Subversion Repositories or1k

/*

 *  $Id: build.c,v 1.1.1.1 2004-04-15 01:36:30 phoenix Exp $

 *

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *  Copyright (C) 1997 Martin Mares

 */

/*

 * This file builds a disk-image from three different files:

 *

 * - bootsect: exactly 512 bytes of 8086 machine code, loads the rest

 * - setup: 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

 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996

 * Cross compiling fixes by Gertjan van Wingerde, July 1996

 * Rewritten by Martin Mares, April 1997

 */

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <stdarg.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/sysmacros.h>

#include <unistd.h>

#include <fcntl.h>

#include <asm/boot.h>

typedef unsigned char byte;

typedef unsigned short word;

typedef unsigned long u32;

#define DEFAULT_MAJOR_ROOT 0

#define DEFAULT_MINOR_ROOT 0

/* Minimal number of setup sectors (see also bootsect.S) */

#define SETUP_SECTS 4

byte buf[1024];

int fd;

int is_big_kernel;

void die(const char * str, ...)

{

        va_list args;

        va_start(args, str);

        vfprintf(stderr, str, args);

        fputc('\n', stderr);

        exit(1);

}

void file_open(const char *name)

{

        if ((fd = open(name, O_RDONLY, 0)) < 0)

                die("Unable to open `%s': %m", name);

}

void usage(void)

{

        die("Usage: build [-b] bootsect setup system [rootdev] [> image]");

}

int main(int argc, char ** argv)

{

        unsigned int i, c, sz, setup_sectors;

        u32 sys_size;

        byte major_root, minor_root;

        struct stat sb;

        if (argc > 2 && !strcmp(argv[1], "-b"))

          {

            is_big_kernel = 1;

            argc--, argv++;

          }

        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);

        file_open(argv[1]);

        i = read(fd, buf, sizeof(buf));

        fprintf(stderr,"Boot sector %d bytes.\n",i);

        if (i != 512)

                die("Boot block must be exactly 512 bytes");

        if (buf[510] != 0x55 || buf[511] != 0xaa)

                die("Boot block hasn't got boot flag (0xAA55)");

        buf[508] = minor_root;

        buf[509] = major_root;

        if (write(1, buf, 512) != 512)

                die("Write call failed");

        close (fd);

        file_open(argv[2]);                                 /* Copy the setup code */

        for (i=0 ; (c=read(fd, 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 (fd);

        setup_sectors = (i + 511) / 512;        /* Pad unused space with zeros */

        /* for compatibility with ancient versions of LILO. */

        if (setup_sectors < SETUP_SECTS)

                setup_sectors = SETUP_SECTS;

        fprintf(stderr, "Setup is %d bytes.\n", i);

        memset(buf, 0, sizeof(buf));

        while (i < setup_sectors * 512) {

                c = setup_sectors * 512 - i;

                if (c > sizeof(buf))

                        c = sizeof(buf);

                if (write(1, buf, c) != c)

                        die("Write call failed");

                i += c;

        }

        file_open(argv[3]);

        if (fstat (fd, &sb))

                die("Unable to stat `%s': %m", argv[3]);

        sz = sb.st_size;

        fprintf (stderr, "System is %d kB\n", sz/1024);

        sys_size = (sz + 15) / 16;

        /* 0x28000*16 = 2.5 MB, conservative estimate for the current maximum */

        if (sys_size > (is_big_kernel ? 0x28000 : DEF_SYSSIZE))

                die("System is too big. Try using %smodules.",

                        is_big_kernel ? "" : "bzImage or ");

        if (sys_size > 0xefff)

                fprintf(stderr,"warning: kernel is too big for standalone boot "

                    "from floppy\n");

        while (sz > 0) {

                int l, n;

                l = (sz > sizeof(buf)) ? sizeof(buf) : sz;

                if ((n=read(fd, buf, l)) != l) {

                        if (n < 0)

                                die("Error reading %s: %m", argv[3]);

                        else

                                die("%s: Unexpected EOF", argv[3]);

                }

                if (write(1, buf, l) != l)

                        die("Write failed");

                sz -= l;

        }

        close(fd);

        if (lseek(1, 497, SEEK_SET) != 497)                 /* Write sizes to the bootsector */

                die("Output: seek failed");

        buf[0] = setup_sectors;

        if (write(1, buf, 1) != 1)

                die("Write of setup sector count failed");

        if (lseek(1, 500, SEEK_SET) != 500)

                die("Output: seek failed");

        buf[0] = (sys_size & 0xff);

        buf[1] = ((sys_size >> 8) & 0xff);

        if (write(1, buf, 2) != 2)

                die("Write of image length failed");

        return 0;                                            /* Everything is OK */

}