2 * Makes a Motorola PPCBUG ROM bootable image which can be flashed
3 * into one of the FLASH banks on a Motorola PowerPlus board.
5 * Author: Matt Porter <mporter@mvista.com>
7 * 2001 (c) MontaVista, Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
13 #define ELF_HEADER_SIZE 65536
22 #include <netinet/in.h>
29 /* size of read buffer */
32 /* PPCBUG ROM boot header */
33 typedef struct bug_boot_header {
34 uint8_t magic_word[4]; /* "BOOT" */
35 uint32_t entry_offset; /* Offset from top of header to code */
36 uint32_t routine_length; /* Length of code */
37 uint8_t routine_name[8]; /* Name of the boot code */
40 #define HEADER_SIZE sizeof(bug_boot_header_t)
42 void update_checksum(void *buf, size_t size, uint16_t *sum)
47 csum += *(uint16_t *)buf;
50 buf = (uint16_t *)buf + 1;
56 uint32_t copy_image(int in_fd, int out_fd, uint16_t *sum)
61 uint32_t image_size = 0;
63 lseek(in_fd, ELF_HEADER_SIZE, SEEK_SET);
65 /* Copy an image while recording its size */
66 while ( (n = read(in_fd, buf + offset, SIZE - offset)) > 0 ) {
70 image_size = image_size + n;
71 /* who's going to deal with short writes? */
72 write(out_fd, buf, n);
73 update_checksum(buf, n, sum);
78 /* BUG romboot requires that our size is divisible by 2 */
79 /* align image to 2 byte boundary */
83 write(out_fd, buf, 2);
84 update_checksum(buf, 2, sum);
89 void write_bugboot_header(int out_fd, uint32_t boot_size, uint16_t *sum)
91 static bug_boot_header_t bbh = {
93 .routine_name = "LINUXROM"
96 /* Fill in the PPCBUG ROM boot header */
97 bbh.entry_offset = htonl(HEADER_SIZE); /* Entry address */
98 bbh.routine_length= htonl(HEADER_SIZE+boot_size+2); /* Routine length */
100 /* Output the header and bootloader to the file */
101 write(out_fd, &bbh, sizeof(bug_boot_header_t));
102 update_checksum(&bbh, sizeof(bug_boot_header_t), sum);
105 int main(int argc, char *argv[])
107 int image_fd, bugboot_fd;
108 uint32_t kernel_size = 0;
109 uint16_t checksum = 0;
112 fprintf(stderr, "usage: %s <kernel_image> <bugboot>\n",argv[0]);
118 /* kernel image file */
119 if ((image_fd = open(argv[1] , 0)) < 0)
123 if (!strcmp(argv[2], "-"))
124 bugboot_fd = 1; /* stdout */
125 else if ((bugboot_fd = creat(argv[2] , 0755)) < 0)
128 /* Set file position after ROM header block where zImage will be written */
129 lseek(bugboot_fd, HEADER_SIZE, SEEK_SET);
131 /* Copy kernel image into bugboot image */
132 kernel_size = copy_image(image_fd, bugboot_fd, &checksum);
134 /* Set file position to beginning where header/romboot will be written */
135 lseek(bugboot_fd, 0, SEEK_SET);
137 /* Write out BUG header/romboot */
138 write_bugboot_header(bugboot_fd, kernel_size, &checksum);
140 /* Write out the calculated checksum */
141 lseek(bugboot_fd, 0, SEEK_END);
142 write(bugboot_fd, &checksum, 2);
144 /* Close bugboot file */