--- /dev/null
+/*
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright (C) 1997 Martin Mares
+ */
+
+/*
+ * This file builds a disk-image from three different files:
+ *
+ * - bootsect: Compatibility mbr which prints an error message if
+ * someone tries to boot the kernel directly.
+ * - setup: 8086 machine code, sets up system parm
+ * - vmlwk.bin: The "piggy" LWK kernel image. The first part of the
+ * image is the decompression code (compressed/head.o),
+ * which begins executing at startup_32. startup_32 then
+ * uncompresses the real kernel image that follows it.
+ *
+ * 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);
+ buf[2] = ((sys_size >> 16) & 0xff);
+ buf[3] = ((sys_size >> 24) & 0xff);
+ if (write(1, buf, 4) != 4)
+ die("Write of image length failed");
+
+ return 0; /* Everything is OK */
+}
