tools/sunxi-spl-image-builder.c - uboot-imx - Git at Google

 /*
  * Allwinner NAND randomizer and image builder implementation:
  *
  * Copyright © 2016 NextThing Co.
  * Copyright © 2016 Free Electrons
  *
  * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
  *
  */

 #include <linux/bch.h>

 #include <getopt.h>
 #include <version.h>

 #define BCH_PRIMITIVE_POLY	0x5803

 #define ARRAY_SIZE(arr)		(sizeof(arr) / sizeof((arr)[0]))
 #define DIV_ROUND_UP(n,d)	(((n) + (d) - 1) / (d))

 struct image_info {
 	int ecc_strength;
 	int ecc_step_size;
 	int page_size;
 	int oob_size;
 	int usable_page_size;
 	int eraseblock_size;
 	int scramble;
 	int boot0;
 	off_t offset;
 	const char *source;
 	const char *dest;
 };

 static void swap_bits(uint8_t *buf, int len)
 {
 	int i, j;

 	for (j = 0; j < len; j++) {
 		uint8_t byte = buf[j];

 		buf[j] = 0;
 		for (i = 0; i < 8; i++) {
 			if (byte & (1 << i))
 				buf[j] |= (1 << (7 - i));
 		}
 	}
 }

 static uint16_t lfsr_step(uint16_t state, int count)
 {
 	state &= 0x7fff;
 	while (count--)
 		state = ((state >> 1) |
 			 ((((state >> 0) ^ (state >> 1)) & 1) << 14)) & 0x7fff;

 	return state;
 }

 static uint16_t default_scrambler_seeds[] = {
 	0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
 	0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
 	0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
 	0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
 	0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
 	0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
 	0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
 	0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
 	0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
 	0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
 	0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
 	0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
 	0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
 	0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
 	0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
 	0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
 };

 static uint16_t brom_scrambler_seeds[] = { 0x4a80 };

 static void scramble(const struct image_info *info,
 		     int page, uint8_t *data, int datalen)
 {
 	uint16_t state;
 	int i;

 	/* Boot0 is always scrambled no matter the command line option. */
 	if (info->boot0) {
 		state = brom_scrambler_seeds[0];
 	} else {
 		unsigned seedmod = info->eraseblock_size / info->page_size;

 		/* Bail out earlier if the user didn't ask for scrambling. */
 		if (!info->scramble)
 			return;

 		if (seedmod > ARRAY_SIZE(default_scrambler_seeds))
 			seedmod = ARRAY_SIZE(default_scrambler_seeds);

 		state = default_scrambler_seeds[page % seedmod];
 	}

 	/* Prepare the initial state... */
 	state = lfsr_step(state, 15);

 	/* and start scrambling data. */
 	for (i = 0; i < datalen; i++) {
 		data[i] ^= state;
 		state = lfsr_step(state, 8);
 	}
 }

 static int write_page(const struct image_info *info, uint8_t *buffer,
 		      FILE *src, FILE *rnd, FILE *dst,
 		      struct bch_control *bch, int page)
 {
 	int steps = info->usable_page_size / info->ecc_step_size;
 	int eccbytes = DIV_ROUND_UP(info->ecc_strength * 14, 8);
 	off_t pos = ftell(dst);
 	size_t pad, cnt;
 	int i;

 	if (eccbytes % 2)
 		eccbytes++;

 	memset(buffer, 0xff, info->page_size + info->oob_size);
 	cnt = fread(buffer, 1, info->usable_page_size, src);
 	if (!cnt) {
 		if (!feof(src)) {
 			fprintf(stderr,
 				"Failed to read data from the source\n");
 			return -1;
 		} else {
 			return 0;
 		}
 	}

 	fwrite(buffer, info->page_size + info->oob_size, 1, dst);

 	for (i = 0; i < info->usable_page_size; i++) {
 		if (buffer[i] !=  0xff)
 			break;
 	}

 	/* We leave empty pages at 0xff. */
 	if (i == info->usable_page_size)
 		return 0;

