bios_setup.c 6.48 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242
/*
 * (C) Copyright 2002
 * Daniel Engstrm, Omicron Ceti AB, daniel@omicron.se
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program 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 of
 * the License, or (at your option) any later version.
 *
 * This program 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 02111-1307 USA
 */


/*
 * Partly based on msbios.c from rolo 1.6:
 *----------------------------------------------------------------------
 * (C) Copyright 2000
 * Sysgo Real-Time Solutions GmbH
 * Klein-Winternheim, Germany
 *----------------------------------------------------------------------
 */

#include <common.h>
#include <pci.h>
#include <asm/realmode.h>
#include <asm/io.h>

DECLARE_GLOBAL_DATA_PTR;

#define NUMVECTS	256

#define BIOS_DATA        ((char*)0x400)
#define BIOS_DATA_SIZE   256
#define BIOS_BASE        ((char*)0xf0000)
#define BIOS_CS          0xf000

extern ulong _i386boot_bios;
extern ulong _i386boot_bios_size;

/* these are defined in a 16bit segment and needs
 * to be accessed with the RELOC_16_xxxx() macros below
 */
extern u16 ram_in_64kb_chunks;
extern u16 bios_equipment;
extern u8  pci_last_bus;

extern void *rm_int00;
extern void *rm_int01;
extern void *rm_int02;
extern void *rm_int03;
extern void *rm_int04;
extern void *rm_int05;
extern void *rm_int06;
extern void *rm_int07;
extern void *rm_int08;
extern void *rm_int09;
extern void *rm_int0a;
extern void *rm_int0b;
extern void *rm_int0c;
extern void *rm_int0d;
extern void *rm_int0e;
extern void *rm_int0f;
extern void *rm_int10;
extern void *rm_int11;
extern void *rm_int12;
extern void *rm_int13;
extern void *rm_int14;
extern void *rm_int15;
extern void *rm_int16;
extern void *rm_int17;
extern void *rm_int18;
extern void *rm_int19;
extern void *rm_int1a;
extern void *rm_int1b;
extern void *rm_int1c;
extern void *rm_int1d;
extern void *rm_int1e;
extern void *rm_int1f;
extern void *rm_def_int;

extern void *realmode_reset;
extern void *realmode_pci_bios_call_entry;

static int set_jmp_vector(int entry_point, void *target)
{
	if (entry_point & ~0xffff) {
		return -1;
	}

	if (((u32)target-0xf0000) & ~0xffff) {
		return -1;
	}
	printf("set_jmp_vector: 0xf000:%04x -> %p\n",
	       entry_point, target);

	/* jmp opcode */
	writeb(0xea, 0xf0000 + entry_point);

	/* offset */
	writew(((u32)target-0xf0000), 0xf0000 + entry_point + 1);

	/* segment */
	writew(0xf000, 0xf0000 + entry_point + 3);

	return 0;
}


/*
 ************************************************************
 * Install an interrupt vector
 ************************************************************
 */

static void setvector(int vector, u16 segment, void *handler)
{
	u16 *ptr = (u16*)(vector*4);
	ptr[0] = ((u32)handler - (segment << 4))&0xffff;
	ptr[1] = segment;

#if 0
	printf("setvector: int%02x -> %04x:%04x\n",
	       vector, ptr[1], ptr[0]);
#endif
}

#define RELOC_16_LONG(seg, off) *(u32*)(seg << 4 | (u32)&off)
#define RELOC_16_WORD(seg, off) *(u16*)(seg << 4 | (u32)&off)
#define RELOC_16_BYTE(seg, off) *(u8*)(seg << 4 | (u32)&off)

int bios_setup(void)
{
	ulong i386boot_bios      = (ulong)&_i386boot_bios;
	ulong i386boot_bios_size = (ulong)&_i386boot_bios_size;

	static int done=0;
	int vector;
#ifdef CONFIG_PCI
	struct pci_controller *pri_hose;
#endif
	if (done) {
		return 0;
	}
	done = 1;

	if (i386boot_bios_size > 65536) {
		printf("BIOS too large (%ld bytes, max is 65536)\n",
		       i386boot_bios_size);
		return -1;
	}

	memcpy(BIOS_BASE, (void*)i386boot_bios, i386boot_bios_size);

