diff --git a/tools/.gitignore b/tools/.gitignore
index cb1e722d4575..16574467544c 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -15,6 +15,7 @@
 /mkexynosspl
 /mxsboot
 /mksunxiboot
+/sunxi-spl-image-builder
 /ncb
 /proftool
 /relocate-rela
diff --git a/tools/Makefile b/tools/Makefile
index 400588cf0f5c..dfeeb23484ce 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -171,6 +171,7 @@ hostprogs-$(CONFIG_MX28) += mxsboot
 HOSTCFLAGS_mxsboot.o := -pedantic
 
 hostprogs-$(CONFIG_ARCH_SUNXI) += mksunxiboot
+hostprogs-$(CONFIG_ARCH_SUNXI) += sunxi-spl-image-builder
 
 hostprogs-$(CONFIG_NETCONSOLE) += ncb
 hostprogs-$(CONFIG_SHA1_CHECK_UB_IMG) += ubsha1
diff --git a/tools/sunxi-spl-image-builder.c b/tools/sunxi-spl-image-builder.c
new file mode 100644
index 000000000000..0f915eb2bdf5
--- /dev/null
+++ b/tools/sunxi-spl-image-builder.c
@@ -0,0 +1,1113 @@
+/*
+ * Generic binary BCH encoding/decoding library
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * 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.
+ *
+ * For the BCH implementation:
+ *
+ * Copyright © 2011 Parrot S.A.
+ *
+ * Author: Ivan Djelic <ivan.djelic@parrot.com>
+ *
+ * See also:
+ * http://lxr.free-electrons.com/source/lib/bch.c
+ *
+ * For the randomizer and image builder implementation:
+ *
+ * Copyright © 2016 NextThing Co.
+ * Copyright © 2016 Free Electrons
+ *
+ * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
+ *
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <asm/byteorder.h>
+#include <endian.h>
+#include <getopt.h>
+#include <version.h>
+
+#if defined(CONFIG_BCH_CONST_PARAMS)
+#define GF_M(_p)               (CONFIG_BCH_CONST_M)
+#define GF_T(_p)               (CONFIG_BCH_CONST_T)
+#define GF_N(_p)               ((1 << (CONFIG_BCH_CONST_M))-1)
+#else
+#define GF_M(_p)               ((_p)->m)
+#define GF_T(_p)               ((_p)->t)
+#define GF_N(_p)               ((_p)->n)
+#endif
+
+#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
+
+#define BCH_ECC_WORDS(_p)      DIV_ROUND_UP(GF_M(_p)*GF_T(_p), 32)
+#define BCH_ECC_BYTES(_p)      DIV_ROUND_UP(GF_M(_p)*GF_T(_p), 8)
+
+#ifndef dbg
+#define dbg(_fmt, args...)     do {} while (0)
+#endif
+
+#define cpu_to_be32 htobe32
+#define kfree free
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+#define BCH_PRIMITIVE_POLY	0x5803
+
+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;
+};
+
+/**
+ * struct bch_control - BCH control structure
+ * @m:          Galois field order
+ * @n:          maximum codeword size in bits (= 2^m-1)
+ * @t:          error correction capability in bits
+ * @ecc_bits:   ecc exact size in bits, i.e. generator polynomial degree (<=m*t)
+ * @ecc_bytes:  ecc max size (m*t bits) in bytes
+ * @a_pow_tab:  Galois field GF(2^m) exponentiation lookup table
+ * @a_log_tab:  Galois field GF(2^m) log lookup table
+ * @mod8_tab:   remainder generator polynomial lookup tables
+ * @ecc_buf:    ecc parity words buffer
+ * @ecc_buf2:   ecc parity words buffer
+ * @xi_tab:     GF(2^m) base for solving degree 2 polynomial roots
+ * @syn:        syndrome buffer
+ * @cache:      log-based polynomial representation buffer
+ * @elp:        error locator polynomial
+ * @poly_2t:    temporary polynomials of degree 2t
