LXR linux/arch/powerpc/boot/mktree.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Makes a tree bootable image for IBM Evaluation boards.
   4 * Basically, just take a zImage, skip the ELF header, and stuff
   5 * a 32 byte header on the front.
   6 *
   7 * We use htonl, which is a network macro, to make sure we're doing
   8 * The Right Thing on an LE machine.  It's non-obvious, but it should
   9 * work on anything BSD'ish.
  10 */
  11
  12#include <fcntl.h>
  13#include <stdio.h>
  14#include <stdlib.h>
  15#include <string.h>
  16#include <sys/stat.h>
  17#include <unistd.h>
  18#include <netinet/in.h>
  19#ifdef __sun__
  20#include <inttypes.h>
  21#else
  22#include <stdint.h>
  23#endif
  24
  25/* This gets tacked on the front of the image.  There are also a few
  26 * bytes allocated after the _start label used by the boot rom (see
  27 * head.S for details).
  28 */
  29typedef struct boot_block {
  30        uint32_t bb_magic;              /* 0x0052504F */
  31        uint32_t bb_dest;               /* Target address of the image */
  32        uint32_t bb_num_512blocks;      /* Size, rounded-up, in 512 byte blks */
  33        uint32_t bb_debug_flag; /* Run debugger or image after load */
  34        uint32_t bb_entry_point;        /* The image address to start */
  35        uint32_t bb_checksum;   /* 32 bit checksum including header */
  36        uint32_t reserved[2];
  37} boot_block_t;
  38
  39#define IMGBLK  512
  40unsigned int    tmpbuf[IMGBLK / sizeof(unsigned int)];
  41
  42int main(int argc, char *argv[])
  43{
  44        int     in_fd, out_fd;
  45        int     nblks, i;
  46        unsigned int    cksum, *cp;
  47        struct  stat    st;
  48        boot_block_t    bt;
  49
  50        if (argc < 5) {
  51                fprintf(stderr, "usage: %s <zImage-file> <boot-image> <load address> <entry point>\n",argv[0]);
  52                exit(1);
  53        }
  54
  55        if (stat(argv[1], &st) < 0) {
  56                perror("stat");
  57                exit(2);
  58        }
  59
  60        nblks = (st.st_size + IMGBLK) / IMGBLK;
  61
  62        bt.bb_magic = htonl(0x0052504F);
  63
  64        /* If we have the optional entry point parameter, use it */
  65        bt.bb_dest = htonl(strtoul(argv[3], NULL, 0));
  66        bt.bb_entry_point = htonl(strtoul(argv[4], NULL, 0));
  67
  68        /* We know these from the linker command.
  69         * ...and then move it up into memory a little more so the
  70         * relocation can happen.
  71         */
  72        bt.bb_num_512blocks = htonl(nblks);
  73        bt.bb_debug_flag = 0;
  74
  75        bt.bb_checksum = 0;
  76
  77        /* To be neat and tidy :-).
  78        */
  79        bt.reserved[0] = 0;
  80        bt.reserved[1] = 0;
  81
  82        if ((in_fd = open(argv[1], O_RDONLY)) < 0) {
  83                perror("zImage open");
  84                exit(3);
  85        }
  86
  87        if ((out_fd = open(argv[2], (O_RDWR | O_CREAT | O_TRUNC), 0666)) < 0) {
  88                perror("bootfile open");
  89                exit(3);
  90        }
  91
  92        cksum = 0;
  93        cp = (void *)&bt;
  94        for (i = 0; i < sizeof(bt) / sizeof(unsigned int); i++)
  95                cksum += *cp++;
  96
  97        /* Assume zImage is an ELF file, and skip the 64K header.
  98        */
  99        if (read(in_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) {
 100                fprintf(stderr, "%s is too small to be an ELF image\n",
 101                                argv[1]);
 102                exit(4);
 103        }
 104
 105        if (tmpbuf[0] != htonl(0x7f454c46)) {
 106                fprintf(stderr, "%s is not an ELF image\n", argv[1]);
 107                exit(4);
 108        }
 109
 110        if (lseek(in_fd, (64 * 1024), SEEK_SET) < 0) {
 111                fprintf(stderr, "%s failed to seek in ELF image\n", argv[1]);
 112                exit(4);
 113        }
 114
 115        nblks -= (64 * 1024) / IMGBLK;
 116
 117        /* And away we go......
 118        */
 119        if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
 120                perror("boot-image write");
 121                exit(5);
 122        }
 123
 124        while (nblks-- > 0) {
 125                if (read(in_fd, tmpbuf, sizeof(tmpbuf)) < 0) {
 126                        perror("zImage read");
 127                        exit(5);
 128                }
 129                cp = tmpbuf;
 130                for (i = 0; i < sizeof(tmpbuf) / sizeof(unsigned int); i++)
 131                        cksum += *cp++;
 132                if (write(out_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) {
 133                        perror("boot-image write");
 134                        exit(5);
 135                }
 136        }
 137
 138        /* rewrite the header with the computed checksum.
 139        */
 140        bt.bb_checksum = htonl(cksum);
 141        if (lseek(out_fd, 0, SEEK_SET) < 0) {
 142                perror("rewrite seek");
 143                exit(1);
 144        }
 145        if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
 146                perror("boot-image rewrite");
 147                exit(1);
 148        }
 149
 150        exit(0);
 151}
 152