 	/* Restore the source pointer to read it again. */
 	fseek(src, -cnt, SEEK_CUR);

 	/* Randomize unused space if scrambling is required. */
 	if (info->scramble) {
 		int offs;

 		if (info->boot0) {
 			size_t ret;

 			offs = steps * (info->ecc_step_size + eccbytes + 4);
 			cnt = info->page_size + info->oob_size - offs;
 			ret = fread(buffer + offs, 1, cnt, rnd);
 			if (!ret && !feof(rnd)) {
 				fprintf(stderr,
 					"Failed to read random data\n");
 				return -1;
 			}
 		} else {
 			offs = info->page_size + (steps * (eccbytes + 4));
 			cnt = info->page_size + info->oob_size - offs;
 			memset(buffer + offs, 0xff, cnt);
 			scramble(info, page, buffer + offs, cnt);
 		}
 		fseek(dst, pos + offs, SEEK_SET);
 		fwrite(buffer + offs, cnt, 1, dst);
 	}

 	for (i = 0; i < steps; i++) {
 		int ecc_offs, data_offs;
 		uint8_t *ecc;

 		memset(buffer, 0xff, info->ecc_step_size + eccbytes + 4);
 		ecc = buffer + info->ecc_step_size + 4;
 		if (info->boot0) {
 			data_offs = i * (info->ecc_step_size + eccbytes + 4);
 			ecc_offs = data_offs + info->ecc_step_size + 4;
 		} else {
 			data_offs = i * info->ecc_step_size;
 			ecc_offs = info->page_size + 4 + (i * (eccbytes + 4));
 		}

 		cnt = fread(buffer, 1, info->ecc_step_size, src);
 		if (!cnt && !feof(src)) {
 			fprintf(stderr,
 				"Failed to read data from the source\n");
 			return -1;
 		}

 		pad = info->ecc_step_size - cnt;
 		if (pad) {
 			if (info->scramble && info->boot0) {
 				size_t ret;

 				ret = fread(buffer + cnt, 1, pad, rnd);
 				if (!ret && !feof(rnd)) {
 					fprintf(stderr,
 						"Failed to read random data\n");
 					return -1;
 				}
 			} else {
 				memset(buffer + cnt, 0xff, pad);
 			}
 		}

 		memset(ecc, 0, eccbytes);
 		swap_bits(buffer, info->ecc_step_size + 4);
 		encode_bch(bch, buffer, info->ecc_step_size + 4, ecc);
 		swap_bits(buffer, info->ecc_step_size + 4);
 		swap_bits(ecc, eccbytes);
 		scramble(info, page, buffer, info->ecc_step_size + 4 + eccbytes);

 		fseek(dst, pos + data_offs, SEEK_SET);
 		fwrite(buffer, info->ecc_step_size, 1, dst);
 		fseek(dst, pos + ecc_offs - 4, SEEK_SET);
 		fwrite(ecc - 4, eccbytes + 4, 1, dst);
 	}

 	/* Fix BBM. */
 	fseek(dst, pos + info->page_size, SEEK_SET);
 	memset(buffer, 0xff, 2);
 	fwrite(buffer, 2, 1, dst);

 	/* Make dst pointer point to the next page. */
 	fseek(dst, pos + info->page_size + info->oob_size, SEEK_SET);

 	return 0;
 }

 static int create_image(const struct image_info *info)
 {
 	off_t page = info->offset / info->page_size;
 	struct bch_control *bch;
 	FILE *src, *dst, *rnd;
 	uint8_t *buffer;

 	bch = init_bch(14, info->ecc_strength, BCH_PRIMITIVE_POLY);
 	if (!bch) {
 		fprintf(stderr, "Failed to init the BCH engine\n");
 		return -1;
 	}

 	buffer = malloc(info->page_size + info->oob_size);
 	if (!buffer) {
 		fprintf(stderr, "Failed to allocate the NAND page buffer\n");
 		return -1;
 	}

 	memset(buffer, 0xff, info->page_size + info->oob_size);

