QEMU black screen
Posted: Tue May 31, 2022 5:11 am
Hello,I made a OS run on floppy,it can run in qemu and vmware,then I modify it to a hard disk version,I use lba28 mode to read disk img,it can run in vmware normally,but can not run in qemu,the screen will become 1024*768 size,but is black screen,I have no idea what's going on here,the os is 32bit,segmentation,no paging,the loader is:
The qemu version is 7.0.0,and the start command is
Code: Select all
[INSTRSET "i486p"]
BOOTPACK_SEC_CNT EQU 128*1024/512
BOOTPACK_SEC EQU 578
BOOTPAK_ADR EQU 0x00280000
DISK_CACHE_ADR EQU 0x00100000
DISK_CAC0 EQU 0x00008000
VBE_MODE EQU 0x105 ;1024×768
;BOOT_INFO
CYLS EQU 0x0ff0
LEDS EQU 0x0ff1
VMODE EQU 0x0ff2
SCRNX EQU 0x0ff4
SCRNY EQU 0x0ff6
VRAM EQU 0x0ff8
SYS_ESP EQU 0x0ffc
PIC0_IMR EQU 0x0021
PIC1_IMR EQU 0x00a1
REGISTER_KBC_STA EQU 0x0064
REGISTER_KBC_CMD EQU 0x0064
REGISTER_KBC_DATA EQU 0x0060
CMD_KBC_WRITE_OUTREGISTER EQU 0xd1
CMD_KBC_OUTREGISTER_A20G_ENABLE EQU 0xdf ;A20GATE ON
ORG 0x8000
; DB "hello asmhead"
; DB 0
MOV AH,0x02
INT 0x16
MOV BYTE [LEDS],AL
; JMP scrn320
MOV AX,0x9000
MOV ES,AX
MOV DI,0x00 ;ES:DI=0x90000
MOV AX,0x4f00
INT 0x10
CMP AX,0x004f
JE vbe
scrn320:
MOV AH,0
MOV AL,0x13 ;320×200×8
INT 0x10
MOV BYTE [VMODE],8
MOV WORD [SCRNX],320
MOV WORD [SCRNY],200
MOV DWORD [VRAM],0xa0000
JMP setPIC
vbe:
MOV AX,[ES:DI+4] ;VBE
CMP AX,0x0200 ;2.0
JB scrn320
;0x105
MOV CX,VBE_MODE ;0x105
MOV AX,0x4f01
INT 0x10
CMP AX,0x004f
JNE scrn320
CMP BYTE [ES:DI+0x19],8
JNE scrn320
CMP BYTE [ES:DI+0x1b],4
JNE scrn320
MOV AX,WORD [ES:DI+0x00]
SHR AL,7
CMP AL,1
JNE scrn320
;0x105，1024× 768× 8bit
MOV AX,0x4f02
MOV BX,VBE_MODE+0x4000
INT 0x10
MOV BYTE [VMODE],8
MOV AX,WORD [ES:DI+0x12] ;x
MOV WORD [SCRNX],AX
MOV AX,WORD [ES:DI+0x14] ;y
MOV WORD [SCRNY],AX
MOV EAX,DWORD [ES:DI+0x28] ;VRAM
MOV DWORD [VRAM],EAX
setPIC:
MOV AL,0xff
OUT PIC0_IMR,AL
NOP ;
MOV AL,0xff
OUT PIC1_IMR,AL
CLI
;A20GATE ON
CALL waitKBCReady ;KBC
MOV AL,CMD_KBC_WRITE_OUTREGISTER
OUT REGISTER_KBC_CMD,AL
CALL waitKBCReady
MOV AL,CMD_KBC_OUTREGISTER_A20G_ENABLE
OUT REGISTER_KBC_DATA,AL ;A20GATE
CALL waitKBCReady
;protect mode
LGDT [GDTR0]
MOV EAX,CR0
AND EAX,0x7fffffff
OR EAX,0x00000001
MOV CR0,EAX
JMP pipelineflush
pipelineflush:
MOV AX,1*8
MOV DS,AX
MOV ES,AX
MOV SS,AX
MOV GS,AX
MOV FS,AX
;0x280000 pio lba28
MOV AL,150
MOV ECX,150
SHL ECX,8
MOV DX,0x01f2
OUT DX,AL
MOV AX,BOOTPACK_SEC
;0~7
MOV DX,0x01f3
OUT DX,AL
;8~15
SHR AX,8
MOV DX,0x01f4
OUT DX,AL
;16~23
XOR AL,AL
MOV DX,0x01f5
OUT DX,AL
;24~27，4：0，5：1，6：1（LBA），7：1
MOV AL,0xe0
MOV DX,0x01f6
OUT DX,AL
MOV AL,0x20
MOV DX,0x01f7
OUT DX,AL
.waitHDReady:
IN AL,DX
AND AL,0x88
CMP AL,0x08
JNE .waitHDReady
MOV DX,0x01f0
MOV EBX,BOOTPAK_ADR ;0x280000
.read_word:
IN AX,DX
MOV WORD [EBX],AX
ADD EBX,2
DEC ECX
JNZ .read_word
;copy data section
MOV EAX,BOOTPAK_ADR ;0x280000
MOV EDX,[EAX+16] ;data section bytes count
ADD EDX,3
SHR EDX,2 ;double words count
JZ Go
MOV EBX,[EAX+20] ;data section start byte address
ADD EBX,BOOTPAK_ADR
MOV ECX,[EAX+12] ;esp
CALL memcpy
Go:
MOV EAX,BOOTPAK_ADR
MOV ESP,DWORD [EAX+12]
MOV DWORD [SYS_ESP],ESP
JMP DWORD 2*8:0x0000001b ;far jump
waitKBCReady:
IN AL,REGISTER_KBC_STA
AND AL,0x02
JNZ waitKBCReady
RET
memcpy: ; EBX:source address，ECX：destination, EDX:double words count
MOV EAX,DWORD [EBX]
MOV DWORD [ECX],EAX
ADD EBX,4
ADD ECX,4
SUB EDX,1
JNZ memcpy
RET
ALIGNB 16
GDT0: ;GDT
RESB 8
DB 0xff,0xff,0x00,0x00,0x00,0x92,0xcf,0x00 ;set_segmdesc(gdt + 1, 0xffffffff, 0x00000000, 0x4092);
DW 0xffff,0x0000,0x9a28,0x0047 ;set_segmdesc(gdt + 2, 0x0007ffff, 0x00280000, 0x409a);
DW 0
GDTR0: ;GDTR
DW 8*3-1
DD GDT0
ALIGNB 16
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qemu-system-x86_64.exe -name test -L . -m 1024 -hda haribHD.img -boot c