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Diffstat (limited to 'arch/x86_64/boot/tools/build.c')
| -rw-r--r-- | arch/x86_64/boot/tools/build.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/arch/x86_64/boot/tools/build.c b/arch/x86_64/boot/tools/build.c new file mode 100644 index 00000000000..c2fa6631317 --- /dev/null +++ b/arch/x86_64/boot/tools/build.c @@ -0,0 +1,186 @@ +/* + * $Id: build.c,v 1.3 2001/06/26 15:14:50 pavel 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; + /* 0x40000*16 = 4.0 MB, reasonable estimate for the current maximum */ + if (sys_size > (is_big_kernel ? 0x40000 : DEF_SYSSIZE)) + die("System is too big. Try using %smodules.", + is_big_kernel ? "" : "bzImage or "); + 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 */ +} |