 	src = fopen(info->source, "r");
 	if (!src) {
 		fprintf(stderr, "Failed to open source file (%s)\n",
 			info->source);
 		return -1;
 	}

 	dst = fopen(info->dest, "w");
 	if (!dst) {
 		fprintf(stderr, "Failed to open dest file (%s)\n", info->dest);
 		return -1;
 	}

 	rnd = fopen("/dev/urandom", "r");
 	if (!rnd) {
 		fprintf(stderr, "Failed to open /dev/urandom\n");
 		return -1;
 	}

 	while (!feof(src)) {
 		int ret;

 		ret = write_page(info, buffer, src, rnd, dst, bch, page++);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 static void display_help(int status)
 {
 	fprintf(status == EXIT_SUCCESS ? stdout : stderr,
 		"sunxi-nand-image-builder %s\n"
 		"\n"
 		"Usage: sunxi-nand-image-builder [OPTIONS] source-image output-image\n"
 		"\n"
 		"Creates a raw NAND image that can be read by the sunxi NAND controller.\n"
 		"\n"
 		"-h               --help               Display this help and exit\n"
 		"-c <str>/<step>  --ecc=<str>/<step>   ECC config (strength/step-size)\n"
 		"-p <size>        --page=<size>        Page size\n"
 		"-o <size>        --oob=<size>         OOB size\n"
 		"-u <size>        --usable=<size>      Usable page size\n"
 		"-e <size>        --eraseblock=<size>  Erase block size\n"
 		"-b               --boot0              Build a boot0 image.\n"
 		"-s               --scramble           Scramble data\n"
 		"-a <offset>      --address=<offset>   Where the image will be programmed.\n"
 		"\n"
 		"Notes:\n"
 		"All the information you need to pass to this tool should be part of\n"
 		"the NAND datasheet.\n"
 		"\n"
 		"The NAND controller only supports the following ECC configs\n"
 		"  Valid ECC strengths: 16, 24, 28, 32, 40, 48, 56, 60 and 64\n"
 		"  Valid ECC step size: 512 and 1024\n"
 		"\n"
 		"If you are building a boot0 image, you'll have specify extra options.\n"
 		"These options should be chosen based on the layouts described here:\n"
 		"  http://linux-sunxi.org/NAND#More_information_on_BROM_NAND\n"
 		"\n"
 		"  --usable should be assigned the 'Hardware page' value\n"
 		"  --ecc should be assigned the 'ECC capacity'/'ECC page' values\n"
 		"  --usable should be smaller than --page\n"
 		"\n"
 		"The --address option is only required for non-boot0 images that are \n"
 		"meant to be programmed at a non eraseblock aligned offset.\n"
 		"\n"
 		"Examples:\n"
 		"  The H27UCG8T2BTR-BC NAND exposes\n"
 		"  * 16k pages\n"
 		"  * 1280 OOB bytes per page\n"
 		"  * 4M eraseblocks\n"
 		"  * requires data scrambling\n"
 		"  * expects a minimum ECC of 40bits/1024bytes\n"
 		"\n"
 		"  A normal image can be generated with\n"
 		"    sunxi-nand-image-builder -p 16384 -o 1280 -e 0x400000 -s -c 40/1024\n"
 		"  A boot0 image can be generated with\n"
 		"    sunxi-nand-image-builder -p 16384 -o 1280 -e 0x400000 -s -b -u 4096 -c 64/1024\n",
 		PLAIN_VERSION);
 	exit(status);
 }

 static int check_image_info(struct image_info *info)
 {
 	static int valid_ecc_strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
 	int eccbytes, eccsteps;
 	unsigned i;

 	if (!info->page_size) {
 		fprintf(stderr, "--page is missing\n");
 		return -EINVAL;
 	}

 	if (!info->page_size) {
 		fprintf(stderr, "--oob is missing\n");
 		return -EINVAL;
 	}

 	if (!info->eraseblock_size) {
 		fprintf(stderr, "--eraseblock is missing\n");
 		return -EINVAL;
 	}