+ */
+struct bch_control {
+	unsigned int    m;
+	unsigned int    n;
+	unsigned int    t;
+	unsigned int    ecc_bits;
+	unsigned int    ecc_bytes;
+/* private: */
+	uint16_t       *a_pow_tab;
+	uint16_t       *a_log_tab;
+	uint32_t       *mod8_tab;
+	uint32_t       *ecc_buf;
+	uint32_t       *ecc_buf2;
+	unsigned int   *xi_tab;
+	unsigned int   *syn;
+	int            *cache;
+	struct gf_poly *elp;
+	struct gf_poly *poly_2t[4];
+};
+
+static int fls(int x)
+{
+	int r = 32;
+
+	if (!x)
+		return 0;
+	if (!(x & 0xffff0000u)) {
+		x <<= 16;
+		r -= 16;
+	}
+	if (!(x & 0xff000000u)) {
+		x <<= 8;
+		r -= 8;
+	}
+	if (!(x & 0xf0000000u)) {
+		x <<= 4;
+		r -= 4;
+	}
+	if (!(x & 0xc0000000u)) {
+		x <<= 2;
+		r -= 2;
+	}
+	if (!(x & 0x80000000u)) {
+		x <<= 1;
+		r -= 1;
+	}
+	return r;
+}
+
+/*
+ * represent a polynomial over GF(2^m)
+ */
+struct gf_poly {
+	unsigned int deg;    /* polynomial degree */
+	unsigned int c[0];   /* polynomial terms */
+};
+
+/* given its degree, compute a polynomial size in bytes */
+#define GF_POLY_SZ(_d) (sizeof(struct gf_poly)+((_d)+1)*sizeof(unsigned int))
+
+/* polynomial of degree 1 */
+struct gf_poly_deg1 {
+	struct gf_poly poly;
+	unsigned int   c[2];
+};
+
+/*
+ * same as encode_bch(), but process input data one byte at a time
+ */
+static void encode_bch_unaligned(struct bch_control *bch,
+				 const unsigned char *data, unsigned int len,
+				 uint32_t *ecc)
+{
+	int i;
+	const uint32_t *p;
+	const int l = BCH_ECC_WORDS(bch)-1;
+
+	while (len--) {
+		p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(*data++)) & 0xff);
+
+		for (i = 0; i < l; i++)
+			ecc[i] = ((ecc[i] << 8)|(ecc[i+1] >> 24))^(*p++);
+
+		ecc[l] = (ecc[l] << 8)^(*p);
+	}
+}
+
+/*
+ * convert ecc bytes to aligned, zero-padded 32-bit ecc words
+ */
+static void load_ecc8(struct bch_control *bch, uint32_t *dst,
+		      const uint8_t *src)
+{
+	uint8_t pad[4] = {0, 0, 0, 0};
+	unsigned int i, nwords = BCH_ECC_WORDS(bch)-1;
+
+	for (i = 0; i < nwords; i++, src += 4)
+		dst[i] = (src[0] << 24)|(src[1] << 16)|(src[2] << 8)|src[3];
+
+	memcpy(pad, src, BCH_ECC_BYTES(bch)-4*nwords);
+	dst[nwords] = (pad[0] << 24)|(pad[1] << 16)|(pad[2] << 8)|pad[3];
+}
+
+/*
+ * convert 32-bit ecc words to ecc bytes
+ */
+static void store_ecc8(struct bch_control *bch, uint8_t *dst,
+		       const uint32_t *src)
+{
+	uint8_t pad[4];
+	unsigned int i, nwords = BCH_ECC_WORDS(bch)-1;
+
+	for (i = 0; i < nwords; i++) {
+		*dst++ = (src[i] >> 24);
+		*dst++ = (src[i] >> 16) & 0xff;
+		*dst++ = (src[i] >>  8) & 0xff;
+		*dst++ = (src[i] >>  0) & 0xff;
+	}
+	pad[0] = (src[nwords] >> 24);
+	pad[1] = (src[nwords] >> 16) & 0xff;
+	pad[2] = (src[nwords] >>  8) & 0xff;
+	pad[3] = (src[nwords] >>  0) & 0xff;
+	memcpy(dst, pad, BCH_ECC_BYTES(bch)-4*nwords);
+}
+
+/**
+ * encode_bch - calculate BCH ecc parity of data
+ * @bch:   BCH control structure
+ * @data:  data to encode
+ * @len:   data length in bytes
+ * @ecc:   ecc parity data, must be initialized by caller
+ *
+ * The @ecc parity array is used both as input and output parameter, in order to
+ * allow incremental computations. It should be of the size indicated by member
+ * @ecc_bytes of @bch, and should be initialized to 0 before the first call.
