1/*
2 *  linux/tools/build.c
3 *
4 *  Copyright (C) 1991, 1992  Linus Torvalds
5 */
6
7/*
8 * This file builds a disk-image from three different files:
9 *
10 * - bootsect: exactly 512 bytes of 8086 machine code, loads the rest
11 * - setup: 8086 machine code, sets up system parm
12 * - system: 80386 code for actual system
13 *
14 * It does some checking that all files are of the correct type, and
15 * just writes the result to stdout, removing headers and padding to
16 * the right amount. It also writes some system data to stderr.
17 */
18
19/*
20 * Changes by tytso to allow root device specification
21 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
22 * Cross compiling fixes by Gertjan van Wingerde, July 1996
23 */
24
25#include <stdio.h>	/* fprintf */
26#include <string.h>
27#include <stdlib.h>	/* contains exit */
28#include <sys/types.h>	/* unistd.h needs this */
29#include <sys/stat.h>
30#include <sys/sysmacros.h>
31#include <unistd.h>	/* contains read/write */
32#include <fcntl.h>
33#include <errno.h>
34
35#define MINIX_HEADER 32
36
37#define N_MAGIC_OFFSET 1024
38#ifndef __BFD__
39static int GCC_HEADER = sizeof(struct exec);
40#endif
41
42#ifdef __BIG_KERNEL__
43#define SYS_SIZE 0xffff
44#else
45#define SYS_SIZE DEF_SYSSIZE
46#endif
47
48#define DEFAULT_MAJOR_ROOT 0
49#define DEFAULT_MINOR_ROOT 0
50
51/* max nr of sectors of setup: don't change unless you also change
52 * bootsect etc */
53#define SETUP_SECTS 4
54
55#define STRINGIFY(x) #x
56
57typedef union {
58	int i;
59	long l;
60	short s[2];
61	char b[4];
62} conv;
63
64long intel_long(long l)
65{
66	conv t;
67
68	t.b[0] = l & 0xff; l >>= 8;
69	t.b[1] = l & 0xff; l >>= 8;
70	t.b[2] = l & 0xff; l >>= 8;
71	t.b[3] = l & 0xff; l >>= 8;
72	return t.l;
73}
74
75int intel_int(int i)
76{
77	conv t;
78
79	t.b[0] = i & 0xff; i >>= 8;
80        t.b[1] = i & 0xff; i >>= 8;
81        t.b[2] = i & 0xff; i >>= 8;
82        t.b[3] = i & 0xff; i >>= 8;
83        return t.i;
84}
85
86short intel_short(short l)
87{
88	conv t;
89
90	t.b[0] = l & 0xff; l >>= 8;
91	t.b[1] = l & 0xff; l >>= 8;
92	return t.s[0];
93}
94
95void die(const char * str)
96{
97	fprintf(stderr,"%s\n",str);
98	exit(1);
99}
100
101void usage(void)
102{
103	die("Usage: build bootsect setup system [rootdev] [> image]");
104}
105
106int main(int argc, char ** argv)
107{
108	int i,c,id,sz,tmp_int;
109	unsigned long sys_size, tmp_long;
110	char buf[1024];
111#ifndef __BFD__
112	struct exec *ex = (struct exec *)buf;
113#endif
114	char major_root, minor_root;
115	struct stat sb;
116	unsigned char setup_sectors;
117
118	if ((argc < 4) || (argc > 5))
119		usage();
120	if (argc > 4) {
121		if (!strcmp(argv[4], "CURRENT")) {
122			if (stat("/", &sb)) {
123				perror("/");
124				die("Couldn't stat /");
125			}
126			major_root = major(sb.st_dev);
127			minor_root = minor(sb.st_dev);
128		} else if (strcmp(argv[4], "FLOPPY")) {
129			if (stat(argv[4], &sb)) {
130				perror(argv[4]);
131				die("Couldn't stat root device.");
132			}
133			major_root = major(sb.st_rdev);
134			minor_root = minor(sb.st_rdev);
135		} else {
136			major_root = 0;
137			minor_root = 0;
138		}
139	} else {
140		major_root = DEFAULT_MAJOR_ROOT;
141		minor_root = DEFAULT_MINOR_ROOT;
142	}
143	fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);
144	for (i=0;i<sizeof buf; i++) buf[i]=0;
145	if ((id=open(argv[1],O_RDONLY,0))<0)
146		die("Unable to open 'boot'");
147	if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)
148		die("Unable to read header of 'boot'");
149	if (((long *) buf)[0]!=intel_long(0x04100301))
150		die("Non-Minix header of 'boot'");
151	if (((long *) buf)[1]!=intel_long(MINIX_HEADER))
152		die("Non-Minix header of 'boot'");
153	if (((long *) buf)[3] != 0)
154		die("Illegal data segment in 'boot'");
155	if (((long *) buf)[4] != 0)
156		die("Illegal bss in 'boot'");
157	if (((long *) buf)[5] != 0)
158		die("Non-Minix header of 'boot'");
159	if (((long *) buf)[7] != 0)
160		die("Illegal symbol table in 'boot'");
