120 lines
3.2 KiB
C
120 lines
3.2 KiB
C
/* Based on original installboot from MINIX 3.
|
|
*
|
|
* installboot 3.0 - Make a device bootable Author: Kees J. Bot
|
|
* 21 Dec 1991
|
|
*/
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <dirent.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include "installboot.h"
|
|
|
|
#define BOOTBLOCK 0 /* Of course */
|
|
#define BOOT_BLOCK_SIZE 1024
|
|
#define SIGNATURE 0xAA55 /* Boot block signature. */
|
|
#define SIGPOS 510 /* Where to put signature word. */
|
|
#define PARTPOS 446 /* Offset to the partition table in a master
|
|
* boot block.
|
|
*/
|
|
|
|
|
|
static int rawfd; /* File descriptor to open device. */
|
|
static const char *rawdev; /* Name of device. */
|
|
|
|
|
|
static void report(const char *label)
|
|
/* installboot: label: No such file or directory */
|
|
{
|
|
fprintf(stderr, "installboot: %s: %s\n", label, strerror(errno));
|
|
}
|
|
|
|
static void fatal(const char *label)
|
|
{
|
|
report(label);
|
|
exit(1);
|
|
}
|
|
|
|
static void bread(FILE *f, char *name, void *buf, size_t len)
|
|
/* Read len bytes. Don't dare return without them. */
|
|
{
|
|
if (len > 0 && fread(buf, len, 1, f) != 1) {
|
|
if (ferror(f)) fatal(name);
|
|
fprintf(stderr, "installboot: Unexpected EOF on %s\n", name);
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
static void readblock(off_t blk, char *buf, int block_size)
|
|
/* For rawfs, so that it can read blocks. */
|
|
{
|
|
int n;
|
|
|
|
if (lseek(rawfd, blk * block_size, SEEK_SET) < 0
|
|
|| (n= read(rawfd, buf, block_size)) < 0
|
|
) fatal(rawdev);
|
|
|
|
if (n < block_size) {
|
|
fprintf(stderr, "installboot: Unexpected EOF on %s\n", rawdev);
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
static void writeblock(off_t blk, const char *buf, int block_size)
|
|
/* Add a function to write blocks for local use. */
|
|
{
|
|
if (lseek(rawfd, blk * block_size, SEEK_SET) < 0
|
|
|| write(rawfd, buf, block_size) < 0
|
|
) fatal(rawdev);
|
|
}
|
|
|
|
|
|
/* A temp stub until fdisk is ported to MINIX */
|
|
void install_master(const char *device, char *masterboot, char **guide)
|
|
/* Booting a hard disk is a two stage process: The master bootstrap in sector
|
|
* 0 loads the bootstrap from sector 0 of the active partition which in turn
|
|
* starts the operating system. This code installs such a master bootstrap
|
|
* on a hard disk. If guide[0] is non-null then the master bootstrap is
|
|
* guided into booting a certain device.
|
|
*/
|
|
{
|
|
FILE *masf;
|
|
unsigned long size;
|
|
static char buf[_MAX_BLOCK_SIZE];
|
|
|
|
/* Open device. */
|
|
if ((rawfd= open(rawdev= device, O_RDWR)) < 0) fatal(device);
|
|
|
|
/* Open the master boot code. */
|
|
if ((masf= fopen(masterboot, "r")) == NULL) fatal(masterboot);
|
|
|
|
size= PARTPOS;
|
|
|
|
/* Read the master boot block, patch it, write. */
|
|
readblock(BOOTBLOCK, buf, BOOT_BLOCK_SIZE);
|
|
|
|
memset(buf, 0, PARTPOS);
|
|
(void) bread(masf, masterboot, buf, size);
|
|
|
|
/* Install signature. */
|
|
buf[SIGPOS+0]= (SIGNATURE >> 0) & 0xFF;
|
|
buf[SIGPOS+1]= (SIGNATURE >> 8) & 0xFF;
|
|
|
|
writeblock(BOOTBLOCK, buf, BOOT_BLOCK_SIZE);
|
|
}
|
|
|
|
int isoption(const char *option, const char *test)
|
|
/* Check if the option argument is equals "test". Also accept -i as short
|
|
* for -image, and the special case -x for -extract.
|
|
*/
|
|
{
|
|
if (strcmp(option, test) == 0) return 1;
|
|
if (option[0] != '-' && strlen(option) != 2) return 0;
|
|
if (option[1] == test[1]) return 1;
|
|
if (option[1] == 'x' && test[1] == 'e') return 1;
|
|
return 0;
|
|
}
|