eax /* Store modified PDE in PDPTE */
mov dword [edi + 4], ebx /* Store the rbx value in the next 4 bytes */
add eax, 0x1000 /* Increment (page size) */
adc ebx, 0 /* Add 0 to carry flag */
add edi, 8 /* Add 8 to rdi (next PDE) */
loop .FillPageTableLevel3 /* Loop until rcx is 0 */
mov edi, (BootPageTable + 0x2000) /* First PDE */
mov eax, 0b10000011 /* Present, Write, Large Page */
mov ecx, (512 * PAGE_TABLE_SIZE) /* For loop instruction */
mov ebx, 0x0 /* Value to store in the next 4 bytes */
.FillPageTableLevel2:
mov dword [edi], eax /* Store modified PDE in PDPTE */
mov dword [edi + 4], ebx /* Store the rbx value in the next 4 bytes */
add eax, 1 << 21 /* Increment (page size) */
adc ebx, 0 /* Add 0 (carry flag) to rbx to increment if there was a carry */
add edi, 8 /* Add 8 to rdi (next PDE) */
loop .FillPageTableLevel2 /* Loop until rcx is 0 */
ret