161	i=read(id,buf,sizeof buf);
162	fprintf(stderr,"Boot sector %d bytes.\n",i);
163	if (i != 512)
164		die("Boot block must be exactly 512 bytes");
165	if ((*(unsigned short *)(buf+510)) != (unsigned short)intel_short(0xAA55))
166		die("Boot block hasn't got boot flag (0xAA55)");
167	buf[508] = (char) minor_root;
168	buf[509] = (char) major_root;
169	i=write(1,buf,512);
170	if (i!=512)
171		die("Write call failed");
172	close (id);
173
174	if ((id=open(argv[2],O_RDONLY,0))<0)
175		die("Unable to open 'setup'");
176	if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)
177		die("Unable to read header of 'setup'");
178	if (((long *) buf)[0]!=intel_long(0x04100301))
179		die("Non-Minix header of 'setup'");
180	if (((long *) buf)[1]!=intel_long(MINIX_HEADER))
181		die("Non-Minix header of 'setup'");
182	if (((long *) buf)[3] != 0)
183		die("Illegal data segment in 'setup'");
184	if (((long *) buf)[4] != 0)
185		die("Illegal bss in 'setup'");
186	if (((long *) buf)[5] != 0)
187		die("Non-Minix header of 'setup'");
188	if (((long *) buf)[7] != 0)
189		die("Illegal symbol table in 'setup'");
190	for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c )
191#ifdef __BIG_KERNEL__
192	{
193		if (!i) {
194			/* Working with memcpy because of alignment constraints
195			   on Sparc - Gertjan */
196			memcpy(&tmp_long, &buf[2], sizeof(long));
197			if (tmp_long != intel_long(0x53726448) )
198				die("Wrong magic in loader header of 'setup'");
199			memcpy(&tmp_int, &buf[6], sizeof(int));
200			if (tmp_int < intel_int(0x200))
201				die("Wrong version of loader header of 'setup'");
202			buf[0x11] = 1; /* LOADED_HIGH */
203			tmp_long = intel_long(0x100000);
204			memcpy(&buf[0x14], &tmp_long, sizeof(long));  /* code32_start */
205		}
206#endif
207		if (write(1,buf,c)!=c)
208			die("Write call failed");
209#ifdef __BIG_KERNEL__
210	}
211#endif
212	if (c != 0)
213		die("read-error on 'setup'");
214	close (id);
215	setup_sectors = (unsigned char)((i + 511) / 512);
216	/* for compatibility with LILO */
217	if (setup_sectors < SETUP_SECTS)
218		setup_sectors = SETUP_SECTS;
219	fprintf(stderr,"Setup is %d bytes.\n",i);
220	for (c=0 ; c<sizeof(buf) ; c++)
221		buf[c] = '\0';
222	while (i < setup_sectors * 512) {
223		c = setup_sectors * 512 - i;
224		if (c > sizeof(buf))
225			c = sizeof(buf);
226		if (write(1,buf,c) != c)
227			die("Write call failed");
228		i += c;
229	}
230
231	if ((id=open(argv[3],O_RDONLY,0))<0)
232		die("Unable to open 'system'");
233#ifndef __BFD__
234	if (read(id,buf,GCC_HEADER) != GCC_HEADER)
235		die("Unable to read header of 'system'");
236	if (N_MAGIC(*ex) == ZMAGIC) {
237		GCC_HEADER = N_MAGIC_OFFSET;
238		lseek(id, GCC_HEADER, SEEK_SET);
239	} else if (N_MAGIC(*ex) != QMAGIC)
240		die("Non-GCC header of 'system'");
241	fprintf(stderr,"System is %d kB (%d kB code, %d kB data and %d kB bss)\n",
242		(ex->a_text+ex->a_data+ex->a_bss)/1024,
243		ex->a_text /1024,
244		ex->a_data /1024,
245		ex->a_bss  /1024);
246	sz = N_SYMOFF(*ex) - GCC_HEADER + 4;
247#else
248	if (fstat (id, &sb)) {
249	  perror ("fstat");
250	  die ("Unable to stat 'system'");
251	}
252	sz = sb.st_size;
253	fprintf (stderr, "System is %d kB\n", sz/1024);
254#endif
255	sys_size = (sz + 15) / 16;
256	if (sys_size > SYS_SIZE)
257		die("System is too big");
258	while (sz > 0) {
259		int l, n;
260
261		l = sz;
262		if (l > sizeof(buf))
263			l = sizeof(buf);
264		if ((n=read(id, buf, l)) != l) {
265			if (n == -1)
266				perror(argv[1]);
267			else
268				fprintf(stderr, "Unexpected EOF\n");
269			die("Can't read 'system'");
270		}
271		if (write(1, buf, l) != l)
272			die("Write failed");
273		sz -= l;
274	}
275	close(id);
276	if (lseek(1, 497, 0) == 497) {
277		if (write(1, &setup_sectors, 1) != 1)
278			die("Write of setup sectors failed");
279	}
280	if (lseek(1,500,0) == 500) {
281		buf[0] = (sys_size & 0xff);
282		buf[1] = ((sys_size >> 8) & 0xff);
283		if (write(1, buf, 2) != 2)
284			die("Write failed");
285	}
286	return(0);
287}
288