	/* clear bda */
	memset(BIOS_DATA, 0, BIOS_DATA_SIZE);

	/* enter some values to the bda */
	writew(0x3f8, BIOS_DATA);   /* com1 addr */
	writew(0x2f8, BIOS_DATA+2); /* com2 addr */
	writew(0x3e8, BIOS_DATA+4); /* com3 addr */
	writew(0x2e8, BIOS_DATA+6); /* com4 addr */
	writew(0x278, BIOS_DATA+8); /* lpt1 addr */
	/*
	 * The kernel wants to read the base memory size
	 * from 40:13. Put a zero there to avoid an error message
	 */
	writew(0, BIOS_DATA+0x13);  /* base memory size */


	/* setup realmode interrupt vectors */
	for (vector = 0; vector < NUMVECTS; vector++) {
		setvector(vector, BIOS_CS, &rm_def_int);
	}

	setvector(0x00, BIOS_CS, &rm_int00);
	setvector(0x01, BIOS_CS, &rm_int01);
	setvector(0x02, BIOS_CS, &rm_int02);
	setvector(0x03, BIOS_CS, &rm_int03);
	setvector(0x04, BIOS_CS, &rm_int04);
	setvector(0x05, BIOS_CS, &rm_int05);
	setvector(0x06, BIOS_CS, &rm_int06);
	setvector(0x07, BIOS_CS, &rm_int07);
	setvector(0x08, BIOS_CS, &rm_int08);
	setvector(0x09, BIOS_CS, &rm_int09);
	setvector(0x0a, BIOS_CS, &rm_int0a);
	setvector(0x0b, BIOS_CS, &rm_int0b);
	setvector(0x0c, BIOS_CS, &rm_int0c);
	setvector(0x0d, BIOS_CS, &rm_int0d);
	setvector(0x0e, BIOS_CS, &rm_int0e);
	setvector(0x0f, BIOS_CS, &rm_int0f);
	setvector(0x10, BIOS_CS, &rm_int10);
	setvector(0x11, BIOS_CS, &rm_int11);
	setvector(0x12, BIOS_CS, &rm_int12);
	setvector(0x13, BIOS_CS, &rm_int13);
	setvector(0x14, BIOS_CS, &rm_int14);
	setvector(0x15, BIOS_CS, &rm_int15);
	setvector(0x16, BIOS_CS, &rm_int16);
	setvector(0x17, BIOS_CS, &rm_int17);
	setvector(0x18, BIOS_CS, &rm_int18);
	setvector(0x19, BIOS_CS, &rm_int19);
	setvector(0x1a, BIOS_CS, &rm_int1a);
	setvector(0x1b, BIOS_CS, &rm_int1b);
	setvector(0x1c, BIOS_CS, &rm_int1c);
	setvector(0x1d, BIOS_CS, &rm_int1d);
	setvector(0x1e, BIOS_CS, &rm_int1e);
	setvector(0x1f, BIOS_CS, &rm_int1f);

	set_jmp_vector(0xfff0, &realmode_reset);
	set_jmp_vector(0xfe6e, &realmode_pci_bios_call_entry);

	/* fill in data area */
	RELOC_16_WORD(0xf000, ram_in_64kb_chunks) = gd->ram_size >> 16;
	RELOC_16_WORD(0xf000, bios_equipment) = 0; /* FixMe */

	/* If we assume only one PCI hose, this PCI hose
	 * will own PCI bus #0, and the last PCI bus of
	 * that PCI hose will be the last PCI bus in the
	 * system.
	 * (This, ofcause break on multi hose systems,
	 *  but our PCI BIOS only support one hose anyway)
	 */
#ifdef CONFIG_PCI
	pri_hose = pci_bus_to_hose(0);
	if (NULL != pri_hose) {
		/* fill in last pci bus number for use by the realmode
		 * PCI BIOS */
		RELOC_16_BYTE(0xf000, pci_last_bus) = pri_hose->last_busno;
	}
#endif
	return 0;
}