diff options
Diffstat (limited to 'arch/x86/boot/tools/build.c')
| -rw-r--r-- | arch/x86/boot/tools/build.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c new file mode 100644 index 000000000000..b4248740ff0d --- /dev/null +++ b/arch/x86/boot/tools/build.c @@ -0,0 +1,168 @@ +/* + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright (C) 1997 Martin Mares + * Copyright (C) 2007 H. Peter Anvin + */ + +/* + * This file builds a disk-image from two different files: + * + * - 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 + * Substantially overhauled by H. Peter Anvin, April 2007 + */ + +#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 <sys/mman.h> +#include <asm/boot.h> + +typedef unsigned char u8; +typedef unsigned short u16; +typedef unsigned long u32; + +#define DEFAULT_MAJOR_ROOT 0 +#define DEFAULT_MINOR_ROOT 0 + +/* Minimal number of setup sectors */ +#define SETUP_SECT_MIN 5 +#define SETUP_SECT_MAX 64 + +/* This must be large enough to hold the entire setup */ +u8 buf[SETUP_SECT_MAX*512]; +int is_big_kernel; + +static void die(const char * str, ...) +{ + va_list args; + va_start(args, str); + vfprintf(stderr, str, args); + fputc('\n', stderr); + exit(1); +} + +static void usage(void) +{ + die("Usage: build [-b] setup system [rootdev] [> image]"); +} + +int main(int argc, char ** argv) +{ + unsigned int i, sz, setup_sectors; + int c; + u32 sys_size; + u8 major_root, minor_root; + struct stat sb; + FILE *file; + int fd; + void *kernel; + + if (argc > 2 && !strcmp(argv[1], "-b")) + { + is_big_kernel = 1; + argc--, argv++; + } + if ((argc < 3) || (argc > 4)) + usage(); + if (argc > 3) { + if (!strcmp(argv[3], "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[3], "FLOPPY")) { + if (stat(argv[3], &sb)) { + perror(argv[3]); + 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); + + /* Copy the setup code */ + file = fopen(argv[1], "r"); + if (!file) + die("Unable to open `%s': %m", argv[1]); + c = fread(buf, 1, sizeof(buf), file); + if (ferror(file)) + die("read-error on `setup'"); + if (c < 1024) + die("The setup must be at least 1024 bytes"); + if (buf[510] != 0x55 || buf[511] != 0xaa) + die("Boot block hasn't got boot flag (0xAA55)"); + fclose(file); + + /* Pad unused space with zeros */ + setup_sectors = (c + 511) / 512; + if (setup_sectors < SETUP_SECT_MIN) + setup_sectors = SETUP_SECT_MIN; + i = setup_sectors*512; + memset(buf+c, 0, i-c); + + /* Set the default root device */ + buf[508] = minor_root; + buf[509] = major_root; + + fprintf(stderr, "Setup is %d bytes (padded to %d bytes).\n", c, i); + + /* Open and stat the kernel file */ + fd = open(argv[2], O_RDONLY); + if (fd < 0) + die("Unable to open `%s': %m", argv[2]); + if (fstat(fd, &sb)) + die("Unable to stat `%s': %m", argv[2]); + sz = sb.st_size; + fprintf (stderr, "System is %d kB\n", (sz+1023)/1024); + kernel = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0); + if (kernel == MAP_FAILED) + die("Unable to mmap '%s': %m", argv[2]); + sys_size = (sz + 15) / 16; + if (!is_big_kernel && sys_size > DEF_SYSSIZE) + die("System is too big. Try using bzImage or modules."); + + /* Patch the setup code with the appropriate size parameters */ + buf[0x1f1] = setup_sectors-1; + buf[0x1f4] = sys_size; + buf[0x1f5] = sys_size >> 8; + buf[0x1f6] = sys_size >> 16; + buf[0x1f7] = sys_size >> 24; + + if (fwrite(buf, 1, i, stdout) != i) + die("Writing setup failed"); + + /* Copy the kernel code */ + if (fwrite(kernel, 1, sz, stdout) != sz) + die("Writing kernel failed"); + close(fd); + + /* Everything is OK */ + return 0; +} |