diff options
Diffstat (limited to 'arch/alpha/boot/tools/mkbb.c')
-rw-r--r-- | arch/alpha/boot/tools/mkbb.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/alpha/boot/tools/mkbb.c b/arch/alpha/boot/tools/mkbb.c new file mode 100644 index 000000000..fc47f33f8 --- /dev/null +++ b/arch/alpha/boot/tools/mkbb.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0 +/* 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 <stdlib.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 + +int 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 %zd, 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 %zd, 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); +} + + |