core/font.c

   1 /*
   2  * -----------------------------------------------------------------------
   3  *
   4  *   Copyright 1994-2008 H. Peter Anvin - All Rights Reserved
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   9  *   Boston MA 02111-1307, USA; either version 2 of the License, or
  10  *   (at your option) any later version; incorporated herein by reference.
  11  *
  12  * -----------------------------------------------------------------------
  13  *
  14  *
  15  * font.c
  16  *
  17  * VGA font handling code
  18  *
  19  */
  20
  21 #include <sys/io.h>
  22 #include <stdio.h>
  23 #include <fs.h>
  24 #include "bios.h"
  25 #include "core.h"
  26
  27 char fontbuf[8192];
  28 char serial[serial_buf_size];
  29
  30 extern uint16_t VGAFontSize;
  31 extern uint8_t UserFont;
  32
  33 uint16_t GXPixCols = 1;         /* Graphics mode pixel columns */
  34 uint16_t GXPixRows = 1;         /* Graphics mode pixel rows */
  35
  36 /*
  37  * loadfont:    Load a .psf font file and install it onto the VGA console
  38  *              (if we're not on a VGA screen then ignore.)
  39  *
  40  * The .psf font file must alredy be open and getc_file must be set.
  41  */
  42 void loadfont(char *filename)
  43 {
  44         uint16_t height, magic;
  45         uint32_t *di, *si;
  46         FILE *f;
  47         char *p;
  48         int i;
  49
  50         f = fopen(filename, "r");
  51         if (!f)
  52                 return;
  53
  54         p = trackbuf;
  55         /* Read header */
  56         for (i = 0; i < 4; i++) {
  57                 char ch = getc(f);
  58                 if (ch == EOF)
  59                         return;
  60                 *p++ = ch;
  61         }
  62
  63         /* Magic number */
  64         magic = *(uint16_t *)trackbuf;
  65         if (magic != 0x0436)
  66                 return;
  67
  68         /* File mode: font modes 0-5 supported */
  69         if (*(trackbuf) > 5)
  70                 return;
  71
  72         height = *(trackbuf + 3); /* Height of font */
  73
  74         /* VGA minimum/maximum */
  75         if (height < 2 || height > 32)
  76                 return;
  77
  78         /* Load the actual font. Bytes = font height * 256 */
  79         p = trackbuf;
  80         for (i = 0; i < (height << 8); i++) {
  81                 char ch = getc(f);
  82
  83                 if (ch == EOF)
  84                         return;
  85                 *p++ = ch;
  86         }
  87
  88         /* Copy to font buffer */
  89         VGAFontSize = height;
  90         di = (uint32_t *)fontbuf;
  91         si = (uint32_t *)trackbuf;
  92         for (i = 0; i < (height << 6); i++)
  93                 *di++ = *si++;
  94
  95         UserFont = 1;           /* Set font flag */
  96         use_font();
  97 }
  98
  99 /*
 100  * use_font:
 101  *      This routine activates whatever font happens to be in the
 102  *      vgafontbuf, and updates the adjust_screen data.
 103  *      Must be called with CS = DS
 104  */
 105 void use_font(void)
 106 {
 107         com32sys_t ireg, oreg;
 108         uint8_t bytes = VGAFontSize;
 109
 110
 111         /* Nonstandard mode? */
 112         if (UsingVGA & ~0x3)
 113                 vgaclearmode();
 114
 115         memset(&ireg, 0, sizeof(ireg));
 116
 117         ireg.es = SEG(fontbuf);
 118         ireg.ebp.w[0] = OFFS(fontbuf); /* ES:BP -> font */
 119
 120         /* Are we using a user-specified font? */
 121         if (UserFont & 0x1) {
 122                 /* Are we in graphics mode? */
 123                 if (UsingVGA & 0x1) {
 124                         uint8_t rows;
 125
 126                         rows = GXPixRows / bytes;
 127                         VidRows = rows - 1;
 128
 129                         /* Set user character table */
 130                         ireg.eax.w[0] = 0x1121;
 131                         ireg.ebx.b[0] = 0;
 132                         ireg.ecx.b[0] = bytes; /* bytes/character */
 133                         ireg.edx.b[0] = rows;
 134
 135                         __intcall(0x10, &ireg, &oreg);
 136
 137                         /* 8 pixels/character */
 138                         VidCols = ((GXPixCols >> 3) - 1);
 139
 140                         /* No need to call adjust_screen */
 141                         return;
 142                 } else {
 143                         ireg.eax.w[0] = 0x1110; /* Load into VGA RAM */
 144                         ireg.ebx.b[0] = 0;
 145                         ireg.ebx.b[1] = bytes; /* bytes/character */
 146                         ireg.ecx.w[0] = 256;
 147                         ireg.edx.w[0] = 0;
 148
 149                         __intcall(0x10, &ireg, &oreg);
 150
 151                         ireg.ebx.b[0] = 0;
 152                         ireg.eax.w[0] = 0x1103; /* Select page 0 */
 153                         __intcall(0x10, &ireg, NULL);
 154                 }
 155         }
 156
 157         adjust_screen();
 158 }
 159
 160 /*
 161  * adjust_screen: Set the internal variables associated with the screen size.
 162  *              This is a subroutine in case we're loading a custom font.
 163  */
 164 void adjust_screen(void)
 165 {
 166         com32sys_t ireg, oreg;
 167         volatile uint8_t *vidrows = (volatile uint8_t *)BIOS_vidrows;
 168         uint8_t rows, cols;
 169
 170         rows = *vidrows;
 171         if (!rows) {
 172                 /*
 173                  * No vidrows in BIOS, assume 25.
 174                  * (Remember: vidrows == rows-1)
 175                  */
 176                 rows = 24;
 177         }
 178
 179         VidRows = rows;
 180
 181         ireg.eax.b[1] = 0x0f;   /* Read video state */
 182         __intcall(0x10, &ireg, &oreg);
 183         cols = oreg.eax.b[1];
 184
 185         VidCols = --cols;       /* Store count-1 (same as rows) */
 186 }
 187
 188 void pm_adjust_screen(com32sys_t *regs __unused)
 189 {
 190         adjust_screen();
 191 }
 192
 193 void pm_userfont(com32sys_t *regs)
 194 {
 195         regs->es = SEG(fontbuf);
 196         regs->ebx.w[0] = OFFS(fontbuf);
 197 }