 	if (info->ecc_step_size != 512 && info->ecc_step_size != 1024) {
 		fprintf(stderr, "Invalid ECC step argument: %d\n",
 			info->ecc_step_size);
 		return -EINVAL;
 	}

 	for (i = 0; i < ARRAY_SIZE(valid_ecc_strengths); i++) {
 		if (valid_ecc_strengths[i] == info->ecc_strength)
 			break;
 	}

 	if (i == ARRAY_SIZE(valid_ecc_strengths)) {
 		fprintf(stderr, "Invalid ECC strength argument: %d\n",
 			info->ecc_strength);
 		return -EINVAL;
 	}

 	eccbytes = DIV_ROUND_UP(info->ecc_strength * 14, 8);
 	if (eccbytes % 2)
 		eccbytes++;
 	eccbytes += 4;

 	eccsteps = info->usable_page_size / info->ecc_step_size;

 	if (info->page_size + info->oob_size <
 	    info->usable_page_size + (eccsteps * eccbytes)) {
 		fprintf(stderr,
 			"ECC bytes do not fit in the NAND page, choose a weaker ECC\n");
 		return -EINVAL;
 	}

 	return 0;
 }

 int main(int argc, char **argv)
 {
 	struct image_info info;

 	memset(&info, 0, sizeof(info));
 	/*
 	 * Process user arguments
 	 */
 	for (;;) {
 		int option_index = 0;
 		char *endptr = NULL;
 		static const struct option long_options[] = {
 			{"help", no_argument, 0, 'h'},
 			{"ecc", required_argument, 0, 'c'},
 			{"page", required_argument, 0, 'p'},
 			{"oob", required_argument, 0, 'o'},
 			{"usable", required_argument, 0, 'u'},
 			{"eraseblock", required_argument, 0, 'e'},
 			{"boot0", no_argument, 0, 'b'},
 			{"scramble", no_argument, 0, 's'},
 			{"address", required_argument, 0, 'a'},
 			{0, 0, 0, 0},
 		};

 		int c = getopt_long(argc, argv, "c:p:o:u:e:ba:sh",
 				long_options, &option_index);
 		if (c == EOF)
 			break;

 		switch (c) {
 		case 'h':
 			display_help(0);
 			break;
 		case 's':
 			info.scramble = 1;
 			break;
 		case 'c':
 			info.ecc_strength = strtol(optarg, &endptr, 0);
 			if (*endptr == '/')
 				info.ecc_step_size = strtol(endptr + 1, NULL, 0);
 			break;
 		case 'p':
 			info.page_size = strtol(optarg, NULL, 0);
 			break;
 		case 'o':
 			info.oob_size = strtol(optarg, NULL, 0);
 			break;
 		case 'u':
 			info.usable_page_size = strtol(optarg, NULL, 0);
 			break;
 		case 'e':
 			info.eraseblock_size = strtol(optarg, NULL, 0);
 			break;
 		case 'b':
 			info.boot0 = 1;
 			break;
 		case 'a':
 			info.offset = strtoull(optarg, NULL, 0);
 			break;
 		case '?':
 			display_help(-1);
 			break;
 		}
 	}

 	if ((argc - optind) != 2)
 		display_help(-1);

 	info.source = argv[optind];
 	info.dest = argv[optind + 1];

 	if (!info.boot0) {
 		info.usable_page_size = info.page_size;
 	} else if (!info.usable_page_size) {
 		if (info.page_size > 8192)
 			info.usable_page_size = 8192;
 		else if (info.page_size > 4096)
 			info.usable_page_size = 4096;
 		else
 			info.usable_page_size = 1024;
 	}

 	if (check_image_info(&info))
 		display_help(-1);

 	return create_image(&info);
 }
	/*
	* Allwinner NAND randomizer and image builder implementation:
	*
	* Copyright © 2016 NextThing Co.
	* Copyright © 2016 Free Electrons
	*
	* Author: Boris Brezillon <boris.brezillon@free-electrons.com>
	*
	*/

