1 /* Based on original installboot from MINIX 3.
2  *
3  *	installboot 3.0 - Make a device bootable	Author: Kees J. Bot
4  *								21 Dec 1991
5  */
6 #if HAVE_NBTOOL_CONFIG_H
7 #include "nbtool_config.h"
8 #endif
9 
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <errno.h>
14 #include <fcntl.h>
15 #include <unistd.h>
16 #include <dirent.h>
17 #include <sys/stat.h>
18 
19 #include "installboot.h"
20 
21 #define BOOTBLOCK	0	/* Of course */
22 #define BOOT_BLOCK_SIZE 1024
23 #define SIGNATURE	0xAA55	/* Boot block signature. */
24 #define SIGPOS		510	/* Where to put signature word. */
25 #define PARTPOS		446	/* Offset to the partition table in a master
26 				 * boot block.
27 				 */
28 
29 
30 static int rawfd;	/* File descriptor to open device. */
31 static const char *rawdev;	/* Name of device. */
32 
33 
34 static void report(const char *label)
35 /* installboot: label: No such file or directory */
36 {
37 	fprintf(stderr, "installboot: %s: %s\n", label, strerror(errno));
38 }
39 
40 static __dead void fatal(const char *label)
41 {
42 	report(label);
43 	exit(1);
44 }
45 
46 static void bread(FILE *f, char *name, void *buf, size_t len)
47 /* Read len bytes.  Don't dare return without them. */
48 {
49 	if (len > 0 && fread(buf, len, 1, f) != 1) {
50 		if (ferror(f)) fatal(name);
51 		fprintf(stderr, "installboot: Unexpected EOF on %s\n", name);
52 		exit(1);
53 	}
54 }
55 
56 static void readblock(off_t blk, char *buf, int block_size)
57 /* For rawfs, so that it can read blocks. */
58 {
59 	int n;
60 
61 	if (lseek(rawfd, blk * block_size, SEEK_SET) < 0
62 		|| (n= read(rawfd, buf, block_size)) < 0
63 	) fatal(rawdev);
64 
65 	if (n < block_size) {
66 		fprintf(stderr, "installboot: Unexpected EOF on %s\n", rawdev);
67 		exit(1);
68 	}
69 }
70 
71 static void writeblock(off_t blk, const char *buf, int block_size)
72 /* Add a function to write blocks for local use. */
73 {
74 	if (lseek(rawfd, blk * block_size, SEEK_SET) < 0
75 		|| write(rawfd, buf, block_size) < 0
76 	) fatal(rawdev);
77 }
78 
79 
80 /* A temp stub until fdisk is ported to MINIX */
81 void install_master(const char *device, char *masterboot, char **guide)
82 /* Booting a hard disk is a two stage process:  The master bootstrap in sector
83  * 0 loads the bootstrap from sector 0 of the active partition which in turn
84  * starts the operating system.  This code installs such a master bootstrap
85  * on a hard disk.  If guide[0] is non-null then the master bootstrap is
86  * guided into booting a certain device.
87  */
88 {
89 	FILE *masf;
90 	unsigned long size;
91 	static char buf[BOOT_BLOCK_SIZE];
92 
93 	/* Open device. */
94 	if ((rawfd= open(rawdev= device, O_RDWR)) < 0) fatal(device);
95 
96 	/* Open the master boot code. */
97 	if ((masf= fopen(masterboot, "r")) == NULL) fatal(masterboot);
98 
99 	size= PARTPOS;
100 
101 	/* Read the master boot block, patch it, write. */
102 	readblock(BOOTBLOCK, buf, BOOT_BLOCK_SIZE);
103 
104 	memset(buf, 0, PARTPOS);
105 	(void) bread(masf, masterboot, buf, size);
106 
107 	/* Install signature. */
108 	buf[SIGPOS+0]= (SIGNATURE >> 0) & 0xFF;
109 	buf[SIGPOS+1]= (SIGNATURE >> 8) & 0xFF;
110 
111 	writeblock(BOOTBLOCK, buf, BOOT_BLOCK_SIZE);
112 }
113 
114 int isoption(const char *option, const char *test)
115 /* Check if the option argument is equals "test".  Also accept -i as short
116  * for -image, and the special case -x for -extract.
117  */
118 {
119 	if (strcmp(option, test) == 0) return 1;
120 	if (option[0] != '-' && strlen(option) != 2) return 0;
121 	if (option[1] == test[1]) return 1;
122 	if (option[1] == 'x' && test[1] == 'e') return 1;
123 	return 0;
124 }
125