diff options
Diffstat (limited to 'console/vga.c')
| -rw-r--r-- | console/vga.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/console/vga.c b/console/vga.c new file mode 100644 index 00000000..9ad9c08c --- /dev/null +++ b/console/vga.c @@ -0,0 +1,189 @@ +/* vga.c - VGA hardware access. + Copyright (C) 2002 Free Software Foundation, Inc. + Written by Marcus Brinkmann. + + This file is part of the GNU Hurd. + + The GNU Hurd is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + The GNU Hurd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */ + +#include <errno.h> +#include <assert.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/io.h> +#include <sys/mman.h> +#include <sys/types.h> + +#include "vga-hw.h" +#include "vga.h" + + +/* The base of the video memory mapping. */ +char *vga_videomem; + +/* Initialize the VGA hardware and set up the permissions and memory + mappings. */ +error_t +vga_init (void) +{ + error_t err; + int fd; + + if (io_perm (VGA_MIN_REG, VGA_MAX_REG - VGA_MIN_REG + 1, 1) < 0) + return errno; + + fd = open ("/dev/mem", O_RDWR); + if (fd < 0) + return errno; + vga_videomem = mmap (0, VGA_VIDEO_MEM_LENGTH, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, VGA_VIDEO_MEM_BASE_ADDR); + err = errno; + close (fd); + if (vga_videomem == (void *) -1) + return err; + return 0; +} + + +/* Release the resources and privileges associated with the VGA + hardware access. */ +void +vga_deinit (void) +{ + io_perm (VGA_MIN_REG, VGA_MAX_REG, 0); + munmap (vga_videomem, VGA_VIDEO_MEM_LENGTH); +} + + +/* Write DATALEN bytes from DATA to the font buffer BUFFER, starting + from glyph INDEX. */ +void +vga_write_font_buffer (int buffer, int index, char *data, size_t datalen) +{ + char saved_seq_map; + char saved_seq_mode; + char saved_gfx_mode; + char saved_gfx_misc; + + int offset = buffer * VGA_FONT_SIZE + index * VGA_FONT_HEIGHT; + assert (offset >= 0 && offset + datalen <= VGA_VIDEO_MEM_LENGTH); + + /* Select plane 2 for sequential writing. */ + outb_p (VGA_SEQ_MAP_ADDR, VGA_SEQ_ADDR_REG); + saved_seq_map = inb_p (VGA_SEQ_DATA_REG); + outb_p (VGA_SEQ_MAP_PLANE2, VGA_SEQ_DATA_REG); + outb_p (VGA_SEQ_MODE_ADDR, VGA_SEQ_ADDR_REG); + saved_seq_mode = inb_p (VGA_SEQ_DATA_REG); + outb_p (VGA_SEQ_MODE_SEQUENTIAL | VGA_SEQ_MODE_EXT | 0x1 /* XXX Why? */, + VGA_SEQ_DATA_REG); + + /* Set write mode 0, but assume that rotate count, enable set/reset, + logical operation and bit mask fields are set to their + `do-not-modify-host-value' default. The misc register is set to + select sequential addressing in text mode. */ + outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG); + saved_gfx_mode = inb_p (VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MODE_WRITE0, VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG); + saved_gfx_misc = inb_p (VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MISC_A0TOAF, VGA_GFX_DATA_REG); + + memcpy (vga_videomem + offset, data, datalen); + + /* Restore sequencer and graphic register values. */ + outb_p (VGA_SEQ_MAP_ADDR, VGA_SEQ_ADDR_REG); + outb_p (saved_seq_map, VGA_SEQ_DATA_REG); + outb_p (VGA_SEQ_MODE_ADDR, VGA_SEQ_ADDR_REG); + outb_p (saved_seq_mode, VGA_SEQ_DATA_REG); + + outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG); + outb_p (saved_gfx_mode, VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG); + outb_p (saved_gfx_misc, VGA_GFX_DATA_REG); +} + + +/* Read DATALEN bytes into DATA from the font buffer BUFFER, starting + from glyph INDEX. */ +void +vga_read_font_buffer (int buffer, int index, char *data, size_t datalen) +{ + char saved_gfx_map; + char saved_gfx_mode; + char saved_gfx_misc; + + int offset = buffer * VGA_FONT_SIZE + index * VGA_FONT_HEIGHT; + assert (offset >= 0 && offset + datalen <= VGA_VIDEO_MEM_LENGTH); + + /* Read sequentially from plane 2. */ + outb_p (VGA_GFX_MAP_ADDR, VGA_GFX_ADDR_REG); + saved_gfx_map = inb_p (VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MAP_PLANE2, VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG); + saved_gfx_mode = inb_p (VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MODE_READ0, VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG); + saved_gfx_misc = inb_p (VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MISC_A0TOBF, VGA_GFX_DATA_REG); + + memcpy (data, vga_videomem + offset, datalen); + + outb_p (VGA_GFX_MAP_ADDR, VGA_GFX_ADDR_REG); + outb_p (saved_gfx_map, VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG); + outb_p (saved_gfx_mode, VGA_GFX_DATA_REG); + outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG); + outb_p (saved_gfx_misc, VGA_GFX_DATA_REG); +} + + +/* Set FONT_BUFFER_SUPP to FONT_BUFFER if the font is small. */ +void +vga_select_font_buffer (int font_buffer, int font_buffer_supp) +{ + char font = ((font_buffer & 6) >> 1) | ((font_buffer & 1) << 4) + | ((font_buffer_supp & 6) << 1) | ((font_buffer_supp & 1) << 5); + + outb_p (VGA_SEQ_FONT_ADDR, VGA_SEQ_ADDR_REG); + outb_p (font, VGA_SEQ_DATA_REG); +} + + +/* Enable (if ON is true) or disable (otherwise) the cursor. Expects + the VGA hardware to be locked. */ +void +vga_display_cursor (int on) +{ + char crs_start; + + outb (VGA_CRT_CURSOR_START, VGA_CRT_ADDR_REG); + crs_start = inb (VGA_CRT_DATA_REG); + if (on) + crs_start &= ~VGA_CRT_CURSOR_DISABLE; + else + crs_start |= VGA_CRT_CURSOR_DISABLE; + outb (crs_start, VGA_CRT_DATA_REG); +} + + +/* Set the cursor position to POS, which is (x_pos + y_pos * width). */ +void +vga_set_cursor (int pos) +{ + outb (VGA_CRT_CURSOR_HIGH, VGA_CRT_ADDR_REG); + outb (pos >> 8, VGA_CRT_DATA_REG); + outb (VGA_CRT_CURSOR_LOW, VGA_CRT_ADDR_REG); + outb (pos && 0xff, VGA_CRT_DATA_REG); +} |