/*	$OpenBSD: mkuboot.c,v 1.1 2010/02/12 17:30:41 mk Exp $	*/

/*
 * Copyright (c) 2008 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <err.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <zlib.h>

#define IH_OS_OPENBSD		1 /* OpenBSD */
#define IH_OS_LINUX		5 /* Linux */

#define IH_ARCH_ALPHA           1       /* Alpha        */
#define IH_ARCH_ARM             2       /* ARM          */
#define IH_ARCH_I386            3       /* Intel x86    */
#define IH_ARCH_IA64            4       /* IA64         */
#define IH_ARCH_MIPS            5       /* MIPS         */
#define IH_ARCH_MIPS64          6       /* MIPS  64 Bit */
#define IH_ARCH_PPC             7       /* PowerPC      */
#define IH_ARCH_SH              9       /* SuperH       */
#define IH_ARCH_SPARC           10      /* Sparc        */
#define IH_ARCH_SPARC64         11      /* Sparc 64 Bit */
#define IH_ARCH_M68K            12      /* M68K         */

#define IH_TYPE_STANDALONE	1 /* Standalone */
#define IH_TYPE_KERNEL		2 /* OS Kernel Image */

#define IH_COMP_NONE		0 /* No compression */

#define IH_MAGIC		0x27051956	/* Image Magic Number */
#define IH_NMLEN		32 		/* Image Name Length */

struct image_header {
	uint32_t	ih_magic;
	uint32_t	ih_hcrc;
	uint32_t	ih_time;
	uint32_t	ih_size;
	uint32_t	ih_load;
	uint32_t	ih_ep;
	uint32_t	ih_dcrc;
	uint8_t		ih_os;
	uint8_t		ih_arch;
	uint8_t		ih_type;
	uint8_t		ih_comp;
	uint8_t		ih_name[IH_NMLEN];
};

extern char *__progname;

void	usage(void);

struct arch_map {
	int id;
	const char *arch;
};

static const struct arch_map archmap[] = {
    { IH_ARCH_ALPHA,	"alpha" },
    { IH_ARCH_IA64,	"amd64" },
    { IH_ARCH_ARM,	"arm" },
    { IH_ARCH_I386,	"i386" },
    { IH_ARCH_M68K,	"m68k" },
    { IH_ARCH_MIPS,	"mips" },
    { IH_ARCH_MIPS64,	"mips64" },
    { IH_ARCH_PPC,	"powerpc" },
    { IH_ARCH_SPARC,	"sparc" },
    { IH_ARCH_SPARC64,	"sparc64" },
    { IH_ARCH_SH,	"superh" },
    { 0, NULL }
};

struct os_map {
	int id;
	const char *arch;
};

static const struct os_map osmap[] = {
    { IH_OS_OPENBSD,	"OpenBSD" },
    { IH_OS_LINUX,	"Linux" },
    { 0, NULL }
};


int
main(int argc, char *argv[])
{
	struct image_header ih;
	const struct arch_map *mapptr;
	const struct os_map *osmapptr;
	const char *iname, *oname;
	const char *arch = MACHINE_ARCH;
	const char *os = "OpenBSD";
	int ifd, ofd;
	u_long crc;
	ssize_t nbytes;
	char buf[BUFSIZ];
	int c, ep, load;

	ep = load = 0;
	while ((c = getopt(argc, argv, "a:e:l:o:")) != -1) {
		switch (c) {
		case 'a':
			arch = optarg;
			break;
		case 'e':
			sscanf(optarg, "0x%x", &ep);
			break;
		case 'l':
			sscanf(optarg, "0x%x", &load);
			break;
		case 'o':
			os = optarg;
			break;
		default:
			usage();
		}
	}

	for (mapptr = archmap; mapptr->arch; mapptr++)
		if (strcasecmp(arch, mapptr->arch) == 0)
			break;

	if (mapptr->arch == NULL) {
		printf("unknown arch '%s'\n", arch);
		usage();
	}

	for (osmapptr = osmap; osmapptr->arch; osmapptr++)
		if (strcasecmp(os, osmapptr->arch) == 0)
			break;

	if (osmapptr->arch == NULL) {
		printf("unknown OS '%s'\n", os);
		usage();
	}

	if (argc - optind != 2)
		usage();

	iname = argv[optind++];
	oname = argv[optind++];

	/* Initialize U-Boot header. */
	bzero(&ih, sizeof ih);
	ih.ih_magic = htobe32(IH_MAGIC);
	ih.ih_time = htobe32(time(NULL));
	ih.ih_load = htobe32(load);
	ih.ih_ep = htobe32(ep);
	ih.ih_os = osmapptr->id;
	ih.ih_arch = mapptr->id;
	ih.ih_type = IH_TYPE_KERNEL;
	ih.ih_comp = IH_COMP_NONE;
	strlcpy(ih.ih_name, "boot", sizeof ih.ih_name);

	ifd = open(iname, O_RDONLY);
	if (ifd < 0)
		err(1, "%s", iname);

	ofd = open(oname, O_RDWR | O_TRUNC | O_CREAT, 0644);
	if (ofd < 0)
		err(1, "%s", oname);

	/* Write initial header. */
	if (write(ofd, &ih, sizeof ih) != sizeof ih)
		err(1, "%s", oname);

	/* Copy data, calculating the data CRC as we go. */
	crc = crc32(0L, Z_NULL, 0);
	while ((nbytes = read(ifd, buf, sizeof buf)) != 0) {
		if (nbytes == -1)
			err(1, "%s", iname);
		if (write(ofd, buf, nbytes) != nbytes)
			err(1, "%s", oname);
		crc = crc32(crc, buf, nbytes);
		ih.ih_size += nbytes;
	}
	ih.ih_dcrc = htobe32(crc);
	ih.ih_size = htobe32(ih.ih_size);

	/* Calculate header CRC. */
	crc = crc32(0, (void *)&ih, sizeof ih);
	ih.ih_hcrc = htobe32(crc);

	/* Write finalized header. */
	if (lseek(ofd, 0, SEEK_SET) != 0)
		err(1, "%s", oname);
	if (write(ofd, &ih, sizeof ih) != sizeof ih)
		err(1, "%s", oname);

	return(0);
}

void
usage(void)
{
	const struct arch_map *mapptr;
	const struct os_map *osmapptr;

	(void)fprintf(stderr,
	    "usage: %s [-a arch] [-e entry] [-l loadaddr] [-o os] "
	    "infile outfile\n", __progname);
	(void)fprintf(stderr,
	    "arch is one of:");
	for (mapptr = archmap; mapptr->arch; mapptr++)
		(void)fprintf(stderr, " %s", mapptr->arch);
	(void)fprintf(stderr, "\n");
	(void)fprintf(stderr,
	    "os is one of:");
	for (osmapptr = osmap; osmapptr->arch; osmapptr++)
		(void)fprintf(stderr, " %s", osmapptr->arch);
	(void)fprintf(stderr, "\n");
	
	exit(1);
}