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Kernel: Set an appropriate GDT for 64-bit mode

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This commit is contained in:
Gunnar Beutner 2021-06-24 13:04:41 +02:00 • committed by Andreas Kling
parent d84abe51f5
commit 4c555684b7
1 changed files with 19 additions and 3 deletions
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22
Kernel/Arch/x86/x86_64/Boot/boot.S
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@ -80,13 +80,23 @@ boot_pd3 : 512 pde's
13: boot_pd3_pts[13] (3098-3100MB) (pseudo 512 4KB pages)
14: boot_pd3_pts[14] (3100-3102MB) (pseudo 512 4KB pages)
15: boot_pd3_pts[15] (3102-3104MB) (pseudo 512 4KB pages)
16: boot_pd3_pt1023 (4094-4096MB) (for page table mappings)
the 9 page tables each contain 512 pte's that map individual 4KB pages
*/
gdt64:
.quad 0
gdt64code:
.quad (1<<43) | (1<<44) | (1<<47) | (1<<53) /* executable, code segment, present, 64-bit */
gdt64ptr:
.short . - gdt64 - 1
.quad gdt64
.set code64_sel, gdt64code - gdt64
start:
cli
cld
@ -250,8 +260,13 @@ start:
addl $0xc0000000, %ebx
movl %ebx, multiboot_info_ptr
lgdt gdt64ptr
ljmpl $code64_sel, $1f
.code64
1:
call init
add $4, %esp
add $4, %rsp
cli
loop:
@ -319,7 +334,8 @@ apic_ap_start32:
movl $0x80000001, %eax
cpuid
testl $0x100000, %edx
je (1f - apic_ap_start + 0x8000)
// TODO: Uncomment this
//je (1f - apic_ap_start + 0x8000)
/* turn on IA32_EFER.NXE */
movl $0xc0000080, %ecx
rdmsr