	#include <linux/bch.h>

	#include <getopt.h>
	#include <version.h>

	#define BCH_PRIMITIVE_POLY 0x5803

	#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
	#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))

	struct image_info {
	int ecc_strength;
	int ecc_step_size;
	int page_size;
	int oob_size;
	int usable_page_size;
	int eraseblock_size;
	int scramble;
	int boot0;
	off_t offset;
	const char *source;
	const char *dest;
	};

	static void swap_bits(uint8_t *buf, int len)
	{
	int i, j;

	for (j = 0; j < len; j++) {
	uint8_t byte = buf[j];

	buf[j] = 0;
	for (i = 0; i < 8; i++) {
	if (byte & (1 << i))
	buf[j] \|= (1 << (7 - i));
	}
	}
	}

	static uint16_t lfsr_step(uint16_t state, int count)
	{
	state &= 0x7fff;
	while (count--)
	state = ((state >> 1) \|
	((((state >> 0) ^ (state >> 1)) & 1) << 14)) & 0x7fff;

	return state;
	}

	static uint16_t default_scrambler_seeds[] = {
	0x2b75, 0x0bd0, 0x5ca3, 0x62d1, 0x1c93, 0x07e9, 0x2162, 0x3a72,
	0x0d67, 0x67f9, 0x1be7, 0x077d, 0x032f, 0x0dac, 0x2716, 0x2436,
	0x7922, 0x1510, 0x3860, 0x5287, 0x480f, 0x4252, 0x1789, 0x5a2d,
	0x2a49, 0x5e10, 0x437f, 0x4b4e, 0x2f45, 0x216e, 0x5cb7, 0x7130,
	0x2a3f, 0x60e4, 0x4dc9, 0x0ef0, 0x0f52, 0x1bb9, 0x6211, 0x7a56,
	0x226d, 0x4ea7, 0x6f36, 0x3692, 0x38bf, 0x0c62, 0x05eb, 0x4c55,
	0x60f4, 0x728c, 0x3b6f, 0x2037, 0x7f69, 0x0936, 0x651a, 0x4ceb,
	0x6218, 0x79f3, 0x383f, 0x18d9, 0x4f05, 0x5c82, 0x2912, 0x6f17,
	0x6856, 0x5938, 0x1007, 0x61ab, 0x3e7f, 0x57c2, 0x542f, 0x4f62,
	0x7454, 0x2eac, 0x7739, 0x42d4, 0x2f90, 0x435a, 0x2e52, 0x2064,
	0x637c, 0x66ad, 0x2c90, 0x0bad, 0x759c, 0x0029, 0x0986, 0x7126,
	0x1ca7, 0x1605, 0x386a, 0x27f5, 0x1380, 0x6d75, 0x24c3, 0x0f8e,
	0x2b7a, 0x1418, 0x1fd1, 0x7dc1, 0x2d8e, 0x43af, 0x2267, 0x7da3,
	0x4e3d, 0x1338, 0x50db, 0x454d, 0x764d, 0x40a3, 0x42e6, 0x262b,
	0x2d2e, 0x1aea, 0x2e17, 0x173d, 0x3a6e, 0x71bf, 0x25f9, 0x0a5d,
	0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
	};

	static uint16_t brom_scrambler_seeds[] = { 0x4a80 };

	static void scramble(const struct image_info *info,
	int page, uint8_t *data, int datalen)
	{
	uint16_t state;
	int i;

	/* Boot0 is always scrambled no matter the command line option. */
	if (info->boot0) {
	state = brom_scrambler_seeds[0];
	} else {
	unsigned seedmod = info->eraseblock_size / info->page_size;

	/* Bail out earlier if the user didn't ask for scrambling. */
	if (!info->scramble)
	return;

	if (seedmod > ARRAY_SIZE(default_scrambler_seeds))
	seedmod = ARRAY_SIZE(default_scrambler_seeds);

	state = default_scrambler_seeds[page % seedmod];
	}

	/* Prepare the initial state... */
	state = lfsr_step(state, 15);