+ *
+ * The exact number of computed ecc parity bits is given by member @ecc_bits of
+ * @bch; it may be less than m*t for large values of t.
+ */
+static void encode_bch(struct bch_control *bch, const uint8_t *data,
+		unsigned int len, uint8_t *ecc)
+{
+	const unsigned int l = BCH_ECC_WORDS(bch)-1;
+	unsigned int i, mlen;
+	unsigned long m;
+	uint32_t w, r[l+1];
+	const uint32_t * const tab0 = bch->mod8_tab;
+	const uint32_t * const tab1 = tab0 + 256*(l+1);
+	const uint32_t * const tab2 = tab1 + 256*(l+1);
+	const uint32_t * const tab3 = tab2 + 256*(l+1);
+	const uint32_t *pdata, *p0, *p1, *p2, *p3;
+
+	if (ecc) {
+		/* load ecc parity bytes into internal 32-bit buffer */
+		load_ecc8(bch, bch->ecc_buf, ecc);
+	} else {
+		memset(bch->ecc_buf, 0, sizeof(r));
+	}
+
+	/* process first unaligned data bytes */
+	m = ((uintptr_t)data) & 3;
+	if (m) {
+		mlen = (len < (4-m)) ? len : 4-m;
+		encode_bch_unaligned(bch, data, mlen, bch->ecc_buf);
+		data += mlen;
+		len  -= mlen;
+	}
+
+	/* process 32-bit aligned data words */
+	pdata = (uint32_t *)data;
+	mlen  = len/4;
+	data += 4*mlen;
+	len  -= 4*mlen;
+	memcpy(r, bch->ecc_buf, sizeof(r));
+
+	/*
+	 * split each 32-bit word into 4 polynomials of weight 8 as follows:
+	 *
+	 * 31 ...24  23 ...16  15 ... 8  7 ... 0
+	 * xxxxxxxx  yyyyyyyy  zzzzzzzz  tttttttt
+	 *                               tttttttt  mod g = r0 (precomputed)
+	 *                     zzzzzzzz  00000000  mod g = r1 (precomputed)
+	 *           yyyyyyyy  00000000  00000000  mod g = r2 (precomputed)
+	 * xxxxxxxx  00000000  00000000  00000000  mod g = r3 (precomputed)
+	 * xxxxxxxx  yyyyyyyy  zzzzzzzz  tttttttt  mod g = r0^r1^r2^r3
+	 */
+	while (mlen--) {
+		/* input data is read in big-endian format */
+		w = r[0]^cpu_to_be32(*pdata++);
+		p0 = tab0 + (l+1)*((w >>  0) & 0xff);
+		p1 = tab1 + (l+1)*((w >>  8) & 0xff);
+		p2 = tab2 + (l+1)*((w >> 16) & 0xff);
+		p3 = tab3 + (l+1)*((w >> 24) & 0xff);
+
+		for (i = 0; i < l; i++)
+			r[i] = r[i+1]^p0[i]^p1[i]^p2[i]^p3[i];
+
+		r[l] = p0[l]^p1[l]^p2[l]^p3[l];
+	}
+	memcpy(bch->ecc_buf, r, sizeof(r));
+
+	/* process last unaligned bytes */
+	if (len)
+		encode_bch_unaligned(bch, data, len, bch->ecc_buf);
+
+	/* store ecc parity bytes into original parity buffer */
+	if (ecc)
+		store_ecc8(bch, ecc, bch->ecc_buf);
+}
+
+static inline int modulo(struct bch_control *bch, unsigned int v)
+{
+	const unsigned int n = GF_N(bch);
+	while (v >= n) {
+		v -= n;
+		v = (v & n) + (v >> GF_M(bch));
+	}
+	return v;
+}
+
+/*
+ * shorter and faster modulo function, only works when v < 2N.
