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.
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.
17 #include <netinet/in.h>
19 /* This gets tacked on the front of the image. There are also a few
20 * bytes allocated after the _start label used by the boot rom (see
21 * head.S for details).
23 typedef struct boot_block {
24 unsigned long bb_magic; /* 0x0052504F */
25 unsigned long bb_dest; /* Target address of the image */
26 unsigned long bb_num_512blocks; /* Size, rounded-up, in 512 byte blks */
27 unsigned long bb_debug_flag; /* Run debugger or image after load */
28 unsigned long bb_entry_point; /* The image address to start */
29 unsigned long bb_checksum; /* 32 bit checksum including header */
30 unsigned long reserved[2];
36 int main(int argc, char *argv[])
45 fprintf(stderr, "usage: %s <zImage-file> <boot-image> [entry-point]\n",argv[0]);
49 if (stat(argv[1], &st) < 0) {
54 nblks = (st.st_size + IMGBLK) / IMGBLK;
56 bt.bb_magic = htonl(0x0052504F);
58 /* If we have the optional entry point parameter, use it */
60 bt.bb_dest = bt.bb_entry_point = htonl(strtoul(argv[3], NULL, 0));
62 bt.bb_dest = bt.bb_entry_point = htonl(0x500000);
64 /* We know these from the linker command.
65 * ...and then move it up into memory a little more so the
66 * relocation can happen.
68 bt.bb_num_512blocks = htonl(nblks);
73 /* To be neat and tidy :-).
78 if ((in_fd = open(argv[1], O_RDONLY)) < 0) {
79 perror("zImage open");
83 if ((out_fd = open(argv[2], (O_RDWR | O_CREAT | O_TRUNC), 0666)) < 0) {
84 perror("bootfile open");
90 for (i=0; i<sizeof(bt)/sizeof(uint); i++)
93 /* Assume zImage is an ELF file, and skip the 64K header.
95 if (read(in_fd, tmpbuf, IMGBLK) != IMGBLK) {
96 fprintf(stderr, "%s is too small to be an ELF image\n",
101 if ((*(uint *)tmpbuf) != htonl(0x7f454c46)) {
102 fprintf(stderr, "%s is not an ELF image\n", argv[1]);
106 if (lseek(in_fd, (64 * 1024), SEEK_SET) < 0) {
107 fprintf(stderr, "%s failed to seek in ELF image\n", argv[1]);
111 nblks -= (64 * 1024) / IMGBLK;
113 /* And away we go......
115 if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
116 perror("boot-image write");
120 while (nblks-- > 0) {
121 if (read(in_fd, tmpbuf, IMGBLK) < 0) {
122 perror("zImage read");
126 for (i=0; i<sizeof(tmpbuf)/sizeof(uint); i++)
128 if (write(out_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) {
129 perror("boot-image write");
134 /* rewrite the header with the computed checksum.
136 bt.bb_checksum = htonl(cksum);
137 if (lseek(out_fd, 0, SEEK_SET) < 0) {
138 perror("rewrite seek");
141 if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) {
142 perror("boot-image rewrite");