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Kernel: Use PML4T for 64-bit mode

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This commit is contained in:
Gunnar Beutner 2021-06-24 13:03:22 +02:00 • committed by Andreas Kling
parent 13e4093da4
commit d84abe51f5
1 changed files with 24 additions and 5 deletions
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29
Kernel/Arch/x86/x86_64/Boot/boot.S
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@ -10,6 +10,9 @@ kernel_cmdline:
.section .page_tables, "aw", @nobits .section .page_tables, "aw", @nobits
.align 4096 .align 4096
.global boot_pml4t
boot_pml4t:
.skip 4096
.global boot_pdpt .global boot_pdpt
boot_pdpt: boot_pdpt:
.skip 4096 .skip 4096
@ -41,7 +44,11 @@ boot_pd3_pt1023:
.type multiboot_info_ptr, @object .type multiboot_info_ptr, @object
/* /*
construct the following (32-bit PAE) page table layout: construct the following (64-bit PML4T) page table layout:
pml4t:
0: pdpt (0-512GB)
pdpt pdpt
@ -97,6 +104,18 @@ start:
movl $(kernel_cmdline - 0xc0000000), %edi movl $(kernel_cmdline - 0xc0000000), %edi
rep movsl rep movsl
/* clear pml4t */
movl $(boot_pml4t - 0xc0000000), %edi
movl $1024, %ecx
xorl %eax, %eax
rep stosl
/* set up pml4t[0] */
movl $(boot_pml4t - 0xc0000000), %edi
movl $(boot_pdpt - 0xc0000000), 0(%edi)
/* R/W + Present */
orl $0x3, 0(%edi)
/* clear pdpt */ /* clear pdpt */
movl $(boot_pdpt - 0xc0000000), %edi movl $(boot_pdpt - 0xc0000000), %edi
movl $1024, %ecx movl $1024, %ecx
@ -105,8 +124,8 @@ start:
/* set up pdpt[0] and pdpt[3] */ /* set up pdpt[0] and pdpt[3] */
movl $(boot_pdpt - 0xc0000000), %edi movl $(boot_pdpt - 0xc0000000), %edi
movl $((boot_pd0 - 0xc0000000) + 1), 0(%edi) movl $((boot_pd0 - 0xc0000000) + 3), 0(%edi)
movl $((boot_pd3 - 0xc0000000) + 1), 24(%edi) movl $((boot_pd3 - 0xc0000000) + 3), 24(%edi)
/* clear pd0 */ /* clear pd0 */
movl $(boot_pd0 - 0xc0000000), %edi movl $(boot_pd0 - 0xc0000000), %edi
@ -184,8 +203,8 @@ start:
orl $0x3, 4088(%edi) orl $0x3, 4088(%edi)
movl $0, 4092(%edi) movl $0, 4092(%edi)
/* point CR3 to PDPT */ /* point CR3 to PML4T */
movl $(boot_pdpt - 0xc0000000), %eax movl $(boot_pml4t - 0xc0000000), %eax
movl %eax, %cr3 movl %eax, %cr3
/* enable PAE + PSE */ /* enable PAE + PSE */