+ */
+static inline int mod_s(struct bch_control *bch, unsigned int v)
+{
+	const unsigned int n = GF_N(bch);
+	return (v < n) ? v : v-n;
+}
+
+static inline int deg(unsigned int poly)
+{
+	/* polynomial degree is the most-significant bit index */
+	return fls(poly)-1;
+}
+
+/* Galois field basic operations: multiply, divide, inverse, etc. */
+
+static inline unsigned int gf_mul(struct bch_control *bch, unsigned int a,
+				  unsigned int b)
+{
+	return (a && b) ? bch->a_pow_tab[mod_s(bch, bch->a_log_tab[a]+
+					       bch->a_log_tab[b])] : 0;
+}
+
+static inline unsigned int gf_sqr(struct bch_control *bch, unsigned int a)
+{
+	return a ? bch->a_pow_tab[mod_s(bch, 2*bch->a_log_tab[a])] : 0;
+}
+
+static inline unsigned int a_pow(struct bch_control *bch, int i)
+{
+	return bch->a_pow_tab[modulo(bch, i)];
+}
+
+static inline int a_log(struct bch_control *bch, unsigned int x)
+{
+	return bch->a_log_tab[x];
+}
+
+/*
+ * generate Galois field lookup tables
+ */
+static int build_gf_tables(struct bch_control *bch, unsigned int poly)
+{
+	unsigned int i, x = 1;
+	const unsigned int k = 1 << deg(poly);
+
+	/* primitive polynomial must be of degree m */
+	if (k != (1u << GF_M(bch)))
+		return -1;
+
+	for (i = 0; i < GF_N(bch); i++) {
+		bch->a_pow_tab[i] = x;
+		bch->a_log_tab[x] = i;
+		if (i && (x == 1))
+			/* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */
+			return -1;
+		x <<= 1;
+		if (x & k)
+			x ^= poly;
+	}
+	bch->a_pow_tab[GF_N(bch)] = 1;
+	bch->a_log_tab[0] = 0;
+
+	return 0;
+}
+
+/*
+ * compute generator polynomial remainder tables for fast encoding
+ */
+static void build_mod8_tables(struct bch_control *bch, const uint32_t *g)
+{
+	int i, j, b, d;
+	uint32_t data, hi, lo, *tab;
+	const int l = BCH_ECC_WORDS(bch);
+	const int plen = DIV_ROUND_UP(bch->ecc_bits+1, 32);
+	const int ecclen = DIV_ROUND_UP(bch->ecc_bits, 32);
+
+	memset(bch->mod8_tab, 0, 4*256*l*sizeof(*bch->mod8_tab));
+
+	for (i = 0; i < 256; i++) {
+		/* p(X)=i is a small polynomial of weight <= 8 */
+		for (b = 0; b < 4; b++) {
+			/* we want to compute (p(X).X^(8*b+deg(g))) mod g(X) */
+			tab = bch->mod8_tab + (b*256+i)*l;
+			data = i << (8*b);
+			while (data) {
+				d = deg(data);
+				/* subtract X^d.g(X) from p(X).X^(8*b+deg(g)) */
+				data ^= g[0] >> (31-d);
+				for (j = 0; j < ecclen; j++) {
+					hi = (d < 31) ? g[j] << (d+1) : 0;
+					lo = (j+1 < plen) ?
+						g[j+1] >> (31-d) : 0;
+					tab[j] ^= hi|lo;
+				}
+			}
+		}
+	}
+}
+
+/*
+ * build a base for factoring degree 2 polynomials
+ */
+static int build_deg2_base(struct bch_control *bch)
+{
+	const int m = GF_M(bch);
+	int i, j, r;
+	unsigned int sum, x, y, remaining, ak = 0, xi[m];
+
+	/* find k s.t. Tr(a^k) = 1 and 0 <= k < m */
+	for (i = 0; i < m; i++) {
+		for (j = 0, sum = 0; j < m; j++)
+			sum ^= a_pow(bch, i*(1 << j));
+
+		if (sum) {
+			ak = bch->a_pow_tab[i];
+			break;
+		}
+	}
+	/* find xi, i=0..m-1 such that xi^2+xi = a^i+Tr(a^i).a^k */
+	remaining = m;
+	memset(xi, 0, sizeof(xi));
+
+	for (x = 0; (x <= GF_N(bch)) && remaining; x++) {
+		y = gf_sqr(bch, x)^x;
+		for (i = 0; i < 2; i++) {
+			r = a_log(bch, y);
+			if (y && (r < m) && !xi[r]) {
+				bch->xi_tab[r] = x;
+				xi[r] = 1;
+				remaining--;
+				dbg("x%d = %x\n", r, x);
+				break;
+			}
+			y ^= ak;
+		}
+	}
+	/* should not happen but check anyway */
+	return remaining ? -1 : 0;
+}
+
+static void *bch_alloc(size_t size, int *err)
+{
+	void *ptr;
+
+	ptr = malloc(size);
+	if (ptr == NULL)
+		*err = 1;
+	return ptr;
+}
+
+/*
+ * compute generator polynomial for given (m,t) parameters.