	/* and start scrambling data. */
	for (i = 0; i < datalen; i++) {
	data[i] ^= state;
	state = lfsr_step(state, 8);
	}
	}

	static int write_page(const struct image_info info, uint8_t buffer,
	FILE src, FILE rnd, FILE *dst,
	struct bch_control *bch, int page)
	{
	int steps = info->usable_page_size / info->ecc_step_size;
	int eccbytes = DIV_ROUND_UP(info->ecc_strength * 14, 8);
	off_t pos = ftell(dst);
	size_t pad, cnt;
	int i;

	if (eccbytes % 2)
	eccbytes++;

	memset(buffer, 0xff, info->page_size + info->oob_size);
	cnt = fread(buffer, 1, info->usable_page_size, src);
	if (!cnt) {
	if (!feof(src)) {
	fprintf(stderr,
	"Failed to read data from the source\n");
	return -1;
	} else {
	return 0;
	}
	}

	fwrite(buffer, info->page_size + info->oob_size, 1, dst);

	for (i = 0; i < info->usable_page_size; i++) {
	if (buffer[i] != 0xff)
	break;
	}

	/* We leave empty pages at 0xff. */
	if (i == info->usable_page_size)
	return 0;

	/* Restore the source pointer to read it again. */
	fseek(src, -cnt, SEEK_CUR);

	/* Randomize unused space if scrambling is required. */
	if (info->scramble) {
	int offs;

	if (info->boot0) {
	size_t ret;

	offs = steps * (info->ecc_step_size + eccbytes + 4);
	cnt = info->page_size + info->oob_size - offs;
	ret = fread(buffer + offs, 1, cnt, rnd);
	if (!ret && !feof(rnd)) {
	fprintf(stderr,
	"Failed to read random data\n");
	return -1;
	}
	} else {
	offs = info->page_size + (steps * (eccbytes + 4));
	cnt = info->page_size + info->oob_size - offs;
	memset(buffer + offs, 0xff, cnt);
	scramble(info, page, buffer + offs, cnt);
	}
	fseek(dst, pos + offs, SEEK_SET);
	fwrite(buffer + offs, cnt, 1, dst);
	}

	for (i = 0; i < steps; i++) {
	int ecc_offs, data_offs;
	uint8_t *ecc;

	memset(buffer, 0xff, info->ecc_step_size + eccbytes + 4);
	ecc = buffer + info->ecc_step_size + 4;
	if (info->boot0) {
	data_offs = i * (info->ecc_step_size + eccbytes + 4);
	ecc_offs = data_offs + info->ecc_step_size + 4;
	} else {
	data_offs = i * info->ecc_step_size;
	ecc_offs = info->page_size + 4 + (i * (eccbytes + 4));
	}

	cnt = fread(buffer, 1, info->ecc_step_size, src);
	if (!cnt && !feof(src)) {
	fprintf(stderr,
	"Failed to read data from the source\n");
	return -1;
	}

	pad = info->ecc_step_size - cnt;
	if (pad) {
	if (info->scramble && info->boot0) {
	size_t ret;

	ret = fread(buffer + cnt, 1, pad, rnd);
	if (!ret && !feof(rnd)) {
	fprintf(stderr,
	"Failed to read random data\n");
	return -1;
	}
	} else {
	memset(buffer + cnt, 0xff, pad);
	}
	}

	memset(ecc, 0, eccbytes);
	swap_bits(buffer, info->ecc_step_size + 4);
	encode_bch(bch, buffer, info->ecc_step_size + 4, ecc);
	swap_bits(buffer, info->ecc_step_size + 4);
	swap_bits(ecc, eccbytes);
	scramble(info, page, buffer, info->ecc_step_size + 4 + eccbytes);

	fseek(dst, pos + data_offs, SEEK_SET);
	fwrite(buffer, info->ecc_step_size, 1, dst);
	fseek(dst, pos + ecc_offs - 4, SEEK_SET);
	fwrite(ecc - 4, eccbytes + 4, 1, dst);
	}

	/* Fix BBM. */
	fseek(dst, pos + info->page_size, SEEK_SET);
	memset(buffer, 0xff, 2);
	fwrite(buffer, 2, 1, dst);

