/* 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#endifstruct 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.__checksummain(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);}