1*b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /* This utility makes a bootblock suitable for the SRM console/miniloader */
31da177e4SLinus Torvalds
41da177e4SLinus Torvalds /* Usage:
51da177e4SLinus Torvalds * mkbb <device> <lxboot>
61da177e4SLinus Torvalds *
71da177e4SLinus Torvalds * Where <device> is the name of the device to install the bootblock on,
81da177e4SLinus Torvalds * and <lxboot> is the name of a bootblock to merge in. This bootblock
91da177e4SLinus Torvalds * contains the offset and size of the bootloader. It must be exactly
101da177e4SLinus Torvalds * 512 bytes long.
111da177e4SLinus Torvalds */
121da177e4SLinus Torvalds
131da177e4SLinus Torvalds #include <fcntl.h>
141da177e4SLinus Torvalds #include <unistd.h>
15aeb3f462SMeelis Roos #include <stdlib.h>
161da177e4SLinus Torvalds #include <stdio.h>
171da177e4SLinus Torvalds
181da177e4SLinus Torvalds /* Minimal definition of disklabel, so we don't have to include
191da177e4SLinus Torvalds * asm/disklabel.h (confuses make)
201da177e4SLinus Torvalds */
211da177e4SLinus Torvalds #ifndef MAXPARTITIONS
221da177e4SLinus Torvalds #define MAXPARTITIONS 8 /* max. # of partitions */
231da177e4SLinus Torvalds #endif
241da177e4SLinus Torvalds
251da177e4SLinus Torvalds #ifndef u8
261da177e4SLinus Torvalds #define u8 unsigned char
271da177e4SLinus Torvalds #endif
281da177e4SLinus Torvalds
291da177e4SLinus Torvalds #ifndef u16
301da177e4SLinus Torvalds #define u16 unsigned short
311da177e4SLinus Torvalds #endif
321da177e4SLinus Torvalds
331da177e4SLinus Torvalds #ifndef u32
341da177e4SLinus Torvalds #define u32 unsigned int
351da177e4SLinus Torvalds #endif
361da177e4SLinus Torvalds
371da177e4SLinus Torvalds struct disklabel {
381da177e4SLinus Torvalds u32 d_magic; /* must be DISKLABELMAGIC */
391da177e4SLinus Torvalds u16 d_type, d_subtype;
401da177e4SLinus Torvalds u8 d_typename[16];
411da177e4SLinus Torvalds u8 d_packname[16];
421da177e4SLinus Torvalds u32 d_secsize;
431da177e4SLinus Torvalds u32 d_nsectors;
441da177e4SLinus Torvalds u32 d_ntracks;
451da177e4SLinus Torvalds u32 d_ncylinders;
461da177e4SLinus Torvalds u32 d_secpercyl;
471da177e4SLinus Torvalds u32 d_secprtunit;
481da177e4SLinus Torvalds u16 d_sparespertrack;
491da177e4SLinus Torvalds u16 d_sparespercyl;
501da177e4SLinus Torvalds u32 d_acylinders;
511da177e4SLinus Torvalds u16 d_rpm, d_interleave, d_trackskew, d_cylskew;
521da177e4SLinus Torvalds u32 d_headswitch, d_trkseek, d_flags;
531da177e4SLinus Torvalds u32 d_drivedata[5];
541da177e4SLinus Torvalds u32 d_spare[5];
551da177e4SLinus Torvalds u32 d_magic2; /* must be DISKLABELMAGIC */
561da177e4SLinus Torvalds u16 d_checksum;
571da177e4SLinus Torvalds u16 d_npartitions;
581da177e4SLinus Torvalds u32 d_bbsize, d_sbsize;
591da177e4SLinus Torvalds struct d_partition {
601da177e4SLinus Torvalds u32 p_size;
611da177e4SLinus Torvalds u32 p_offset;
621da177e4SLinus Torvalds u32 p_fsize;
631da177e4SLinus Torvalds u8 p_fstype;
641da177e4SLinus Torvalds u8 p_frag;
651da177e4SLinus Torvalds u16 p_cpg;
661da177e4SLinus Torvalds } d_partitions[MAXPARTITIONS];
671da177e4SLinus Torvalds };
681da177e4SLinus Torvalds
691da177e4SLinus Torvalds
701da177e4SLinus Torvalds typedef union __bootblock {
711da177e4SLinus Torvalds struct {
721da177e4SLinus Torvalds char __pad1[64];
731da177e4SLinus Torvalds struct disklabel __label;
741da177e4SLinus Torvalds } __u1;
751da177e4SLinus Torvalds struct {
761da177e4SLinus Torvalds unsigned long __pad2[63];
771da177e4SLinus Torvalds unsigned long __checksum;
781da177e4SLinus Torvalds } __u2;
791da177e4SLinus Torvalds char bootblock_bytes[512];
801da177e4SLinus Torvalds unsigned long bootblock_quadwords[64];
