vga_utils.asm

一个类似与Windows环境下的softice的源代码

;****************************************************************************
section .text
pice_set_graphic_registers:
			xor	dword ecx, ecx
.loop:			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, cl
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			mov	byte  al, [ebx + ecx]
			out	word  dx, al
			inc	dword ecx
			cmp	dword ecx, VGA_GRAPHIC_REGISTERS
			jb	.loop
			ret



;****************************************************************************
;* pice_set_sequencer_registers ********************************************
;****************************************************************************
;* ebx=>  pointer to stored sequencer registers
;****************************************************************************
section .text
pice_set_sequencer_registers:

			;synchronous reset on

			mov	dword edx, VGA_SEQUENCER_INDEX
			xor	dword eax, eax
			out	word  dx, al
			mov	dword edx, VGA_SEQUENCER_DATA
			inc	dword eax
			out	word  dx, al

			;write to the registers

			mov	dword edx, VGA_SEQUENCER_INDEX
			out	word  dx, al
			mov	dword edx, VGA_SEQUENCER_DATA
			mov	byte  al, [ebx + 1]
			or	byte  al, 020h
			out	word  dx, al
			mov	dword ecx, 2
.loop:			mov	dword edx, VGA_SEQUENCER_INDEX
			mov	byte  al, cl
			out	word  dx, al
			mov	dword edx, VGA_SEQUENCER_DATA
			mov	byte  al, [ebx + ecx]
			out	word  dx, al
			inc	dword ecx
			cmp	dword ecx, VGA_SEQUENCER_REGISTERS
			jb	.loop

			;synchronous reset off

			mov	dword edx, VGA_SEQUENCER_INDEX
			xor	dword eax, eax
			out	word  dx, al
			mov	dword edx, VGA_SEQUENCER_DATA
			mov	byte  al, 3
			out	word  dx, al
			ret



;****************************************************************************
;* pice_set_misc_registers *************************************************
;****************************************************************************
;* ebx=>  pointer to stored misc register
;****************************************************************************
section .text
pice_set_misc_registers:
			mov	dword edx, VGA_MISC_DATA_WRITE
			mov	byte  al, [ebx]
			out	word dx, al
			ret



;****************************************************************************
;* pice_set_colormap *******************************************************
;****************************************************************************
;* ebx=>  pointer to stored colormap
;****************************************************************************
section .text
pice_set_colormap:
			xor	dword ecx, ecx
			xor	dword eax, eax
			mov	dword edx, VGA_PEL_INDEX_WRITE
			out	word  dx, al
			mov	dword edx, VGA_PEL_DATA
.loop:			mov	dword eax, [ebx + 4 * ecx]
			rol	dword eax, 16
			out	word  dx, al
			rol	dword eax, 8
			out	word  dx, al
			rol	dword eax, 8
			out	word  dx, al
			inc	dword ecx
			test	byte  cl, cl
			jnz	.loop
			ret



;****************************************************************************
;* pice_screen_on **********************************************************
;****************************************************************************
section .text
pice_screen_on:

			;turn on the screen

			mov	dword edx, VGA_SEQUENCER_INDEX
			mov	byte  al, 1
			out	word  dx, al
			mov	dword edx, VGA_SEQUENCER_DATA
			in	byte  al, dx
			and	byte  al, 0dfh
			out	word  dx, al

			;enable video output

			mov	dword edx, VGA_INPUT_STATUS
			in	byte  al, dx
			mov	dword edx, VGA_ATTRIBUTE_DATA_WRITE
			mov	byte  al, 020h
			out	word  dx, al
			ret

;****************************************************************************
;* pice_select_write_plane *************************************************
;****************************************************************************
;* bl==>  write mode
;* bh==>  write plane
;****************************************************************************
section .text
pice_select_write_plane:
			and	dword ebx, 00f03h

			;enable set/reset = 0

			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, 1
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			xor	dword eax, eax
			out	word  dx, al

			;logical operation = none, rotate = 0

			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, 3
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			xor	dword eax, eax
			out	word  dx, al

			;select write mode

			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, 5
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			in	byte  al, dx
			and	byte  al, 0fch
			or	byte  al, bl
			out	word  dx, al

			;bitmask = 0ffh

			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, 8
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			mov	byte  al, 0ffh
			out	word  dx, al

			;select write plane

			mov	dword edx, VGA_SEQUENCER_INDEX
			mov	byte  al, 2
			out	word  dx, al
			mov	dword edx, VGA_SEQUENCER_DATA
			mov	byte  al, bh
			out	word  dx, al
			ret



