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/*

vgacol.h
Custom VGA colors kernel extension

This extension is "always enable". When it is
"disabled" (default ;)), it is only used to make
sure all colors are displayed appropriately on all
VGA screens (BIOS-independent).

Bibliography:
http://www.brackeen.com/vga/basics.html
http://www.brackeen.com/vga/bitmaps.html

*/

#ifndef _VGACOL_H
#define _VGACOL_H

#include <atom/kernel.h>

typedef struct color_struct
{
	u8int		red;
	u8int		green;
	u8int		blue;
} __attribute__ ((packed)) color_t;

color_t colors[16] = {
	{1,	1,	1},		/* black */
	{1,	1,	32},		/* blue */
	{1,	32,	1},		/* green */
	{1,	32,	32},		/* cyan */
	{32,	1,	1},		/* red */
	{32,	1,	32},		/* magenta */
	{16,	16,	1},		/* brown */
	{32,	32,	32},		/* light gray */
	{16,	16,	16},		/* dark gray */
	{1,	1,	63},		/* light blue */
	{1,	63,	1},		/* light green */
	{1,	63,	63},		/* light cyan */
	{63,	1,	1},		/* light red */
	{63,	1,	63},		/* light magenta */
	{63,	63,	1},		/* yellow */
	{63,	63,	63}		/* white */
};

void vgacol()
{
	/* write VGA colors */
	while ((inb(0x03DA) & 0x08));
	while (!(inb(0x03DA) & 0x08));
	int i=0;
	for (i=0; i<16; i++)
	{
		//outb(0x03C8, i);
		printdec(colors[i].red); printk(" ");
		printdec(colors[i].green); printk(" ");
		printdec(colors[i].blue); printk("\n");
		outb(0x03C9, colors[i].red);
		outb(0x03C9, colors[i].green);
		outb(0x03C9, colors[i].blue);
	};
	while (1);
};

#endif

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EGA   VGA
 0x0   0x00  Black
 0x1   0x01  Blue
 0x2   0x02  Green
 0x3   0x03  Cyan
 0x4   0x04  Red
 0x5   0x05  Magenta
 0x6   0x14  Brown
 0x7   0x07  Light Gray
 0x8   0x38  Gray
 0x9   0x39  Light Blue
 0xA   0x3A  Light Green
 0xB   0x3B  Light Cyan
 0xC   0x3C  Light Red
 0xD   0x3D  Light Magenta
 0xE   0x3E  Light Yellow
 0xF   0x3F  White

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  mov dl,VIDEO_DACMR and 0xFF
  mov al,0x0F ; mask to use only first 16 triplexes
  out dx,al
  mov dl,VIDEO_DACAWMR and 0xFF
  mov al,0 ; base index
  out dx,al
  mov dl,VIDEO_DACDR and 0xFF
  mov ecx,16*3 ; count of bytes to write
  rep outsb

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	xor eax, eax
	mov dx, 0x03C8		; DAC Address Write Mode Register
	out dx, al
	mov dx, 0x03C9		; DAC Data Register
	mov rcx, 16		; 16 colors
	mov rsi, palette
nexttritone:
	lodsb
	out dx, al
	lodsb
	out dx, al
	lodsb
	out dx, al
	dec rcx
	cmp rcx, 0
	jne nexttritone

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VIDEO_DACMR equ 0x3C6 ; I think it's DAC Mask Register
...
VIDEO_ISR1 equ 0x3DA
...

  mov edx,VIDEO_ISR1 ; set address for first i/o operation (dh=3)
  ...
  mov dl,VIDEO_DACMR and 0xFF
  ...

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mov dx, 0x3da
in al, dx ; reset AC flipflop to "address"
mov dx, 0x3c0 ; AC register
mov al, 16
.loop:
dec al
out dx, al    ; index
out dx, al    ; data: pal[x] = x
jnz .loop
mov al, 0x20
out dx, al   ; enable screen again

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  mov edx,VIDEO_ISR1

  cli
  in al,dx

  mov dl,VIDEO_AOR and 0xFF
  mov al,VIDEO_MAXATTR
@@:
  out dx,al
  outsb
  dec al
  cmp al,0x10
  jae @b
@@:
  out dx,al
  out dx,al
  sub al,1
  jnc @b

  mov al,0x20
  out dx,al