lib_i386/bios_setup.c

   1 /*
   2  * (C) Copyright 2002
   3  * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24
  25 /*
  26  * Partly based on msbios.c from rolo 1.6:
  27  *----------------------------------------------------------------------
  28  * (C) Copyright 2000
  29  * Sysgo Real-Time Solutions GmbH
  30  * Klein-Winternheim, Germany
  31  *----------------------------------------------------------------------
  32  */
  33
  34 #include <common.h>
  35 #include <pci.h>
  36 #include <asm/realmode.h>
  37 #include <asm/io.h>
  38
  39 DECLARE_GLOBAL_DATA_PTR;
  40
  41 #define NUMVECTS        256
  42
  43 #define BIOS_DATA        ((char*)0x400)
  44 #define BIOS_DATA_SIZE   256
  45 #define BIOS_BASE        ((char*)0xf0000)
  46 #define BIOS_CS          0xf000
  47
  48 extern ulong _i386boot_bios;
  49 extern ulong _i386boot_bios_size;
  50
  51 /* these are defined in a 16bit segment and needs
  52  * to be accessed with the RELOC_16_xxxx() macros below
  53  */
  54 extern u16 ram_in_64kb_chunks;
  55 extern u16 bios_equipment;
  56 extern u8  pci_last_bus;
  57
  58 extern void *rm_int00;
  59 extern void *rm_int01;
  60 extern void *rm_int02;
  61 extern void *rm_int03;
  62 extern void *rm_int04;
  63 extern void *rm_int05;
  64 extern void *rm_int06;
  65 extern void *rm_int07;
  66 extern void *rm_int08;
  67 extern void *rm_int09;
  68 extern void *rm_int0a;
  69 extern void *rm_int0b;
  70 extern void *rm_int0c;
  71 extern void *rm_int0d;
  72 extern void *rm_int0e;
  73 extern void *rm_int0f;
  74 extern void *rm_int10;
  75 extern void *rm_int11;
  76 extern void *rm_int12;
  77 extern void *rm_int13;
  78 extern void *rm_int14;
  79 extern void *rm_int15;
  80 extern void *rm_int16;
  81 extern void *rm_int17;
  82 extern void *rm_int18;
  83 extern void *rm_int19;
  84 extern void *rm_int1a;
  85 extern void *rm_int1b;
  86 extern void *rm_int1c;
  87 extern void *rm_int1d;
  88 extern void *rm_int1e;
  89 extern void *rm_int1f;
  90 extern void *rm_def_int;
  91
  92 extern void *realmode_reset;
  93 extern void *realmode_pci_bios_call_entry;
  94
  95 static int set_jmp_vector(int entry_point, void *target)
  96 {
  97         if (entry_point & ~0xffff) {
  98                 return -1;
  99         }
 100
 101         if (((u32)target-0xf0000) & ~0xffff) {
 102                 return -1;
 103         }
 104         printf("set_jmp_vector: 0xf000:%04x -> %p\n",
 105                entry_point, target);
 106
 107         /* jmp opcode */
 108         writeb(0xea, 0xf0000 + entry_point);
 109
 110         /* offset */
 111         writew(((u32)target-0xf0000), 0xf0000 + entry_point + 1);
 112
 113         /* segment */
 114         writew(0xf000, 0xf0000 + entry_point + 3);
 115
 116         return 0;
 117 }
 118
 119
 120 /*
 121  ************************************************************
 122  * Install an interrupt vector
 123  ************************************************************
 124  */
 125
 126 static void setvector(int vector, u16 segment, void *handler)
 127 {
 128         u16 *ptr = (u16*)(vector*4);
 129         ptr[0] = ((u32)handler - (segment << 4))&0xffff;
 130         ptr[1] = segment;
 131
 132 #if 0
 133         printf("setvector: int%02x -> %04x:%04x\n",
 134                vector, ptr[1], ptr[0]);
 135 #endif
 136 }
 137
 138 #define RELOC_16_LONG(seg, off) *(u32*)(seg << 4 | (u32)&off)
 139 #define RELOC_16_WORD(seg, off) *(u16*)(seg << 4 | (u32)&off)
 140 #define RELOC_16_BYTE(seg, off) *(u8*)(seg << 4 | (u32)&off)
 141
 142 int bios_setup(void)
 143 {
 144         ulong i386boot_bios      = (ulong)&_i386boot_bios;
 145         ulong i386boot_bios_size = (ulong)&_i386boot_bios_size;
 146
 147         static int done=0;
 148         int vector;
 149 #ifdef CONFIG_PCI
 150         struct pci_controller *pri_hose;
 151 #endif
