patch-1.3.75 linux/arch/alpha/boot/tools/mkbb.c

• Lines: 152
• Date: Sat Mar 16 13:52:12 1996
• Orig file: v1.3.74/linux/arch/alpha/boot/tools/mkbb.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.74/linux/arch/alpha/boot/tools/mkbb.c linux/arch/alpha/boot/tools/mkbb.c
@@ -0,0 +1,151 @@
+/* This utility makes a bootblock suitable for the SRM console/miniloader */
+
+/* Usage:
+ *	mkbb <device> <lxboot>
+ *
+ * Where <device> is the name of the device to install the bootblock on,
+ * and <lxboot> is the name of a bootblock to merge in.  This bootblock
+ * contains the offset and size of the bootloader.  It must be exactly
+ * 512 bytes long.
+ */
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+
+/* Minimal definition of disklabel, so we don't have to include
+ * asm/disklabel.h (confuses make)
+ */
+#ifndef MAXPARTITIONS
+#define MAXPARTITIONS   8                       /* max. # of partitions */
+#endif
+
+#ifndef u8
+#define u8 unsigned char
+#endif
+
+#ifndef u16
+#define u16 unsigned short
+#endif
+
+#ifndef u32
+#define u32 unsigned int
+#endif
+
+struct disklabel {
+    u32	d_magic;				/* must be DISKLABELMAGIC */
+    u16	d_type, d_subtype;
+    u8	d_typename[16];
+    u8	d_packname[16];
+    u32	d_secsize;
+    u32	d_nsectors;
+    u32	d_ntracks;
+    u32	d_ncylinders;
+    u32	d_secpercyl;
+    u32	d_secprtunit;
+    u16	d_sparespertrack;
+    u16	d_sparespercyl;
+    u32	d_acylinders;
+    u16	d_rpm, d_interleave, d_trackskew, d_cylskew;
+    u32	d_headswitch, d_trkseek, d_flags;
+    u32	d_drivedata[5];
+    u32	d_spare[5];
+    u32	d_magic2;				/* must be DISKLABELMAGIC */
+    u16	d_checksum;
+    u16	d_npartitions;
+    u32	d_bbsize, d_sbsize;
+    struct d_partition {
+	u32	p_size;
+	u32	p_offset;
+	u32	p_fsize;
+	u8	p_fstype;
+	u8	p_frag;
+	u16	p_cpg;
+    } d_partitions[MAXPARTITIONS];
+};
+
+
+typedef union __bootblock {
+    struct {
+        char			__pad1[64];
+        struct disklabel	__label;
+    } __u1;
+    struct {
+	unsigned long		__pad2[63];
+	unsigned long		__checksum;
+    } __u2;
+    char		bootblock_bytes[512];
+    unsigned long	bootblock_quadwords[64];
+} bootblock;
+
+#define	bootblock_label		__u1.__label
+#define bootblock_checksum	__u2.__checksum
+
+main(int argc, char ** argv)
+{
+    bootblock		bootblock_from_disk;
+    bootblock		bootloader_image;
+    int			dev, fd;
+    int			i;
+    int			nread;
+
+    /* Make sure of the arg count */
+    if(argc != 3) {
+	fprintf(stderr, "Usage: %s device lxboot\n", argv[0]);
+	exit(0);
+    }
+
+    /* First, open the device and make sure it's accessible */
+    dev = open(argv[1], O_RDWR);
+    if(dev < 0) {
+	perror(argv[1]);
+	exit(0);
+    }
+
+    /* Now open the lxboot and make sure it's reasonable */
+    fd = open(argv[2], O_RDONLY);
+    if(fd < 0) {
+	perror(argv[2]);
+	close(dev);
+	exit(0);
+    }
+
+    /* Read in the lxboot */
+    nread = read(fd, &bootloader_image, sizeof(bootblock));
+    if(nread != sizeof(bootblock)) {
+	perror("lxboot read");
+	fprintf(stderr, "expected %d, got %d\n", sizeof(bootblock), nread);
+	exit(0);
+    }
+
+    /* Read in the bootblock from disk. */
+    nread = read(dev, &bootblock_from_disk, sizeof(bootblock));
+    if(nread != sizeof(bootblock)) {
+	perror("bootblock read");
+	fprintf(stderr, "expected %d, got %d\n", sizeof(bootblock), nread);
+	exit(0);
+    }
+
+    /* Swap the bootblock's disklabel into the bootloader */
+    bootloader_image.bootblock_label = bootblock_from_disk.bootblock_label;
+
+    /* Calculate the bootblock checksum */
+    bootloader_image.bootblock_checksum = 0;
+    for(i = 0; i < 63; i++) {
+	bootloader_image.bootblock_checksum += 
+			bootloader_image.bootblock_quadwords[i];
+    }
+
+    /* Write the whole thing out! */
+    lseek(dev, 0L, SEEK_SET);
+    if(write(dev, &bootloader_image, sizeof(bootblock)) != sizeof(bootblock)) {
+	perror("bootblock write");
+	exit(0);
+    }
+
+    close(fd);
+    close(dev);
+    exit(0);
+}
+
+