vga-logic-processor-examples/vga.asm

370 lines
5.7 KiB
NASM

PUBLIC _enableUnchainedVGAMode
PUBLIC _enableTextMode
PUBLIC _fillScreen
PUBLIC _latchCopyCube
PUBLIC _drawColorCube
PUBLIC _writeCube
PUBLIC _paramTest
PUBLIC _keyboardPressed
PUBLIC keyboardHandler_
DISPLAY_MODE_VGA equ 13h
DISPLAY_MODE_TEXT equ 03h
VGA_SEQUENCE_CONTROLLER_INDEX equ 0x3c4
VGA_SEQUENCE_CONTROLLER_DATA equ 0x3c5
VGA_SEQUENCE_CONTROLLER_MEMORY_MODE equ 0x04
VGA_SEQUENCE_CONTROLLER_MAP_MASK_MODE equ 0x02
VGA_GRAPHICS_MODE_INDEX equ 0x3CE
VGA_GRAPHICS_MODE equ 0x05
VGA_CRT_CONTROLLER_INDEX equ 0x03d4
VGA_CRT_CONTROLLER_DATA equ 0x03d5
VGA_CRT_CONTROLLER_UNDERLINE_LOC equ 0x14
VGA_CRT_CONTROLLER_MODE_CONTROL equ 0x17
.386
.model flat,c
.DATA
_keyboardPressed db 0
.CODE
keyboardHandler_:
cli
push eax
push ebx
in al, 0x60
mov bl, al
; acknowledge keyboard
in al, 0x61
mov ah, al
or al, 0x80
out 0x61, al
xchg ah, al
out 0x61, al
and bl,0x80
jne _keyboardHandler_notKeydown
mov [_keyboardPressed], 1
_keyboardHandler_notKeydown:
; acknowledge interrupt
mov al, 0x20
out 0x20, al
pop ebx
pop eax
sti
iretd
_enableUnchainedVGAMode:
mov ax,0x0013;
int 0x10
mov dx, VGA_SEQUENCE_CONTROLLER_INDEX
mov al, VGA_SEQUENCE_CONTROLLER_MEMORY_MODE
mov ah, 0x06
out dx, ax
mov dx, VGA_CRT_CONTROLLER_INDEX
mov al, VGA_CRT_CONTROLLER_MODE_CONTROL
mov ah, 0xe3
out dx, ax
mov dx, VGA_CRT_CONTROLLER_INDEX
mov al, VGA_CRT_CONTROLLER_UNDERLINE_LOC
mov ah, 0x00
out dx, ax
ret
_enableTextMode:
mov ah,0h
mov al,DISPLAY_MODE_TEXT
int 10h
ret
_fillScreen:
push ebp
mov ebp, esp
; set all bitplanes
mov dx, VGA_SEQUENCE_CONTROLLER_INDEX
mov al, 0x02
mov ah, 0fh
out dx, ax
mov al, [ebp+8] ; requested color
mov cx, 16000 ; loop index
mov ebx, 0xa0000
_fillScreen_loop:
mov BYTE PTR [ebx], al
inc ebx
loop _fillScreen_loop
mov esp,ebp
pop ebp
ret
_paramTest:
push ebp
mov ebp,esp
mov eax,0
mov al, BYTE PTR [ebp+8]
mov esp,ebp
pop ebp
ret
_drawColorCube:
push ebp
mov ebp, esp
sub esp, 4 ; y
push ebx
push ecx
push edx
; write to all planes
mov dx, VGA_SEQUENCE_CONTROLLER_INDEX
mov al, VGA_SEQUENCE_CONTROLLER_MAP_MASK_MODE
mov ah, 0xf
out dx, ax
; write out host data only
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x03
mov ah, 0x00
out dx, ax
; disable set/reset registers
mov al, 0x00
mov ah, 0x00
out dx, ax
mov al, 0x01
mov ah, 0x00
out dx, ax
mov DWORD PTR [ebp-4], 16 ; y
mov cx,[ebp-4]
; offset is [ebp+8]
mov bh,[ebp+12]; color
_drawColorCube_yLoop:
mov [ebp-4],cx
mov eax,[ebp-4]
dec eax
mov bl,80
mul bl
add eax,[ebp+8]
add eax,0xa0000
mov cx, 4
_drawColorCube_xLoop:
mov [eax],bh ; write color
inc eax
loop _drawColorCube_xLoop
mov cx, [ebp-4]
loop _drawColorCube_yLoop
pop edx
pop ecx
pop ebx
mov esp, ebp
pop ebp
ret
