diff options
| author | Ian Moffett <ian@osmora.org> | 2025-11-17 19:18:01 -0500 |
|---|---|---|
| committer | Ian Moffett <ian@osmora.org> | 2025-11-17 19:21:45 -0500 |
| commit | 96f377cc12baf1ab808925ac5ce7f3b3a9a2be19 (patch) | |
| tree | 73feee6fa2b0fc4ff36708d9e026f2ae58ab0e6b /sys/arch/amd64/boot/apboot.asm | |
| parent | bf94209175e843462ef9965fc7003452d55ea041 (diff) | |
kern/amd64: Bring application cores to long mode
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'sys/arch/amd64/boot/apboot.asm')
| -rw-r--r-- | sys/arch/amd64/boot/apboot.asm | 54 |
1 files changed, 51 insertions, 3 deletions
diff --git a/sys/arch/amd64/boot/apboot.asm b/sys/arch/amd64/boot/apboot.asm index b9c3ad7..8c16319 100644 --- a/sys/arch/amd64/boot/apboot.asm +++ b/sys/arch/amd64/boot/apboot.asm @@ -30,9 +30,57 @@ [bits 16] [org 0x1000] +%define AP_BUDA 0x3000 +%define IA32_EFER 0xC0000080 + +[bits 16] _start: - cli - hlt - jmp _start + mov al, 0xFF ;; Mask i8259 inputs + out 0x21, al ;; Disable master PIC + out 0xA1, al ;; Disable slave PIC + + mov eax, dword [AP_BUDA] ;; BUDA.CR3 -> EAX + mov cr3, eax ;; EAX -> CR3 + + mov eax, cr4 ;; CR4 -> EAX + or eax, 0xA0 ;; Enable physical address extension + PGE + mov cr4, eax ;; Write it back + + mov ecx, IA32_EFER ;; Read IA32_EFER + rdmsr ;; -> EAX + or eax, 0xD00 ;; Set EFER.LME + defaults + wrmsr ;; Write it back + + mov eax, cr0 ;; CR0 -> EAX + or eax, 0x80000001 ;; CR0 |= PG/PM + mov cr0, eax ;; Write it back + + lgdt [GDTR] + jmp 0x08:thunk64 + +GDT: +.NULL: + dq 0x0000000000000000 ;; NULL DESCRIPTOR +.CODE: ;; --------------- + dq 0x00209A0000000000 ;; CODE DESCRIPTOR +.DATA: ;; --------------- + dq 0x0000920000000000 ;; DATA DESCRIPTOR +GDTR: ;; --------------- + dw $ - GDT - 1 ;; LIMIT + dq GDT ;; OFFSET + +[bits 64] +thunk64: + mov ax, 0x10 + mov ds, ax + mov es, ax + mov fs, ax + mov ss, ax + xor ax, ax + mov gs, ax + mov rsp, qword [AP_BUDA + 0x08] + mov rbx, qword [AP_BUDA + 0x10] + cld + jmp rbx times 4096 - ($ - $$) db 0 |