93 lines
1.5 KiB
NASM
93 lines
1.5 KiB
NASM
[BITS 16]
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real_hexprint:
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xor cx, cx
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mov bl, al
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shr al, 4
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jmp .donibble
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.nibble2:
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mov al, bl
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inc cx
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.donibble:
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and al, 0x0F
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cmp al, 0x0A
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jl .noadjust
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add al, 'A' - '0' - 10
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.noadjust:
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add al, '0'
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mov ah, 0x1f
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stosw
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test cx, cx
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jz .nibble2
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ret
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real_printword:
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mov dx, ax
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mov al, ah
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call real_hexprint
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mov ax, dx
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call real_hexprint
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ret
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global v86Test
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v86Test:
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mov ax, 0xb814
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mov es, ax
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mov di, 20
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mov ax, sp
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call real_printword
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add di, 2
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mov ax, ds
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call real_printword
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add di, 2
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mov ax, cs
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call real_printword
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.loop:
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inc byte [0]
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int 3
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int 3
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int 0x30 ; exit
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jmp $
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global v86GfxMode
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v86GfxMode:
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mov ax, 0x13
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int 0x10
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int 0x30
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jmp $
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global v86TextMode
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v86TextMode:
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mov ax, 0x3
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int 0x10
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int 0x30
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jmp $
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global v86DiskRead
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v86DiskRead:
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xor ax, ax ; TODO fix assuming we're in first 64k
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mov ds, ax
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mov ah, 0x42
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mov dl, 0x80 ; TODO get this from BIOS or something
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mov si, v86disk_addr_packet ; ds:si
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int 0x13
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int 0x30
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jmp $
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v86disk_addr_packet:
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db 0x10, 0x00 ; size, reserved
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dw 0x20 ; blocks
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dd 0x23000000 ; transfer buffer 0x23000
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dq 0 ; start block
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[BITS 32]
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; extern void enter_v86(uint32_t ss, uint32_t esp, uint32_t cs, uint32_t eip);
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global enter_v86
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enter_v86:
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pop eax
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mov ebp, esp ; save stack pointer
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call save_current_task
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push dword [ebp+0] ; ss
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push dword [ebp+4] ; esp
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pushfd ; eflags
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or dword [esp], (1 << 17) ; set VM flags
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;or dword [esp], (3 << 12) ; IOPL 3
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push dword [ebp+8] ; cs
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push dword [ebp+12] ; eip
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iret
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; return address in eax, return stack in ebp
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extern save_current_task
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