_writeCube:
push ebp
mov ebp,esp
; we need a y variable
sub esp,4
; and a current color
sub esp,4
; [ebp+8] is x offset
; [ebp+12] is data rotate
; [ebp+16] is set/reset
; [ebp+20] is enable set/reset
; enable Logical Operation and host data shifts
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x03
mov ah, [ebp+12]
out dx, ax
; enable set/reset registers
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x00
mov ah, [ebp+16]
out dx, ax
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x01
mov ah, [ebp+20]
out dx, ax
mov DWORD PTR [ebp-8],0
mov DWORD PTR [ebp-4],16
mov cx,[ebp-4]
_writeCube_yLoop:
mov [ebp-4],cx
mov eax,[ebp-4]
dec eax
mov bl,80
mul bl
add eax,0xa0000
mov cx,16
_writeCube_xLoop:
; get the current plane
push ecx
dec cl
and cl,0x03
jne _writeCube_dontAdvanceVGA
inc eax
_writeCube_dontAdvanceVGA:
mov bl,1
sal bl,cl
pop ecx
push eax
; write to one plane
mov dx, VGA_SEQUENCE_CONTROLLER_INDEX
mov al, VGA_SEQUENCE_CONTROLLER_MAP_MASK_MODE
mov ah, bl
out dx, ax
pop eax
;mov ebx,[ebp+8]
push ecx
mov ecx,[ebp+8]
mov bl,[ebp-8]
mov BYTE PTR [eax+ecx],bl
inc bl
mov [ebp-8],bl
pop ecx
loop _writeCube_xLoop
mov cx,[ebp-4]
loop _writeCube_yLoop
mov esp,ebp
pop ebp
ret
_latchCopyCube:
push ebp
mov ebp, esp
; we need a y variable
sub esp,4 ; y
push edx
push ebx
; accept a mode
; accept a mix value
; accept an x offset
; [ebp+8] is x offset
; [ebp+12] is written value
; [ebp+16] is data rotate register
; [ebp+20] is set/reset register
; [ebp+24] is enable set/reset register
; write to all planes
mov dx, VGA_SEQUENCE_CONTROLLER_INDEX
mov al, VGA_SEQUENCE_CONTROLLER_MAP_MASK_MODE
mov ah, 0xf
out dx, ax
; enable Logical Operation and host data shifts
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x03
mov ah, [ebp+16]
out dx, ax
; enable set/reset registers
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x00
mov ah, [ebp+20]
out dx, ax
mov dx, VGA_GRAPHICS_MODE_INDEX
mov al, 0x01
mov ah, [ebp+24]
out dx, ax
mov dh, [ebp+12]
mov DWORD PTR [ebp-4],16 ; y
; read across the cube, should take 4 * 16 reads
mov cx,[ebp-4]
_latchCopyCube_yLoop:
mov [ebp-4],cx ; put y back in loop
mov eax,[ebp-4] ; put y in eax
dec eax ; offset by 1 for loop
; can only multiply in eax by register
mov bl,80
mul bl ; number of lines
add eax,0xa0000 ; vga base address
; keep our index handy
mov ebx, [ebp+8]
; start x loop
mov cx,4
_latchCopyCube_xLoop:
; fill latches via memory read
mov dl, BYTE PTR [eax]
; write blank
mov BYTE PTR [eax+ebx], dh
; increment vga pointer
inc eax
; loop until x is 0
loop _latchCopyCube_xLoop
; restore y for looping
mov cx,[ebp-4]
; loop until y is 0
loop _latchCopyCube_yLoop
; put things back
pop ebx
pop edx
mov esp,ebp
pop ebp
ret
end