/*
* Makes a Motorola PPCBUG ROM bootable image which can be flashed
* into one of the FLASH banks on a Motorola PowerPlus board.
*
* Author: Matt Porter <mporter@mvista.com>
*
* 2001 (c) MontaVista, Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#define ELF_HEADER_SIZE 65536
#include <unistd.h>
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#ifdef __sun__
#include <inttypes.h>
#else
#include <stdint.h>
#endif
/* size of read buffer */
#define SIZE 0x1000
/* PPCBUG ROM boot header */
typedef struct bug_boot_header {
uint8_t magic_word[4]; /* "BOOT" */
uint32_t entry_offset; /* Offset from top of header to code */
uint32_t routine_length; /* Length of code */
uint8_t routine_name[8]; /* Name of the boot code */
} bug_boot_header_t;
#define HEADER_SIZE sizeof(bug_boot_header_t)
void update_checksum(void *buf, size_t size, uint16_t *sum)
{
uint32_t csum = *sum;
while (size) {
csum += *(uint16_t *)buf;
if (csum > 0xffff)
csum -= 0xffff;
buf = (uint16_t *)buf + 1;
size -= 2;
}
*sum = csum;
}
uint32_t copy_image(int in_fd, int out_fd, uint16_t *sum)
{
uint8_t buf[SIZE];
int offset = 0;
int n;
uint32_t image_size = 0;
lseek(in_fd, ELF_HEADER_SIZE, SEEK_SET);
/* Copy an image while recording its size */
while ( (n = read(in_fd, buf + offset, SIZE - offset)) > 0 ) {
n += offset;
offset = n & 1;
n -= offset;
image_size = image_size + n;
/* who's going to deal with short writes? */
write(out_fd, buf, n);
update_checksum(buf, n, sum);
if (offset)
buf[0] = buf[n];
}
/* BUG romboot requires that our size is divisible by 2 */
/* align image to 2 byte boundary */
if (offset) {
image_size += 2;
buf[1] = '\0';
write(out_fd, buf, 2);
update_checksum(buf, 2, sum);
}
return image_size;
}
void write_bugboot_header(int out_fd, uint32_t boot_size, uint16_t *sum)
{
static bug_boot_header_t bbh = {
.magic_word = "BOOT",
.routine_name = "LINUXROM"
};
/* Fill in the PPCBUG ROM boot header */
bbh.entry_offset = htonl(HEADER_SIZE); /* Entry address */
bbh.routine_length= htonl(HEADER_SIZE+boot_size+2); /* Routine length */
/* Output the header and bootloader to the file */
write(out_fd, &bbh, sizeof(bug_boot_header_t));
update_checksum(&bbh, sizeof(bug_boot_header_t), sum);
}
int main(int argc, char *argv[])
{
int image_fd, bugboot_fd;
uint32_t kernel_size = 0;
uint16_t checksum = 0;
if (argc != 3) {
fprintf(stderr, "usage: %s <kernel_image> <bugboot>\n",argv[0]);
exit(-1);
}
/* Get file args */
/* kernel image file */
if ((image_fd = open(argv[1] , 0)) < 0)
exit(-1);
/* bugboot file */
if (!strcmp(argv[2], "-"))
bugboot_fd = 1; /* stdout */
else if ((bugboot_fd = creat(argv[2] , 0755)) < 0)
exit(-1);
/* Set file position after ROM header block where zImage will be written */
lseek(bugboot_fd, HEADER_SIZE, SEEK_SET);
/* Copy kernel image into bugboot image */
kernel_size = copy_image(image_fd, bugboot_fd, &checksum);
/* Set file position to beginning where header/romboot will be written */
lseek(bugboot_fd, 0, SEEK_SET);
/* Write out BUG header/romboot */
write_bugboot_header(bugboot_fd, kernel_size, &checksum);
/* Write out the calculated checksum */
lseek(bugboot_fd, 0, SEEK_END);
write(bugboot_fd, &checksum, 2);
/* Close bugboot file */
close(bugboot_fd);
return 0;
}
