LXR linux/arch/ppc/boot/utils/mktree.c

   1/*
   2 * Makes a tree bootable image for IBM Evaluation boards.
   3 * Basically, just take a zImage, skip the ELF header, and stuff
   4 * a 32 byte header on the front.
   5 *
   6 * We use htonl, which is a network macro, to make sure we're doing
   7 * The Right Thing on an LE machine.  It's non-obvious, but it should
   8 * work on anything BSD'ish.
   9 */
  10
  11#include <fcntl.h>
  12#include <stdio.h>
  13#include <stdlib.h>
  14#include <string.h>
  15#include <sys/stat.h>
  16#include <unistd.h>
  17#include <netinet/in.h>
  18#ifdef __sun__
  19#include <inttypes.h>
  20#else
  21#include <stdint.h>
  22#endif
  23
  24/* This gets tacked on the front of the image.  There are also a few
  25 * bytes allocated after the _start label used by the boot rom (see
  26 * head.S for details).
  27 */
  28typedef struct boot_block {
  29        uint32_t bb_magic;              /* 0x0052504F */
  30        uint32_t bb_dest;               /* Target address of the image */
  31        uint32_t bb_num_512blocks;      /* Size, rounded-up, in 512 byte blks */
  32        uint32_t bb_debug_flag; /* Run debugger or image after load */
  33        uint32_t bb_entry_point;        /* The image address to start */
  34        uint32_t bb_checksum;   /* 32 bit checksum including header */
  35        uint32_t reserved[2];
  36} boot_block_t;
  37
  38#define IMGBLK  512
  39char    tmpbuf[IMGBLK];
  40
  41int main(int argc, char *argv[])
  42{
  43        int     in_fd, out_fd;
  44        int     nblks, i;
  45        uint    cksum, *cp;
  46        struct  stat    st;
  47        boot_block_t    bt;
  48
  49        if (argc < 3) {
  50                fprintf(stderr, "usage: %s <zImage-file> <boot-image> [entry-point]\n",argv[0]);
  51                exit(1);
  52        }
  53
  54        if (stat(argv[1], &st) < 0) {
  55                perror("stat");
  56                exit(2);
  57        }
  58
  59        nblks = (st.st_size + IMGBLK) / IMGBLK;
  60
  61        bt.bb_magic = htonl(0x0052504F);
  62
  63        /* If we have the optional entry point parameter, use it */
  64        if (argc == 4)
  65                bt.bb_dest = bt.bb_entry_point = htonl(strtoul(argv[3], NULL, 0));
  66        else
  67                bt.bb_dest = bt.bb_entry_point = htonl(0x500000);
  68
  69        /* We know these from the linker command.
  70         * ...and then move it up into memory a little more so the
  71         * relocation can happen.
  72         */
  73        bt.bb_num_512blocks = htonl(nblks);
  74        bt.bb_debug_flag = 0;
  75
  76        bt.bb_checksum = 0;
  77
  78        /* To be neat and tidy :-).
  79        */
  80        bt.reserved[0] = 0;
  81        bt.reserved[1] = 0;
  82
  83        if ((in_fd = open(argv[1], O_RDONLY)) < 0) {
  84                perror("zImage open");
  85                exit(3);
  86        }
  87
  88        if ((out_fd = open(argv[2], (O_RDWR | O_CREAT | O_TRUNC), 0666)) < 0) {
  89                perror("bootfile open");
  90                exit(3);
  91        }
  92
  93        cksum = 0;
  94        cp = (void *)&bt;
  95        for (i=0; i<sizeof(bt)/sizeof(uint); i++)
  96                cksum += *cp++;
  97        
  98        /* Assume zImage is an ELF file, and skip the 64K header.
  99        */
 100        if (read(in_fd, tmpbuf, IMGBLK) != IMGBLK) {
 101                fprintf(stderr, "%s is too small to be an ELF image\n",
 102                                argv[1]);
 103                exit(4);
 104        }
 105
 106        if ((*(uint *)tmpbuf) != htonl(0x7f454c46)) {
 107                fprintf(stderr, "%s is not an ELF image\n", argv[1]);
 108                exit(4);
 109        }
 110
 111        if (lseek(in_fd, (64 * 1024), SEEK_SET) < 0) {
 112                fprintf(stderr, "%s failed to seek in ELF image\n", argv[1]);
 113                exit(4);
 114        }
 115
 116        nblks -= (64 * 1024) / IMGBLK;
 117
 118        /* And away we go......
 119        */
 120        if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
 121                perror("boot-image write");
 122                exit(5);
 123        }
 124
 125        while (nblks-- > 0) {
 126                if (read(in_fd, tmpbuf, IMGBLK) < 0) {
 127                        perror("zImage read");
 128                        exit(5);
 129                }
 130                cp = (uint *)tmpbuf;
 131                for (i=0; i<sizeof(tmpbuf)/sizeof(uint); i++)
 132                        cksum += *cp++;
 133                if (write(out_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) {
 134                        perror("boot-image write");
 135                        exit(5);
 136                }
 137        }
 138
 139        /* rewrite the header with the computed checksum.
 140        */
 141        bt.bb_checksum = htonl(cksum);
 142        if (lseek(out_fd, 0, SEEK_SET) < 0) {
 143                perror("rewrite seek");
 144                exit(1);
 145        }
 146        if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
 147                perror("boot-image rewrite");
 148                exit(1);
 149        }
 150
 151        exit(0);
 152}
 153