forked from offtopia/ponydos
157 lines
2 KiB
NASM
157 lines
2 KiB
NASM
cpu 8086
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bits 16
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org 0x7c00
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mouse_packet equ 0x500
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jmp 0:start
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start:
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cld
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cli
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; Set up segments and stack
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mov ax, cs
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mov ds, ax
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mov es, ax
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mov ss, ax
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mov sp, $$
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; Hook up IRQ12
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mov [0x01D0], word mouse_irq
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mov [0x01D0 + 2], word 0
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sti
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init_8042:
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; TODO: This does not make sure the input buffer has been emptied
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; before writing to it. Works fine in QEMU, but may fail on
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; real hardware.
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; Disable devices
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mov al, 0xad
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out 0x64, al
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mov al, 0xa7
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out 0x64, al
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; Flush output buffer
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in al, 0x60
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; Get controller config byte
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mov al, 0x20
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out 0x64, al
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.wait_config:
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in al, 0x64
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test al, 1<<0 ; Test whether output status buffer has data
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jz .wait_config
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in al, 0x60
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; Enable second PS/2 device (likely mouse) interrupt
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or al, 1<<1
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mov bl, al
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mov al, 0x60
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out 0x64, al
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mov al, bl
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out 0x60, al
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; Enable devices
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mov al, 0xae
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out 0x64, al
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mov al, 0xa8
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out 0x64, al
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init_mouse:
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; Start packet streaming
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mov al, 0xd4
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out 0x64, al
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mov al, 0xf4
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out 0x60, al
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mainloop:
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; TODO: everything
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hang:
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hlt
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jmp hang
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mouse_irq:
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push ax
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push bx
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; Read mouse data
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in al, 0x60
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xor bh, bh
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mov bl, [mouse_packet_fill]
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test bl, bl
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jnz .store_byte
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test al, 1<<3 ; Always-on bit in first byte
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jz .finish
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.store_byte:
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mov [mouse_packet + bx], al
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inc bl
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cmp bl, 3
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jne .finish
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.full_packet:
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; TODO: Do something useful with the mouse packet
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push si
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mov si, mouse_packet
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lodsb
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call hexprint8
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lodsb
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call hexprint8
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lodsb
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call hexprint8
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pop si
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mov ax, 0x0e20
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int 0x10
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; Empty out the mouse packet buffer
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xor bl, bl
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.finish:
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; Store back possibly updated mouse packet fill
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mov [mouse_packet_fill], bl
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; Reset PICs
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mov al, 0x20
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out 0xa0, al
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out 0x20, al
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pop bx
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pop ax
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iret
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hexprint8:
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push ax
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push cx
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mov cl, 4
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shr al, cl
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call hexprint4
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pop cx
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pop ax
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hexprint4:
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push ax
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and al, 0xf
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cmp al, 10
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jb .digit09
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add al, 'a' - '0' - 10
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.digit09:
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add al, '0'
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mov ah, 0x0e
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int 0x10
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pop ax
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ret
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mouse_packet_fill db 0
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times 510-($-$$) db 0
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db 0x55
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db 0xaa
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