我寫了一個非常簡單的C內核和bootloader。我加載在QEMU內核是這樣的:QEMU在執行方法時崩潰
qemu-system-i386 kernel.image
當我加載從實模式轉換到保護模式(這一步成功完成)和main
方法內核和開關啓動執行其他方法這樣 void foo(int a, int b, int c, int d, int e) {return;}
。但它的執行導致QEMU崩潰。但是,如果我重寫foo
方法void foo(int a, int b, int c, int d) {return;}
- 一切都會好的。以下是錯誤信息: (QEMU)QEMU:致命的:試圖在0xf4000010
EAX=ffffffff EBX=00001000 ECX=00000000 EDX=00000000
ESI=00000000 EDI=00000000 EBP=ae00008f ESP=00008fcd
EIP=f4000010 EFL=00000006 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
CS =0008 00000000 ffffffff 00cf9a00 DPL=0 CS32 [-R-]
SS =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
DS =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
FS =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
GS =0010 00000000 ffffffff 00cf9300 DPL=0 DS [-WA]
LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
GDT= 00007c75 00000017
IDT= 00000000 000003ff
CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000
DR6=ffff0ff0 DR7=00000400
CCS=00000000 CCD=00008fc5 CCO=INCL
EFER=0000000000000000
FCW=037f FSW=0000 [ST=0] FTW=00 MXCSR=00001f80
FPR0=0000000000000000 0000 FPR1=0000000000000000 0000
FPR2=0000000000000000 0000 FPR3=0000000000000000 0000
FPR4=0000000000000000 0000 FPR5=0000000000000000 0000
FPR6=0000000000000000 0000 FPR7=0000000000000000 0000
XMM00=00000000000000000000000000000000 XMM01=00000000000000000000000000000000
XMM02=00000000000000000000000000000000 XMM03=00000000000000000000000000000000
XMM04=00000000000000000000000000000000 XMM05=00000000000000000000000000000000
XMM06=00000000000000000000000000000000 XMM07=00000000000000000000000000000000
我bootloader.S
KERNEL_OFFSET equ 0x1000
[org 0x7c00]
[bits 16]
mov bp, 0x8000
mov sp, bp
mov bx, bootstring
call print
mov [BOOT_DRIVE], dl
mov dh, 3h
mov bx, KERNEL_OFFSET
call load_kernel
call enable_A20
call init_protected
loop:
jmp loop
bootstring: db "Loading...", 0
BOOT_DRIVE: db 0
print:
mov ah, 0xE
mov al, [bx]
cmp al, 0
jz print_done
int 0x10
inc bx
jmp print
print_done:
ret
load_kernel:
push dx
mov ah, 0x02
mov al, dh
mov ch, 0
mov cl, 2
mov dh, 0
int 0x13
jc load_error
pop dx
cmp al, dh
jne load_error
ret
load_error:
mov bx, load_err_msg
call print
jmp $
enable_A20:
cli
call a20wait
mov al, 0xAD
out 0x64, al
call a20wait
mov al, 0xD0
out 0x64, al
call a20wait2
in al, 0x60
push eax
call a20wait
mov al, 0xD1
out 0x64, al
call a20wait
pop eax
or al, 2
out 0x60, al
call a20wait
mov al, 0xAE
out 0x64, al
call a20wait
sti
ret
a20wait:
in al, 0x64
test al, 2
jnz a20wait
ret
a20wait2:
in al, 0x64
test al, 1
jz a20wait2
ret
load_err_msg: db "Cannot load from disk", 0
gdt:
gdt_null:
dd 0
dd 0
gdt_cs:
dw 0xffff
dw 0
db 0
db 10011010b
db 11001111b
db 0
gdt_ds:
dw 0xffff
dw 0
db 0
db 10010010b
db 11001111b
db 0
gdt_end:
gdt_desc:
dw gdt_end - gdt - 1
dd gdt
CODE_SEG equ gdt_cs - gdt
DATA_SEG equ gdt_ds - gdt
[bits 16]
init_protected:
cli
xor ax, ax
mov ds, ax
mov es, ax
mov ax, 0x9000
mov ss, ax
mov sp, 0xFFFF
lgdt [gdt_desc]
mov eax, cr0
or eax, 0x1
mov cr0, eax
jmp CODE_SEG:start_protected
[bits 32]
start_protected:
mov ax, DATA_SEG
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax
mov esp, 0x9000
call KERNEL_OFFSET
times 510 -($ - $$) db 0
dw 0xAA55
如果我錯了,外面RAM或ROM執行代碼?
你真的希望我們在不給我們內核的情況下調試你的內核嗎?顯然,你以某種方式違反了保護條款,但實際上怎麼說都不可能。 – 2015-02-07 17:31:29
真的嗎?你是認真的嗎?將代碼提供給內核。 – SevenBits 2015-02-07 18:12:00
@MarcusMüller對不起,我editet發佈;) – dvigal 2015-02-07 19:31:29