payloads/libpayload/drivers/video/vga.c

   1 /*
   2  *
   3  * Copyright (C) 2008 Advanced Micro Devices, Inc.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <libpayload.h>
  30 #include <video_console.h>
  31
  32 struct video_console vga_video_console;
  33
  34 #define VGA_COLOR_WHITE 7
  35
  36 #define CRTC_INDEX      0x3d4
  37 #define CRTC_DATA       0x3d5
  38
  39 #define VIDEO(_r, _c)\
  40   ((u16 *) (phys_to_virt(0xB8000) + ((_r) * (vga_video_console.columns * 2)) + ((_c) * 2)))
  41
  42 static u8 crtc_read(u8 index)
  43 {
  44         outb(index, CRTC_INDEX);
  45         return inb(CRTC_DATA);
  46 }
  47
  48 static void crtc_write(u8 data, u8 index)
  49 {
  50         outb(index, CRTC_INDEX);
  51         outb(data, CRTC_DATA);
  52 }
  53
  54 static void vga_get_cursor(unsigned int *x, unsigned int *y, unsigned int *en)
  55 {
  56         unsigned int addr;
  57         addr = ((unsigned int) crtc_read(0x0E)) << 8;
  58         addr += crtc_read(0x0F);
  59
  60         *x = addr % vga_video_console.columns;
  61         *y = addr / vga_video_console.columns;
  62
  63         *en = !(crtc_read(0x0A) & (1 << 5));
  64 }
  65
  66 static void vga_set_cursor(unsigned int x, unsigned int y)
  67 {
  68         unsigned int addr;
  69
  70         addr = x + (vga_video_console.columns * y);
  71         crtc_write(addr >> 8, 0x0E);
  72         crtc_write(addr, 0x0F);
  73 }
  74
  75 static void vga_enable_cursor(int state)
  76 {
  77         unsigned char tmp = crtc_read(0x0a);
  78
  79         if (state == 0)
  80                 tmp |= (1 << 5);
  81
  82         else
  83                 tmp &= ~(1 << 5);
  84
  85         crtc_write(tmp, 0x0a);
  86 }
  87
  88 static void vga_clear_line(u8 row, u8 ch, u8 attr)
  89 {
  90         int col;
  91         u16 *ptr = VIDEO(row, 0);
  92
  93         for(col = 0; col < vga_video_console.columns; col++)
  94                 ptr[col] = ((attr & 0xFF) << 8) | (ch & 0xFF);
  95 }
  96
  97 static void vga_scroll_up(void)
  98 {
  99         u16 *src = VIDEO(1,0);
 100         u16 *dst = VIDEO(0,0);
 101         int i;
 102
 103         for(i = 0; i < (vga_video_console.rows - 1) * vga_video_console.columns; i++)
 104                 *dst++ = *src++;
 105
 106         vga_clear_line(vga_video_console.rows - 1, ' ', VGA_COLOR_WHITE);
 107 }
 108
 109 static void vga_fill(u8 ch, u8 attr)
 110 {
 111         u8 row;
 112         for(row = 0; row < vga_video_console.rows; row++)
 113                 vga_clear_line(row, ch, attr);
 114 }
 115
 116 static void vga_clear(void)
 117 {
 118         vga_fill(' ', VGA_COLOR_WHITE);
 119 }
 120
 121 static void vga_putc(u8 row, u8 col, unsigned int c)
 122 {
 123         u16 *ptr = VIDEO(row, col);
 124         *ptr = (u16) (c & 0xFFFF);
 125 }
 126
 127 static void vga_init_cursor(void)
 128 {
 129         u8 val;
 130
 131 #define CURSOR_MSL   0x09   /* cursor maximum scan line */
 132 #define CURSOR_START 0x0A   /* cursor start */
 133 #define CURSOR_END   0x0B   /* cursor end */
 134
 135         val = crtc_read(CURSOR_MSL) & 0x1f;
 136         crtc_write(0, CURSOR_START);
 137         crtc_write(val - 2, CURSOR_END);
 138 }
 139
 140 static int vga_init(void)
 141 {
 142         vga_init_cursor();
 143         return 0;
 144 }
 145
 146 struct video_console vga_video_console = {
 147         .init = vga_init,
 148         .putc = vga_putc,
 149         .clear = vga_clear,
 150         .scroll_up = vga_scroll_up,
 151
 152         .get_cursor = vga_get_cursor,
 153         .set_cursor = vga_set_cursor,
 154         .enable_cursor = vga_enable_cursor,
 155
 156         .columns = 80,
 157         .rows    = 25
 158 };