 152         if (done) {
 153                 return 0;
 154         }
 155         done = 1;
 156
 157         if (i386boot_bios_size > 65536) {
 158                 printf("BIOS too large (%ld bytes, max is 65536)\n",
 159                        i386boot_bios_size);
 160                 return -1;
 161         }
 162
 163         memcpy(BIOS_BASE, (void*)i386boot_bios, i386boot_bios_size);
 164
 165         /* clear bda */
 166         memset(BIOS_DATA, 0, BIOS_DATA_SIZE);
 167
 168         /* enter some values to the bda */
 169         writew(0x3f8, BIOS_DATA);   /* com1 addr */
 170         writew(0x2f8, BIOS_DATA+2); /* com2 addr */
 171         writew(0x3e8, BIOS_DATA+4); /* com3 addr */
 172         writew(0x2e8, BIOS_DATA+6); /* com4 addr */
 173         writew(0x278, BIOS_DATA+8); /* lpt1 addr */
 174         /*
 175          * The kernel wants to read the base memory size
 176          * from 40:13. Put a zero there to avoid an error message
 177          */
 178         writew(0, BIOS_DATA+0x13);  /* base memory size */
 179
 180
 181         /* setup realmode interrupt vectors */
 182         for (vector = 0; vector < NUMVECTS; vector++) {
 183                 setvector(vector, BIOS_CS, &rm_def_int);
 184         }
 185
 186         setvector(0x00, BIOS_CS, &rm_int00);
 187         setvector(0x01, BIOS_CS, &rm_int01);
 188         setvector(0x02, BIOS_CS, &rm_int02);
 189         setvector(0x03, BIOS_CS, &rm_int03);
 190         setvector(0x04, BIOS_CS, &rm_int04);
 191         setvector(0x05, BIOS_CS, &rm_int05);
 192         setvector(0x06, BIOS_CS, &rm_int06);
 193         setvector(0x07, BIOS_CS, &rm_int07);
 194         setvector(0x08, BIOS_CS, &rm_int08);
 195         setvector(0x09, BIOS_CS, &rm_int09);
 196         setvector(0x0a, BIOS_CS, &rm_int0a);
 197         setvector(0x0b, BIOS_CS, &rm_int0b);
 198         setvector(0x0c, BIOS_CS, &rm_int0c);
 199         setvector(0x0d, BIOS_CS, &rm_int0d);
 200         setvector(0x0e, BIOS_CS, &rm_int0e);
 201         setvector(0x0f, BIOS_CS, &rm_int0f);
 202         setvector(0x10, BIOS_CS, &rm_int10);
 203         setvector(0x11, BIOS_CS, &rm_int11);
 204         setvector(0x12, BIOS_CS, &rm_int12);
 205         setvector(0x13, BIOS_CS, &rm_int13);
 206         setvector(0x14, BIOS_CS, &rm_int14);
 207         setvector(0x15, BIOS_CS, &rm_int15);
 208         setvector(0x16, BIOS_CS, &rm_int16);
 209         setvector(0x17, BIOS_CS, &rm_int17);
 210         setvector(0x18, BIOS_CS, &rm_int18);
 211         setvector(0x19, BIOS_CS, &rm_int19);
 212         setvector(0x1a, BIOS_CS, &rm_int1a);
 213         setvector(0x1b, BIOS_CS, &rm_int1b);
 214         setvector(0x1c, BIOS_CS, &rm_int1c);
 215         setvector(0x1d, BIOS_CS, &rm_int1d);
 216         setvector(0x1e, BIOS_CS, &rm_int1e);
 217         setvector(0x1f, BIOS_CS, &rm_int1f);
 218
 219         set_jmp_vector(0xfff0, &realmode_reset);
 220         set_jmp_vector(0xfe6e, &realmode_pci_bios_call_entry);
 221
 222         /* fill in data area */
 223         RELOC_16_WORD(0xf000, ram_in_64kb_chunks) = gd->ram_size >> 16;
 224         RELOC_16_WORD(0xf000, bios_equipment) = 0; /* FixMe */
 225
 226         /* If we assume only one PCI hose, this PCI hose
 227          * will own PCI bus #0, and the last PCI bus of
 228          * that PCI hose will be the last PCI bus in the
 229          * system.
 230          * (This, ofcause break on multi hose systems,
 231          *  but our PCI BIOS only support one hose anyway)
 232          */
 233 #ifdef CONFIG_PCI
 234         pri_hose = pci_bus_to_hose(0);
 235         if (NULL != pri_hose) {
 236                 /* fill in last pci bus number for use by the realmode
 237                  * PCI BIOS */
 238                 RELOC_16_BYTE(0xf000, pci_last_bus) = pri_hose->last_busno;
 239         }
 240 #endif
 241         return 0;
 242 }