811da177e4SLinus Torvalds } bootblock;
821da177e4SLinus Torvalds
831da177e4SLinus Torvalds #define bootblock_label __u1.__label
841da177e4SLinus Torvalds #define bootblock_checksum __u2.__checksum
851da177e4SLinus Torvalds
main(int argc,char ** argv)86f8343685SYoann Padioleau int main(int argc, char ** argv)
871da177e4SLinus Torvalds {
881da177e4SLinus Torvalds bootblock bootblock_from_disk;
891da177e4SLinus Torvalds bootblock bootloader_image;
901da177e4SLinus Torvalds int dev, fd;
911da177e4SLinus Torvalds int i;
921da177e4SLinus Torvalds int nread;
931da177e4SLinus Torvalds
941da177e4SLinus Torvalds /* Make sure of the arg count */
951da177e4SLinus Torvalds if(argc != 3) {
961da177e4SLinus Torvalds fprintf(stderr, "Usage: %s device lxboot\n", argv[0]);
971da177e4SLinus Torvalds exit(0);
981da177e4SLinus Torvalds }
991da177e4SLinus Torvalds
1001da177e4SLinus Torvalds /* First, open the device and make sure it's accessible */
1011da177e4SLinus Torvalds dev = open(argv[1], O_RDWR);
1021da177e4SLinus Torvalds if(dev < 0) {
1031da177e4SLinus Torvalds perror(argv[1]);
1041da177e4SLinus Torvalds exit(0);
1051da177e4SLinus Torvalds }
1061da177e4SLinus Torvalds
1071da177e4SLinus Torvalds /* Now open the lxboot and make sure it's reasonable */
1081da177e4SLinus Torvalds fd = open(argv[2], O_RDONLY);
1091da177e4SLinus Torvalds if(fd < 0) {
1101da177e4SLinus Torvalds perror(argv[2]);
1111da177e4SLinus Torvalds close(dev);
1121da177e4SLinus Torvalds exit(0);
1131da177e4SLinus Torvalds }
1141da177e4SLinus Torvalds
1151da177e4SLinus Torvalds /* Read in the lxboot */
1161da177e4SLinus Torvalds nread = read(fd, &bootloader_image, sizeof(bootblock));
1171da177e4SLinus Torvalds if(nread != sizeof(bootblock)) {
1181da177e4SLinus Torvalds perror("lxboot read");
119aeb3f462SMeelis Roos fprintf(stderr, "expected %zd, got %d\n", sizeof(bootblock), nread);
1201da177e4SLinus Torvalds exit(0);
1211da177e4SLinus Torvalds }
1221da177e4SLinus Torvalds
1231da177e4SLinus Torvalds /* Read in the bootblock from disk. */
1241da177e4SLinus Torvalds nread = read(dev, &bootblock_from_disk, sizeof(bootblock));
1251da177e4SLinus Torvalds if(nread != sizeof(bootblock)) {
1261da177e4SLinus Torvalds perror("bootblock read");
127aeb3f462SMeelis Roos fprintf(stderr, "expected %zd, got %d\n", sizeof(bootblock), nread);
1281da177e4SLinus Torvalds exit(0);
1291da177e4SLinus Torvalds }
1301da177e4SLinus Torvalds
1311da177e4SLinus Torvalds /* Swap the bootblock's disklabel into the bootloader */
1321da177e4SLinus Torvalds bootloader_image.bootblock_label = bootblock_from_disk.bootblock_label;
1331da177e4SLinus Torvalds
1341da177e4SLinus Torvalds /* Calculate the bootblock checksum */
1351da177e4SLinus Torvalds bootloader_image.bootblock_checksum = 0;
1361da177e4SLinus Torvalds for(i = 0; i < 63; i++) {
1371da177e4SLinus Torvalds bootloader_image.bootblock_checksum +=
1381da177e4SLinus Torvalds bootloader_image.bootblock_quadwords[i];
1391da177e4SLinus Torvalds }
1401da177e4SLinus Torvalds
1411da177e4SLinus Torvalds /* Write the whole thing out! */
1421da177e4SLinus Torvalds lseek(dev, 0L, SEEK_SET);
1431da177e4SLinus Torvalds if(write(dev, &bootloader_image, sizeof(bootblock)) != sizeof(bootblock)) {
1441da177e4SLinus Torvalds perror("bootblock write");
1451da177e4SLinus Torvalds exit(0);
1461da177e4SLinus Torvalds }
1471da177e4SLinus Torvalds
1481da177e4SLinus Torvalds close(fd);
1491da177e4SLinus Torvalds close(dev);
1501da177e4SLinus Torvalds exit(0);
1511da177e4SLinus Torvalds }
1521da177e4SLinus Torvalds
1531da177e4SLinus Torvalds
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