	/* Make dst pointer point to the next page. */
	fseek(dst, pos + info->page_size + info->oob_size, SEEK_SET);

	return 0;
	}

	static int create_image(const struct image_info *info)
	{
	off_t page = info->offset / info->page_size;
	struct bch_control *bch;
	FILE src, dst, *rnd;
	uint8_t *buffer;

	bch = init_bch(14, info->ecc_strength, BCH_PRIMITIVE_POLY);
	if (!bch) {
	fprintf(stderr, "Failed to init the BCH engine\n");
	return -1;
	}

	buffer = malloc(info->page_size + info->oob_size);
	if (!buffer) {
	fprintf(stderr, "Failed to allocate the NAND page buffer\n");
	return -1;
	}

	memset(buffer, 0xff, info->page_size + info->oob_size);

	src = fopen(info->source, "r");
	if (!src) {
	fprintf(stderr, "Failed to open source file (%s)\n",
	info->source);
	return -1;
	}

	dst = fopen(info->dest, "w");
	if (!dst) {
	fprintf(stderr, "Failed to open dest file (%s)\n", info->dest);
	return -1;
	}

	rnd = fopen("/dev/urandom", "r");
	if (!rnd) {
	fprintf(stderr, "Failed to open /dev/urandom\n");
	return -1;
	}

	while (!feof(src)) {
	int ret;

	ret = write_page(info, buffer, src, rnd, dst, bch, page++);
	if (ret)
	return ret;
	}

	return 0;
	}

	static void display_help(int status)
	{
	fprintf(status == EXIT_SUCCESS ? stdout : stderr,
	"sunxi-nand-image-builder %s\n"
	"\n"
	"Usage: sunxi-nand-image-builder [OPTIONS] source-image output-image\n"
	"\n"
	"Creates a raw NAND image that can be read by the sunxi NAND controller.\n"
	"\n"
	"-h --help Display this help and exit\n"
	"-c <str>/<step> --ecc=<str>/<step> ECC config (strength/step-size)\n"
	"-p <size> --page=<size> Page size\n"
	"-o <size> --oob=<size> OOB size\n"
	"-u <size> --usable=<size> Usable page size\n"
	"-e <size> --eraseblock=<size> Erase block size\n"
	"-b --boot0 Build a boot0 image.\n"
	"-s --scramble Scramble data\n"
	"-a <offset> --address=<offset> Where the image will be programmed.\n"
	"\n"
	"Notes:\n"
	"All the information you need to pass to this tool should be part of\n"
	"the NAND datasheet.\n"
	"\n"
	"The NAND controller only supports the following ECC configs\n"
	" Valid ECC strengths: 16, 24, 28, 32, 40, 48, 56, 60 and 64\n"
	" Valid ECC step size: 512 and 1024\n"
	"\n"
	"If you are building a boot0 image, you'll have specify extra options.\n"
	"These options should be chosen based on the layouts described here:\n"
	" http://linux-sunxi.org/NAND#More_information_on_BROM_NAND\n"
	"\n"
	" --usable should be assigned the 'Hardware page' value\n"
	" --ecc should be assigned the 'ECC capacity'/'ECC page' values\n"
	" --usable should be smaller than --page\n"
	"\n"
	"The --address option is only required for non-boot0 images that are \n"
	"meant to be programmed at a non eraseblock aligned offset.\n"
	"\n"
	"Examples:\n"
	" The H27UCG8T2BTR-BC NAND exposes\n"
	" * 16k pages\n"
	" * 1280 OOB bytes per page\n"
	" * 4M eraseblocks\n"
	" * requires data scrambling\n"
	" * expects a minimum ECC of 40bits/1024bytes\n"
	"\n"
	" A normal image can be generated with\n"
	" sunxi-nand-image-builder -p 16384 -o 1280 -e 0x400000 -s -c 40/1024\n"
	" A boot0 image can be generated with\n"
	" sunxi-nand-image-builder -p 16384 -o 1280 -e 0x400000 -s -b -u 4096 -c 64/1024\n",
	PLAIN_VERSION);
	exit(status);
	}

