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Remove cpuid checks

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This commit is contained in:
Mark 2025-03-02 20:35:05 -08:00
parent de3ff45f1b
commit f5ede33bc8
Signed by: Mark
GPG Key ID: C6D63995FE72FD80
2 changed files with 0 additions and 181 deletions
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176
bios/cpuid.asm
View File

@ -1,176 +0,0 @@
SECTION .text
USE16
cpuid_required_features:
.edx equ cpuid_edx.fpu | cpuid_edx.pse | cpuid_edx.pge | cpuid_edx.fxsr
.ecx equ 0
cpuid_check:
; If bit 21 of EFLAGS can be changed, then CPUID is supported
pushfd ;Save EFLAGS
pushfd ;Store EFLAGS
xor dword [esp],0x00200000 ;Invert the ID bit in stored EFLAGS
popfd ;Load stored EFLAGS (with ID bit inverted)
pushfd ;Store EFLAGS again (ID bit may or may not be inverted)
pop eax ;eax = modified EFLAGS (ID bit may or may not be inverted)
xor eax,[esp] ;eax = whichever bits were changed
popfd ;Restore original EFLAGS
test eax,0x00200000 ;eax = zero if ID bit can't be changed, else non-zero
jz .no_cpuid
mov eax, 1
cpuid
and edx, cpuid_required_features.edx
cmp edx, cpuid_required_features.edx
jne .error
and ecx, cpuid_required_features.ecx
cmp ecx, cpuid_required_features.ecx
jne .error
ret
.no_cpuid:
mov si, .msg_cpuid
call print
mov si, .msg_line
call print
jmp .halt
.error:
push ecx
push edx
mov si, .msg_features
call print
mov si, .msg_line
call print
mov si, .msg_edx
call print
pop ebx
push ebx
shr ebx, 16
call print_hex
pop ebx
call print_hex
mov si, .msg_must_contain
call print
mov ebx, cpuid_required_features.edx
shr ebx, 16
call print_hex
mov ebx, cpuid_required_features.edx
call print_hex
mov si, .msg_line
call print
mov si, .msg_ecx
call print
pop ebx
push ebx
shr ebx, 16
call print_hex
pop ebx
call print_hex
mov si, .msg_must_contain
call print
mov ebx, cpuid_required_features.ecx
shr ebx, 16
call print_hex
mov ebx, cpuid_required_features.ecx
call print_hex
mov si, .msg_line
call print
.halt:
cli
hlt
jmp .halt
.msg_cpuid: db "CPUID not supported",0
.msg_features: db "Required CPU features are not present",0
.msg_line: db 13,10,0
.msg_edx: db "EDX ",0
.msg_ecx: db "ECX ",0
.msg_must_contain: db " must contain ",0
cpuid_edx:
.fpu equ 1 << 0
.vme equ 1 << 1
.de equ 1 << 2
.pse equ 1 << 3
.tsc equ 1 << 4
.msr equ 1 << 5
.pae equ 1 << 6
.mce equ 1 << 7
.cx8 equ 1 << 8
.apic equ 1 << 9
.sep equ 1 << 11
.mtrr equ 1 << 12
.pge equ 1 << 13
.mca equ 1 << 14
.cmov equ 1 << 15
.pat equ 1 << 16
.pse_36 equ 1 << 17
.psn equ 1 << 18
.clfsh equ 1 << 19
.ds equ 1 << 21
.acpi equ 1 << 22
.mmx equ 1 << 23
.fxsr equ 1 << 24
.sse equ 1 << 25
.sse2 equ 1 << 26
.ss equ 1 << 27
.htt equ 1 << 28
.tm equ 1 << 29
.ia64 equ 1 << 30
.pbe equ 1 << 31
cpuid_ecx:
.sse3 equ 1 << 0
.pclmulqdq equ 1 << 1
.dtes64 equ 1 << 2
.monitor equ 1 << 3
.ds_cpl equ 1 << 4
.vmx equ 1 << 5
.smx equ 1 << 6
.est equ 1 << 7
.tm2 equ 1 << 8
.ssse3 equ 1 << 9
.cnxt_id equ 1 << 10
.sdbg equ 1 << 11
.fma equ 1 << 12
.cmpxchg16b equ 1 << 13
.xtpr equ 1 << 14
.pdcm equ 1 << 15
.pcid equ 1 << 17
.dca equ 1 << 18
.sse4_1 equ 1 << 19
.sse4_2 equ 1 << 20
.x2apic equ 1 << 21
.movbe equ 1 << 22
.popcnt equ 1 << 23
.tsc_deadline equ 1 << 24
.aes equ 1 << 25
.xsave equ 1 << 26
.osxsave equ 1 << 27
.avx equ 1 << 28
.f16c equ 1 << 29
.rdrand equ 1 << 30
.hypervisor equ 1 << 31

5
bios/stage2.asm
View File

@ -8,10 +8,6 @@ stage2.entry:
call print_char
call print_line
; check for required features
call cpuid_check
; enable A20-Line via IO-Port 92, might not work on all motherboards
in al, 0x92
or al, 2
@ -20,7 +16,6 @@ stage2.entry:
mov dword [protected_mode.func], stage3.entry
jmp protected_mode.entry
%include "cpuid.asm"
%include "gdt.asm"
%include "protected_mode.asm"
%include "thunk.asm"