+ */
+static uint32_t *compute_generator_polynomial(struct bch_control *bch)
+{
+	const unsigned int m = GF_M(bch);
+	const unsigned int t = GF_T(bch);
+	int n, err = 0;
+	unsigned int i, j, nbits, r, word, *roots;
+	struct gf_poly *g;
+	uint32_t *genpoly;
+
+	g = bch_alloc(GF_POLY_SZ(m*t), &err);
+	roots = bch_alloc((bch->n+1)*sizeof(*roots), &err);
+	genpoly = bch_alloc(DIV_ROUND_UP(m*t+1, 32)*sizeof(*genpoly), &err);
+
+	if (err) {
+		kfree(genpoly);
+		genpoly = NULL;
+		goto finish;
+	}
+
+	/* enumerate all roots of g(X) */
+	memset(roots , 0, (bch->n+1)*sizeof(*roots));
+	for (i = 0; i < t; i++) {
+		for (j = 0, r = 2*i+1; j < m; j++) {
+			roots[r] = 1;
+			r = mod_s(bch, 2*r);
+		}
+	}
+	/* build generator polynomial g(X) */
+	g->deg = 0;
+	g->c[0] = 1;
+	for (i = 0; i < GF_N(bch); i++) {
+		if (roots[i]) {
+			/* multiply g(X) by (X+root) */
+			r = bch->a_pow_tab[i];
+			g->c[g->deg+1] = 1;
+			for (j = g->deg; j > 0; j--)
+				g->c[j] = gf_mul(bch, g->c[j], r)^g->c[j-1];
+
+			g->c[0] = gf_mul(bch, g->c[0], r);
+			g->deg++;
+		}
+	}
+	/* store left-justified binary representation of g(X) */
+	n = g->deg+1;
+	i = 0;
+
+	while (n > 0) {
+		nbits = (n > 32) ? 32 : n;
+		for (j = 0, word = 0; j < nbits; j++) {
+			if (g->c[n-1-j])
+				word |= 1u << (31-j);
+		}
+		genpoly[i++] = word;
+		n -= nbits;
+	}
+	bch->ecc_bits = g->deg;
+
+finish:
+	kfree(g);
+	kfree(roots);
+
+	return genpoly;
+}
+
+/**
+ *  free_bch - free the BCH control structure
+ *  @bch:    BCH control structure to release
+ */
+static void free_bch(struct bch_control *bch)
+{
+	unsigned int i;
+
+	if (bch) {
+		kfree(bch->a_pow_tab);
+		kfree(bch->a_log_tab);
+		kfree(bch->mod8_tab);
+		kfree(bch->ecc_buf);
+		kfree(bch->ecc_buf2);
+		kfree(bch->xi_tab);
+		kfree(bch->syn);
+		kfree(bch->cache);
+		kfree(bch->elp);
+
+		for (i = 0; i < ARRAY_SIZE(bch->poly_2t); i++)
+			kfree(bch->poly_2t[i]);
+
+		kfree(bch);
+	}
+}
+
+/**
+ * init_bch - initialize a BCH encoder/decoder
+ * @m:          Galois field order, should be in the range 5-15
+ * @t:          maximum error correction capability, in bits
+ * @prim_poly:  user-provided primitive polynomial (or 0 to use default)
+ *
+ * Returns:
+ *  a newly allocated BCH control structure if successful, NULL otherwise
+ *
+ * This initialization can take some time, as lookup tables are built for fast
+ * encoding/decoding; make sure not to call this function from a time critical
+ * path. Usually, init_bch() should be called on module/driver init and
+ * free_bch() should be called to release memory on exit.