;****************************************************************************
;* pice_select_read_plane **************************************************
;****************************************************************************
;* bl==>  read mode
;* bh==>  read plane
;****************************************************************************
section .text
pice_select_read_plane:
			and	dword ebx, 00301h
			shl	byte  bl, 3

			;select read mode

			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, 5
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			in	byte  al, dx
			and	byte  al, 0f7h
			or	byte  al, bl
			out	word  dx, al

			;select read plane

			mov	dword edx, VGA_GRAPHIC_INDEX
			mov	byte  al, 4
			out	word  dx, al
			mov	dword edx, VGA_GRAPHIC_DATA
			mov	byte  al, bh
			out	word  dx, al
			ret



;****************************************************************************
;* pice_save_current_registers **********************************************
;****************************************************************************
section .text
pice_save_current_registers:
			push esi
			push edi
			push ebx

;			call	pice_save_current_charset

.crt:		mov	dword ebx, pice_current_registers.crt
			call	pice_get_crt_registers

.attribute:	mov	dword ebx, pice_current_registers.attribute
			call	pice_get_attribute_registers

.graphic:	mov	dword ebx, pice_current_registers.graphic
			call	pice_get_graphic_registers

.sequencer:	mov	dword ebx, pice_current_registers.sequencer
			call	pice_get_sequencer_registers

.misc:		mov	dword ebx, pice_current_registers.misc
			call	pice_get_misc_registers

.colormap:	mov	dword ebx, pice_current_registers.colormap
			call	pice_get_colormap

			pop ebx
			pop edi
			pop esi
.end:		ret

;****************************************************************************
;* pice_restore_current_registers *******************************************
;****************************************************************************
section .text
pice_restore_current_registers:
			push esi
			push edi
			push ebx

;			call	pice_restore_current_charset

.misc:		mov	dword ebx, pice_current_registers.misc
			call	pice_set_misc_registers

.crt:		mov	dword ebx, pice_current_registers.crt
			call	pice_set_crt_registers

.attribute:	mov	dword ebx, pice_current_registers.attribute
			call	pice_set_attribute_registers

.graphic:	mov	dword ebx, pice_current_registers.graphic
			call	pice_set_graphic_registers

.sequencer:	mov	dword ebx, pice_current_registers.sequencer
			call	pice_set_sequencer_registers

.screen_on:	call	pice_screen_on

.colormap:	mov	dword ebx, pice_current_registers.colormap
			call	pice_set_colormap

			pop ebx
			pop edi
			pop esi

.end:		ret


;****************************************************************************
;* pice_set_mode_3_80x50*****************************************************
;****************************************************************************
section .text
pice_set_mode_3_80x50:
			push esi
			push edi
			push ebx

.crt:		mov	dword ebx, pice_mode3_80x50_registers.crt
			call	pice_set_crt_registers

.attribute:	mov	dword ebx, pice_mode3_80x50_registers.attribute
			call	pice_set_attribute_registers

.graphic:	mov	dword ebx, pice_mode3_80x50_registers.graphic
			call	pice_set_graphic_registers

.sequencer:	mov	dword ebx, pice_mode3_80x50_registers.sequencer
			call	pice_set_sequencer_registers

.misc:		mov	dword ebx, pice_mode3_80x50_registers.misc
			call	pice_set_misc_registers

.screen_on:	call	pice_screen_on

;.colormap:	mov	dword ebx, pice_current_registers.colormap
;			call	pice_set_colormap

			pop ebx
			pop edi
			pop esi

.end:		ret

;****************************************************************************
;* pice_set_mode_3_80x25*****************************************************
;****************************************************************************
section .text
pice_set_mode_3_80x25:
			push esi
			push edi
			push ebx

.crt:		mov	dword ebx, pice_mode3_80x25_registers.crt
			call	pice_set_crt_registers

.attribute:	mov	dword ebx, pice_mode3_80x25_registers.attribute
			call	pice_set_attribute_registers

.graphic:	mov	dword ebx, pice_mode3_80x25_registers.graphic
			call	pice_set_graphic_registers

.sequencer:	mov	dword ebx, pice_mode3_80x25_registers.sequencer
			call	pice_set_sequencer_registers

.misc:		mov	dword ebx, pice_mode3_80x25_registers.misc
			call	pice_set_misc_registers

.screen_on:	call	pice_screen_on

;.colormap:	mov	dword ebx, pice_current_registers.colormap
;			call	pice_set_colormap

			pop ebx
			pop edi
			pop esi

.end:		ret

;****************************************************************************
;* uninitialized data *******************************************************
;****************************************************************************
section .bss
			alignb	4
pice_charset_saved:	resb	040000h