	static int check_image_info(struct image_info *info)
	{
	static int valid_ecc_strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
	int eccbytes, eccsteps;
	unsigned i;

	if (!info->page_size) {
	fprintf(stderr, "--page is missing\n");
	return -EINVAL;
	}

	if (!info->page_size) {
	fprintf(stderr, "--oob is missing\n");
	return -EINVAL;
	}

	if (!info->eraseblock_size) {
	fprintf(stderr, "--eraseblock is missing\n");
	return -EINVAL;
	}

	if (info->ecc_step_size != 512 && info->ecc_step_size != 1024) {
	fprintf(stderr, "Invalid ECC step argument: %d\n",
	info->ecc_step_size);
	return -EINVAL;
	}

	for (i = 0; i < ARRAY_SIZE(valid_ecc_strengths); i++) {
	if (valid_ecc_strengths[i] == info->ecc_strength)
	break;
	}

	if (i == ARRAY_SIZE(valid_ecc_strengths)) {
	fprintf(stderr, "Invalid ECC strength argument: %d\n",
	info->ecc_strength);
	return -EINVAL;
	}

	eccbytes = DIV_ROUND_UP(info->ecc_strength * 14, 8);
	if (eccbytes % 2)
	eccbytes++;
	eccbytes += 4;

	eccsteps = info->usable_page_size / info->ecc_step_size;

	if (info->page_size + info->oob_size <
	info->usable_page_size + (eccsteps * eccbytes)) {
	fprintf(stderr,
	"ECC bytes do not fit in the NAND page, choose a weaker ECC\n");
	return -EINVAL;
	}

	return 0;
	}

	int main(int argc, char **argv)
	{
	struct image_info info;

	memset(&info, 0, sizeof(info));
	/*
	* Process user arguments
	*/
	for (;;) {
	int option_index = 0;
	char *endptr = NULL;
	static const struct option long_options[] = {
	{"help", no_argument, 0, 'h'},
	{"ecc", required_argument, 0, 'c'},
	{"page", required_argument, 0, 'p'},
	{"oob", required_argument, 0, 'o'},
	{"usable", required_argument, 0, 'u'},
	{"eraseblock", required_argument, 0, 'e'},
	{"boot0", no_argument, 0, 'b'},
	{"scramble", no_argument, 0, 's'},
	{"address", required_argument, 0, 'a'},
	{0, 0, 0, 0},
	};

	int c = getopt_long(argc, argv, "c:p:o:u:e:ba:sh",
	long_options, &option_index);
	if (c == EOF)
	break;

	switch (c) {
	case 'h':
	display_help(0);
	break;
	case 's':
	info.scramble = 1;
	break;
	case 'c':
	info.ecc_strength = strtol(optarg, &endptr, 0);
	if (*endptr == '/')
	info.ecc_step_size = strtol(endptr + 1, NULL, 0);
	break;
	case 'p':
	info.page_size = strtol(optarg, NULL, 0);
	break;
	case 'o':
	info.oob_size = strtol(optarg, NULL, 0);
	break;
	case 'u':
	info.usable_page_size = strtol(optarg, NULL, 0);
	break;
	case 'e':
	info.eraseblock_size = strtol(optarg, NULL, 0);
	break;
	case 'b':
	info.boot0 = 1;
	break;
	case 'a':
	info.offset = strtoull(optarg, NULL, 0);
	break;
	case '?':
	display_help(-1);
	break;
	}
	}

	if ((argc - optind) != 2)
	display_help(-1);

	info.source = argv[optind];
	info.dest = argv[optind + 1];

	if (!info.boot0) {
	info.usable_page_size = info.page_size;
	} else if (!info.usable_page_size) {
	if (info.page_size > 8192)
	info.usable_page_size = 8192;
	else if (info.page_size > 4096)
	info.usable_page_size = 4096;
	else
	info.usable_page_size = 1024;
	}

	if (check_image_info(&info))
	display_help(-1);

	return create_image(&info);
	}