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Diffstat (limited to 'payloads/libpayload/drivers/vga.c')
| -rw-r--r-- | payloads/libpayload/drivers/vga.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/payloads/libpayload/drivers/vga.c b/payloads/libpayload/drivers/vga.c new file mode 100644 index 0000000000..5e0e406f27 --- /dev/null +++ b/payloads/libpayload/drivers/vga.c @@ -0,0 +1,216 @@ +/* + * This file is part of the libpayload project. + * + * Copyright (C) 2008 Advanced Micro Devices, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <arch/types.h> +#include <libpayload.h> + +#define WIDTH 80 +#define HEIGHT 25 + +#define VGA_COLOR_WHITE 7 + +#define CRTC_INDEX 0x3d4 +#define CRTC_DATA 0x3d5 + +#define VIDEO(_r, _c)\ + ((uint16_t *) (0xB8000 + ((_r) * (WIDTH * 2)) + ((_c) * 2))) + +static int cursor_enabled; +static int cursorx; +static int cursory; + +static void vga_scroll_up(void); + +static inline uint8_t crtc_read(uint8_t index) +{ + outb(index, CRTC_INDEX); + return inb(CRTC_DATA); +} + +static inline void crtc_write(uint8_t data, uint8_t index) +{ + outb(index, CRTC_INDEX); + outb(data, CRTC_DATA); +} + +static void vga_get_cursor_pos(void) +{ + unsigned int addr; + addr = ((unsigned int) crtc_read(0x0E)) << 8; + addr += crtc_read(0x0E); + + cursorx = addr % WIDTH; + cursory = addr / WIDTH; +} + +static void vga_fixup_cursor(void) +{ + unsigned int addr; + + if (!cursor_enabled) + return; + + if (cursorx < 0) + cursorx = 0; + + if (cursory < 0) + cursory = 0; + + if (cursorx >= WIDTH) { + cursorx = 0; + cursory++; + } + + while(cursory >= HEIGHT) + vga_scroll_up(); + + addr = cursorx + (WIDTH * cursory); + crtc_write(addr >> 8, 0x0E); + crtc_write(addr, 0x0E); +} + +void vga_cursor_enable(int state) +{ + unsigned char tmp = crtc_read(0x0a); + + if (state == 0) { + tmp |= (1 << 5); + cursor_enabled = 0; + } + else { + tmp &= ~(1 << 5); + cursor_enabled = 1; + vga_fixup_cursor(); + } + + crtc_write(tmp, 0x0a); +} + +void vga_clear_line(uint8_t row, uint8_t ch, uint8_t attr) +{ + int col; + uint16_t *ptr = VIDEO(0, row); + + for(col = 0; col < WIDTH; col++) + ptr[col] = ((attr & 0xFF) << 8) | (ch & 0xFF); +} + +static void vga_scroll_up(void) +{ + uint16_t *src = VIDEO(0,1); + uint16_t *dst = VIDEO(0,0); + int i; + + for(i = 0; i < (HEIGHT - 1) * WIDTH; i++) + *dst++ = *src++; + + vga_clear_line(HEIGHT - 1, ' ', VGA_COLOR_WHITE); + cursory--; +} + +void vga_fill(uint8_t ch, uint8_t attr) +{ + uint8_t row; + for(row = 0; row < HEIGHT; row++) + vga_clear_line(row, ch, attr); +} + +void vga_clear(void) +{ + vga_fill(' ', VGA_COLOR_WHITE); + vga_move_cursor(0, 0); +} + +void vga_putc(uint8_t row, uint8_t col, unsigned int c) +{ + uint16_t *ptr = VIDEO(row, col); + *ptr = (uint16_t) (c & 0xFFFF); +} + +void vga_putchar(unsigned int ch) { + + uint16_t *ptr; + + switch(ch & 0xFF) { + case '\r': + cursorx = 0; + break; + case '\n': + cursory++; + break; + case '\b': + cursorx--; + ptr = VIDEO(cursory, cursorx); + *ptr = (*ptr & 0xFF00) | ' '; + break; + case '\t': + cursorx = (cursorx + 8) & ~7; + break; + + default: + ptr = VIDEO(cursory, cursorx); + *ptr = (uint16_t) (ch & 0xFFFF); + cursorx++; + break; + } + + vga_fixup_cursor(); +} + +int vga_move_cursor(int x, int y) +{ + cursorx = x; + cursory = y; + + vga_fixup_cursor(); +} + +void vga_init(void) +{ + /* Get the position of the cursor */ + vga_get_cursor_pos(); + + /* See if it us currently enabled or not */ + cursor_enabled = !(crtc_read(0x0A) & (1 << 5)); + + /* If the cursor is enabled, get us to a sane point */ + + if (cursor_enabled) { + + /* Go to the next line */ + + if (cursorx) { + cursorx = 0; + cursory++; + } + + vga_fixup_cursor(); + } +} + |