/* * 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;}