/*
* linux/tools/build.c
*
* (C) 1991 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
*
* Added swap-device specification: Linux 20.12.91
*/
#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 <linux/fs.h>
#include <unistd.h> /* contains read/write */
#include <fcntl.h>
#define MINIX_HEADER 32
#define GCC_HEADER 1024
#define SYS_SIZE 0x3000
#define DEFAULT_MAJOR_ROOT 3
#define DEFAULT_MINOR_ROOT 6
#define DEFAULT_MAJOR_SWAP 0
#define DEFAULT_MINOR_SWAP 0
/* max nr of sectors of setup: don't change unless you also change
* bootsect etc */
#define SETUP_SECTS 4
#define STRINGIFY(x) #x
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;
char buf[1024];
char major_root, minor_root;
char major_swap, minor_swap;
struct stat sb;
if ((argc < 4) || (argc > 6))
usage();
if (argc > 4)
{
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;
}
if (argc == 6)
{
if (strcmp(argv[5], "NONE"))
{
if (stat(argv[5], &sb))
{
perror(argv[5]);
die("Couldn't stat root device.");
}
major_swap = MAJOR(sb.st_rdev);
minor_swap = MINOR(sb.st_rdev);
}
else
{
major_swap = 0;
minor_swap = 0;
}
}
else
{
major_swap = DEFAULT_MAJOR_SWAP;
minor_swap = DEFAULT_MINOR_SWAP;
}
fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);
fprintf(stderr, "Swap device is (%d, %d)\n", major_swap, minor_swap);
if ((major_root != 2) && (major_root != 3) &&
(major_root != 0))
{
fprintf(stderr, "Illegal root device (major = %d)\n",
major_root);
die("Bad root device --- major #");
}
if (major_swap && major_swap != 3)
{
fprintf(stderr, "Illegal swap device (major = %d)\n",
major_swap);
die("Bad root device --- major #");
}
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] != 0x04100301)
die("Non-Minix header of 'boot'");
if (((long *) buf)[1] != 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)) != 0xAA55)
die("Boot block hasn't got boot flag (0xAA55)");
buf[506] = (char) minor_swap;
buf[507] = (char) major_swap;
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] != 0x04100301)
die("Non-Minix header of 'setup'");
if (((long *) buf)[1] != 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");
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 (((long *) buf)[5] != 0)
die("Non-GCC header of 'system'");
for (i = 0 ; (c = read(id, buf, sizeof buf)) > 0 ; i += c )
if (write(1, buf, c) != c)
die("Write call failed");
close(id);
fprintf(stderr, "System is %d bytes.\n", i);
if (i > SYS_SIZE * 16)
die("System is too big");
return(0);
}
