freebsd-nq/sys/i386/boot/dosboot/dosboot.c
Poul-Henning Kamp 886b0df400 New and improved version from the author.
Submitted by:	DI. Christian Gusenbauer <cg@fimp01.fim.uni-linz.ac.at>
1995-04-27 18:22:36 +00:00

218 lines
6.6 KiB
C

/*
* dosboot.c Boot FreeBSD from DOS partition
*
* (C) 1994 by Christian Gusenbauer (cg@fimp01.fim.uni-linz.ac.at)
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* I ALLOW YOU USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. I DISCLAIM
* ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE
* USE OF THIS SOFTWARE.
*
* Parts of this file are
* Copyright (c) 1992, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
#include <bios.h>
#include <stdio.h>
#include <process.h>
#include "protmod.h"
#include "param.h"
#include "boot.h"
#include "bootinfo.h"
#include "reboot.h"
#include "exec.h"
#define BUFSIZE 4096
static struct exec head;
static long argv[10];
static long startaddr;
int biosread(int dev, int track, int head, int sector, int cnt, unsigned char far *buffer)
{
struct _diskinfo_t di;
int r;
di.drive = dev; /* first hard disk */
di.head = head; /* head # */
di.track = track; /* track # */
di.sector = sector+1; /* sector # */
di.nsectors = cnt; /* only 1 sector */
di.buffer = (void far *) buffer; /* sector buffer */
r= _bios_disk(_DISK_READ, &di);
return r&0xFF00;
}
static void dosxread(FILE *fp, unsigned long addr, long size)
{
extern char buf[BUFSIZE];
int count = BUFSIZE;
while (size > 0l) {
if (BUFSIZE > size)
count = (int) size;
fread(buf, count, 1, fp);
pm_copy(buf, addr, count);
size -= count;
addr += count;
}
}
static long loadprog(FILE *fp, long *hsize)
{
long int addr; /* physical address.. not directly useable */
long int hmaddress, pad, i;
static int (*x_entry)() = 0;
fread(&head, sizeof(head), 1, fp);
fseek(fp, 4096-sizeof(head), 1);
if (N_BADMAG(head)) {
printf("Invalid format!\n");
exit(0);
}
startaddr = (long)head.a_entry;
addr = (startaddr & 0x00ffffffl); /* some MEG boundary */
printf("Booting @ 0x%lx\n", addr);
if(addr < 0x100000l)
{
printf("Start address too low!\n");
exit(0);
}
poff = N_TXTOFF(head)+head.a_text+head.a_data+head.a_syms;
fseek(fp, poff, 0);
fread(&i, sizeof(i), 1, fp);
*hsize = head.a_text+head.a_data+head.a_bss;
*hsize = (*hsize+NBPG-1)&~(NBPG-1);
*hsize += i+4+head.a_syms;
addr=hmaddress=get_high_memory(*hsize);
if (!hmaddress) {
printf("Sorry, can't allocate enough memory!\n");
exit(0);
}
poff = N_TXTOFF(head);
fseek(fp, poff, 0);
/********************************************************/
/* LOAD THE TEXT SEGMENT */
/********************************************************/
printf("text=0x%lx ", head.a_text);
dosxread(fp, addr, head.a_text);
addr += head.a_text;
/********************************************************/
/* Load the Initialised data after the text */
/********************************************************/
while (addr & CLOFSET)
pm_copy("\0", addr++, 1);
printf("data=0x%lx ", head.a_data);
dosxread(fp, addr, head.a_data);
addr += head.a_data;
/********************************************************/
/* Skip over the uninitialised data */
/* (but clear it) */
/********************************************************/
printf("bss=0x%lx ", head.a_bss);
pbzero(addr, head.a_bss);
addr += head.a_bss;
/* Pad to a page boundary. */
pad = (unsigned long)(addr-hmaddress+(startaddr & 0x00ffffffl)) % NBPG;
if (pad != 0) {
pad = NBPG - pad;
addr += pad;
}
bootinfo.bi_symtab = addr-hmaddress+(startaddr & 0x00ffffffl);
/********************************************************/
/* Copy the symbol table size */
/********************************************************/
pm_copy((char *)&head.a_syms, addr, sizeof(head.a_syms));
addr += sizeof(head.a_syms);
/********************************************************/
/* Load the symbol table */
/********************************************************/
printf("symbols=[+0x%lx+0x%lx+0x%lx", pad, (long) sizeof(head.a_syms),
(long) head.a_syms);
dosxread(fp, addr, head.a_syms);
addr += head.a_syms;
/********************************************************/
/* Load the string table size */
/********************************************************/
fread((void *)&i, sizeof(long), 1, fp);
pm_copy((char *)&i, addr, sizeof(long));
i -= sizeof(long);
addr += sizeof(long);
/********************************************************/
/* Load the string table */
/********************************************************/
printf("+0x%x+0x%lx] ", sizeof(long), i);
dosxread(fp, addr, i);
addr += i;
bootinfo.bi_esymtab = addr-hmaddress+(startaddr & 0x00ffffffl);
/*
* For backwards compatibility, use the previously-unused adaptor
* and controller bitfields to hold the slice number.
*/
printf("total=0x%lx entry point=0x%lx\n",
addr-hmaddress+(startaddr & 0x00ffffffl),
startaddr & 0x00ffffffl);
return hmaddress;
}
void dosboot(long howto, char *kernel)
{
long hmaddress, size, bootdev;
FILE *fp;
fp = fopen(kernel, "rb"); /* open kernel for reading */
if (!fp) {
fprintf(stderr, "Sorry, can't open %s!\n", kernel);
return;
}
hmaddress = loadprog(fp, &size);
fclose(fp);
bootdev = MAKEBOOTDEV(maj, (slice >> 4), slice & 0xf, unit, part);
startprog(hmaddress, size, ((long)startaddr & 0xffffffl),
howto | RB_BOOTINFO, bootdev);
}