/* *  linux/tools/build.c * *  Copyright (C) 1991, 1992  Linus Torvalds *//* * This file builds a disk-image from three different files: * * - bootsect: max 510 bytes of 8086 machine code, loads the rest * - setup: max 4 sectors of 8086 machine code, sets up system parm * - system: 80386 code for actual system * * It does some checking that all files are of the correct type, and * just writes the result to stdout, removing headers and padding to * the right amount. It also writes some system data to stderr. *//* * Changes by tytso to allow root device specification */#include <stdio.h>	/* fprintf */#include <string.h>#include <stdlib.h>	/* contains exit */#include <sys/types.h>	/* unistd.h needs this */#include <sys/stat.h>#include <sys/sysmacros.h>#include <unistd.h>	/* contains read/write */#include <fcntl.h>#include <linux/config.h>#include <linux/a.out.h>#define MINIX_HEADER 32#define GCC_HEADER 1024#define SYS_SIZE DEF_SYSSIZE#define DEFAULT_MAJOR_ROOT 0#define DEFAULT_MINOR_ROOT 0/* max nr of sectors of setup: don't change unless you also change * bootsect etc */#define SETUP_SECTS 4#define STRINGIFY(x) #xtypedef union {	long l;	short s[2];	char b[4];} conv;long intel_long(long l){	conv t;	t.b[0] = l & 0xff; l >>= 8;	t.b[1] = l & 0xff; l >>= 8;	t.b[2] = l & 0xff; l >>= 8;	t.b[3] = l & 0xff; l >>= 8;	return t.l;}short intel_short(short l){	conv t;	t.b[0] = l & 0xff; l >>= 8;	t.b[1] = l & 0xff; l >>= 8;	return t.s[0];}void die(char * str){	fprintf(stderr,"%s\n",str);	exit(1);}void usage(void){	die("Usage: build bootsect setup system [rootdev] [> image]");}int main(int argc, char ** argv){	int i,c,id, sz;	unsigned long sys_size;	char buf[1024];	struct exec *ex = (struct exec *)buf;	char major_root, minor_root;	struct stat sb;	if ((argc < 4) || (argc > 5))		usage();	if (argc > 4) {		if (!strcmp(argv[4], "CURRENT")) {			if (stat("/", &sb)) {				perror("/");				die("Couldn't stat /");			}			major_root = major(sb.st_dev);			minor_root = minor(sb.st_dev);		} else if (strcmp(argv[4], "FLOPPY")) {			if (stat(argv[4], &sb)) {				perror(argv[4]);				die("Couldn't stat root device.");			}			major_root = major(sb.st_rdev);			minor_root = minor(sb.st_rdev);		} else {			major_root = 0;			minor_root = 0;		}	} else {		major_root = DEFAULT_MAJOR_ROOT;		minor_root = DEFAULT_MINOR_ROOT;	}	fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);	for (i=0;i<sizeof buf; i++) buf[i]=0;	if ((id=open(argv[1],O_RDONLY,0))<0)		die("Unable to open 'boot'");	if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)		die("Unable to read header of 'boot'");	if (((long *) buf)[0]!=intel_long(0x04100301))		die("Non-Minix header of 'boot'");	if (((long *) buf)[1]!=intel_long(MINIX_HEADER))		die("Non-Minix header of 'boot'");	if (((long *) buf)[3] != 0)		die("Illegal data segment in 'boot'");	if (((long *) buf)[4] != 0)		die("Illegal bss in 'boot'");	if (((long *) buf)[5] != 0)		die("Non-Minix header of 'boot'");	if (((long *) buf)[7] != 0)		die("Illegal symbol table in 'boot'");	i=read(id,buf,sizeof buf);	fprintf(stderr,"Boot sector %d bytes.\n",i);	if (i != 512)		die("Boot block must be exactly 512 bytes");	if ((*(unsigned short *)(buf+510)) != (unsigned short)intel_short(0xAA55))		die("Boot block hasn't got boot flag (0xAA55)");	buf[508] = (char) minor_root;	buf[509] = (char) major_root;		i=write(1,buf,512);	if (i!=512)		die("Write call failed");	close (id);		if ((id=open(argv[2],O_RDONLY,0))<0)		die("Unable to open 'setup'");	if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)		die("Unable to read header of 'setup'");	if (((long *) buf)[0]!=intel_long(0x04100301))		die("Non-Minix header of 'setup'");	if (((long *) buf)[1]!=intel_long(MINIX_HEADER))		die("Non-Minix header of 'setup'");	if (((long *) buf)[3] != 0)		die("Illegal data segment in 'setup'");	if (((long *) buf)[4] != 0)		die("Illegal bss in 'setup'");	if (((long *) buf)[5] != 0)		die("Non-Minix header of 'setup'");	if (((long *) buf)[7] != 0)		die("Illegal symbol table in 'setup'");	for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c )		if (write(1,buf,c)!=c)			die("Write call failed");	if (c != 0)		die("read-error on 'setup'");	close (id);	if (i > SETUP_SECTS*512)		die("Setup exceeds " STRINGIFY(SETUP_SECTS)			" sectors - rewrite build/boot/setup");	fprintf(stderr,"Setup is %d bytes.\n",i);	for (c=0 ; c<sizeof(buf) ; c++)		buf[c] = '\0';	while (i<SETUP_SECTS*512) {		c = SETUP_SECTS*512-i;		if (c > sizeof(buf))			c = sizeof(buf);		if (write(1,buf,c) != c)			die("Write call failed");		i += c;	}		if ((id=open(argv[3],O_RDONLY,0))<0)		die("Unable to open 'system'");	if (read(id,buf,GCC_HEADER) != GCC_HEADER)		die("Unable to read header of 'system'");	if (N_MAGIC(*ex) != ZMAGIC)		die("Non-GCC header of 'system'");	fprintf(stderr,"System is %d kB (%d kB code, %d kB data and %d kB bss)\n",		(ex->a_text+ex->a_data+ex->a_bss)/1024,		ex->a_text /1024,		ex->a_data /1024,		ex->a_bss  /1024);	sz = N_SYMOFF(*ex) - GCC_HEADER + 4;	sys_size = (sz + 15) / 16;	if (sys_size > SYS_SIZE)		die("System is too big");	while (sz > 0) {		int l, n;		l = sz;		if (l > sizeof(buf))			l = sizeof(buf);		if ((n=read(id, buf, l)) != l) {			if (n == -1) 				perror(argv[1]);			else				fprintf(stderr, "Unexpected EOF\n");			die("Can't read 'system'");		}		if (write(1, buf, l) != l)			die("Write failed");		sz -= l;	}	close(id);	if (lseek(1,500,0) == 500) {		buf[0] = (sys_size & 0xff);		buf[1] = ((sys_size >> 8) & 0xff);		if (write(1, buf, 2) != 2)			die("Write failed");	}	return(0);}