util/cbfstool/cbfs-mkpayload.c

/*
 * cbfs-mkpayload
 *
 * Copyright (C) 2008 Jordan Crouse <jordan@cosmicpenguin.net>
 *               2009 coresystems GmbH
 *                 written by Patrick Georgi <patrick.georgi@coresystems.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "elf.h"
#include <fcntl.h>
#include <getopt.h>
#include <sys/stat.h>

#include "common.h"
#include "cbfs.h"

int parse_elf_to_payload(unsigned char *input, unsigned char **output,
			 comp_algo algo)
{
	Elf32_Phdr *phdr;
	Elf32_Ehdr *ehdr;
	Elf32_Shdr *shdr;
	char *header;
	char *strtab;
	unsigned char *sptr;
	int headers;
	int segments = 1;
	int isize = 0, osize = 0;
	int doffset = 0;
	struct cbfs_payload_segment *segs;
	int i;

	if(!iself(input)){
		printf("Fatal error: the payload file is not in ELF format!\n");
		exit(1);
	}


	comp_func_ptr compress = compression_function(algo);
	if (!compress)
		return -1;

	ehdr = (Elf32_Ehdr *) input;
	headers = ehdr->e_phnum;
	header = (char *)ehdr;

	phdr = (Elf32_Phdr *) & (header[ehdr->e_phoff]);
	shdr = (Elf32_Shdr *) & (header[ehdr->e_shoff]);

	strtab = &header[shdr[ehdr->e_shstrndx].sh_offset];

	/* Count the number of headers - look for the .notes.pinfo
	 * section */

	for (i = 0; i < ehdr->e_shnum; i++) {
		char *name;

		if (i == ehdr->e_shstrndx)
			continue;

		if (shdr[i].sh_size == 0)
			continue;

		name = (char *)(strtab + shdr[i].sh_name);

		if (!strcmp(name, ".note.pinfo")) {
			segments++;
			isize += (unsigned int)shdr[i].sh_size;
		}
	}

	/* Now, regular headers - we only care about PT_LOAD headers,
	 * because thats what we're actually going to load
	 */

	for (i = 0; i < headers; i++) {
		if (phdr[i].p_type != PT_LOAD)
			continue;

		/* Empty segments are never interesting */
		if (phdr[i].p_memsz == 0)
			continue;

		isize += phdr[i].p_filesz;

		segments++;
	}

	/* Allocate a block of memory to store the data in */

	sptr =
	    calloc((segments * sizeof(struct cbfs_payload_segment)) + isize, 1);
	doffset = (segments * sizeof(struct cbfs_payload_segment));

	if (sptr == NULL)
		goto err;

	segs = (struct cbfs_payload_segment *)sptr;
	segments = 0;

	for (i = 0; i < ehdr->e_shnum; i++) {
		char *name;

		if (i == ehdr->e_shstrndx)
			continue;

		if (shdr[i].sh_size == 0)
			continue;

		name = (char *)(strtab + shdr[i].sh_name);

		if (!strcmp(name, ".note.pinfo")) {
			segs[segments].type = PAYLOAD_SEGMENT_PARAMS;
			segs[segments].load_addr = 0;
			segs[segments].len = (unsigned int)shdr[i].sh_size;
			segs[segments].offset = doffset;

			memcpy((unsigned long *)(sptr + doffset),
			       &header[shdr[i].sh_offset], shdr[i].sh_size);

			doffset += segs[segments].len;
			osize += segs[segments].len;

			segments++;
		}
	}

	for (i = 0; i < headers; i++) {
		if (phdr[i].p_type != PT_LOAD)
			continue;

		if (phdr[i].p_memsz == 0)
			continue;

		if (phdr[i].p_filesz == 0) {
			segs[segments].type = PAYLOAD_SEGMENT_BSS;
			segs[segments].load_addr =
			    (unsigned long long)htonl(phdr[i].p_paddr);
			segs[segments].mem_len =
			    (unsigned int)htonl(phdr[i].p_memsz);
			segs[segments].offset = htonl(doffset);

			segments++;
			continue;
		}

		if (phdr[i].p_flags & PF_X)
			segs[segments].type = PAYLOAD_SEGMENT_CODE;
		else
			segs[segments].type = PAYLOAD_SEGMENT_DATA;
		segs[segments].load_addr = (unsigned int)htonl(phdr[i].p_paddr);
		segs[segments].mem_len = (unsigned int)htonl(phdr[i].p_memsz);
		segs[segments].compression = htonl(algo);
		segs[segments].offset = htonl(doffset);

		int len;
		compress((char *)&header[phdr[i].p_offset],
			 phdr[i].p_filesz, (char *)(sptr + doffset), &len);
		segs[segments].len = htonl(len);

		/* If the compressed section is larger, then use the
		   original stuff */

		if ((unsigned int)len > phdr[i].p_filesz) {
			segs[segments].compression = 0;
			segs[segments].len = htonl(phdr[i].p_filesz);

			memcpy((char *)(sptr + doffset),
			       &header[phdr[i].p_offset], phdr[i].p_filesz);
		}

		doffset += ntohl(segs[segments].len);
		osize += ntohl(segs[segments].len);

		segments++;
	}

	segs[segments].type = PAYLOAD_SEGMENT_ENTRY;
	segs[segments++].load_addr = (unsigned long long)htonl(ehdr->e_entry);

	*output = sptr;

	return (segments * sizeof(struct cbfs_payload_segment)) + osize;

      err:
	return -1;
}