LXR coreboot/payloads/libpayload/drivers/video/vga.c

   1/*
   2 * This file is part of the libpayload project.
   3 *
   4 * Copyright (C) 2008 Advanced Micro Devices, Inc.
   5 *
   6 * Redistribution and use in source and binary forms, with or without
   7 * modification, are permitted provided that the following conditions
   8 * are met:
   9 * 1. Redistributions of source code must retain the above copyright
  10 *    notice, this list of conditions and the following disclaimer.
  11 * 2. Redistributions in binary form must reproduce the above copyright
  12 *    notice, this list of conditions and the following disclaimer in the
  13 *    documentation and/or other materials provided with the distribution.
  14 * 3. The name of the author may not be used to endorse or promote products
  15 *    derived from this software without specific prior written permission.
  16 *
  17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27 * SUCH DAMAGE.
  28 */
  29
  30#include <libpayload.h>
  31#include <video_console.h>
  32
  33struct video_console vga_video_console;
  34
  35#define VGA_COLOR_WHITE 7
  36
  37#define CRTC_INDEX      0x3d4
  38#define CRTC_DATA       0x3d5
  39
  40#define VIDEO(_r, _c)\
  41  ((u16 *) (phys_to_virt(0xB8000) + ((_r) * (vga_video_console.columns * 2)) + ((_c) * 2)))
  42
  43static u8 crtc_read(u8 index)
  44{
  45        outb(index, CRTC_INDEX);
  46        return inb(CRTC_DATA);
  47}
  48
  49static void crtc_write(u8 data, u8 index)
  50{
  51        outb(index, CRTC_INDEX);
  52        outb(data, CRTC_DATA);
  53}
  54
  55static void vga_get_cursor(unsigned int *x, unsigned int *y, unsigned int *en)
  56{
  57        unsigned int addr;
  58        addr = ((unsigned int) crtc_read(0x0E)) << 8;
  59        addr += crtc_read(0x0F);
  60
  61        *x = addr % vga_video_console.columns;
  62        *y = addr / vga_video_console.columns;
  63
  64        *en = !(crtc_read(0x0A) & (1 << 5));
  65}
  66
  67static void vga_set_cursor(unsigned int x, unsigned int y)
  68{
  69        unsigned int addr;
  70
  71        addr = x + (vga_video_console.columns * y);
  72        crtc_write(addr >> 8, 0x0E);
  73        crtc_write(addr, 0x0F);
  74}
  75
  76static void vga_enable_cursor(int state)
  77{
  78        unsigned char tmp = crtc_read(0x0a);
  79
  80        if (state == 0)
  81                tmp |= (1 << 5);
  82
  83        else
  84                tmp &= ~(1 << 5);
  85
  86        crtc_write(tmp, 0x0a);
  87}
  88
  89static void vga_clear_line(u8 row, u8 ch, u8 attr)
  90{
  91        int col;
  92        u16 *ptr = VIDEO(row, 0);
  93
  94        for(col = 0; col < vga_video_console.columns; col++)
  95                ptr[col] = ((attr & 0xFF) << 8) | (ch & 0xFF);
  96}
  97
  98static void vga_scroll_up(void)
  99{
 100        u16 *src = VIDEO(1,0);
 101        u16 *dst = VIDEO(0,0);
 102        int i;
 103
 104        for(i = 0; i < (vga_video_console.rows - 1) * vga_video_console.columns; i++)
 105                *dst++ = *src++;
 106
 107        vga_clear_line(vga_video_console.rows - 1, ' ', VGA_COLOR_WHITE);
 108}
 109
 110static void vga_fill(u8 ch, u8 attr)
 111{
 112        u8 row;
 113        for(row = 0; row < vga_video_console.rows; row++)
 114                vga_clear_line(row, ch, attr);
 115}
 116
 117static void vga_clear(void)
 118{
 119        vga_fill(' ', VGA_COLOR_WHITE);
 120}
 121
 122static void vga_putc(u8 row, u8 col, unsigned int c)
 123{
 124        u16 *ptr = VIDEO(row, col);
 125        *ptr = (u16) (c & 0xFFFF);
 126}
 127
 128static void vga_init_cursor(void)
 129{
 130        u8 val;
 131
 132#define CURSOR_MSL   0x09   /* cursor maximum scan line */
 133#define CURSOR_START 0x0A   /* cursor start */
 134#define CURSOR_END   0x0B   /* cursor end */
 135
 136        val = crtc_read(CURSOR_MSL) & 0x1f;
 137        crtc_write(0, CURSOR_START);
 138        crtc_write(val - 2, CURSOR_END);
 139}
 140
 141static int vga_init(void)
 142{
 143        vga_init_cursor();
 144        return 0;
 145}
 146
 147struct video_console vga_video_console = {
 148        .init = vga_init,
 149        .putc = vga_putc,
 150        .clear = vga_clear,
 151        .scroll_up = vga_scroll_up,
 152
 153        .get_cursor = vga_get_cursor,
 154        .set_cursor = vga_set_cursor,
 155        .enable_cursor = vga_enable_cursor,
 156
 157        .columns = 80,
 158        .rows    = 25
 159};
 160