+ *
+ * You may provide your own primitive polynomial of degree @m in argument
+ * @prim_poly, or let init_bch() use its default polynomial.
+ *
+ * Once init_bch() has successfully returned a pointer to a newly allocated
+ * BCH control structure, ecc length in bytes is given by member @ecc_bytes of
+ * the structure.
+ */
+static struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
+{
+	int err = 0;
+	unsigned int i, words;
+	uint32_t *genpoly;
+	struct bch_control *bch = NULL;
+
+	const int min_m = 5;
+	const int max_m = 15;
+
+	/* default primitive polynomials */
+	static const unsigned int prim_poly_tab[] = {
+		0x25, 0x43, 0x83, 0x11d, 0x211, 0x409, 0x805, 0x1053, 0x201b,
+		0x402b, 0x8003,
+	};
+
+#if defined(CONFIG_BCH_CONST_PARAMS)
+	if ((m != (CONFIG_BCH_CONST_M)) || (t != (CONFIG_BCH_CONST_T))) {
+		printk(KERN_ERR "bch encoder/decoder was configured to support "
+		       "parameters m=%d, t=%d only!\n",
+		       CONFIG_BCH_CONST_M, CONFIG_BCH_CONST_T);
+		goto fail;
+	}
+#endif
+	if ((m < min_m) || (m > max_m))
+		/*
+		 * values of m greater than 15 are not currently supported;
+		 * supporting m > 15 would require changing table base type
+		 * (uint16_t) and a small patch in matrix transposition
+		 */
+		goto fail;
+
+	/* sanity checks */
+	if ((t < 1) || (m*t >= ((1 << m)-1)))
+		/* invalid t value */
+		goto fail;
+
+	/* select a primitive polynomial for generating GF(2^m) */
+	if (prim_poly == 0)
+		prim_poly = prim_poly_tab[m-min_m];
+
+	bch = malloc(sizeof(*bch));
+	if (bch == NULL)
+		goto fail;
+
+	memset(bch, 0, sizeof(*bch));
+
+	bch->m = m;
+	bch->t = t;
+	bch->n = (1 << m)-1;
+	words  = DIV_ROUND_UP(m*t, 32);
+	bch->ecc_bytes = DIV_ROUND_UP(m*t, 8);
+	bch->a_pow_tab = bch_alloc((1+bch->n)*sizeof(*bch->a_pow_tab), &err);
+	bch->a_log_tab = bch_alloc((1+bch->n)*sizeof(*bch->a_log_tab), &err);
+	bch->mod8_tab  = bch_alloc(words*1024*sizeof(*bch->mod8_tab), &err);
+	bch->ecc_buf   = bch_alloc(words*sizeof(*bch->ecc_buf), &err);
+	bch->ecc_buf2  = bch_alloc(words*sizeof(*bch->ecc_buf2), &err);
+	bch->xi_tab    = bch_alloc(m*sizeof(*bch->xi_tab), &err);
+	bch->syn       = bch_alloc(2*t*sizeof(*bch->syn), &err);
+	bch->cache     = bch_alloc(2*t*sizeof(*bch->cache), &err);
+	bch->elp       = bch_alloc((t+1)*sizeof(struct gf_poly_deg1), &err);
+
+	for (i = 0; i < ARRAY_SIZE(bch->poly_2t); i++)
+		bch->poly_2t[i] = bch_alloc(GF_POLY_SZ(2*t), &err);
+
+	if (err)
+		goto fail;
+
+	err = build_gf_tables(bch, prim_poly);
+	if (err)
+		goto fail;
+
+	/* use generator polynomial for computing encoding tables */
+	genpoly = compute_generator_polynomial(bch);
+	if (genpoly == NULL)
+		goto fail;
+
+	build_mod8_tables(bch, genpoly);
+	kfree(genpoly);
+
+	err = build_deg2_base(bch);
+	if (err)
+		goto fail;
+
+	return bch;
+
+fail:
+	free_bch(bch);
+	return NULL;
+}
+
+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) {
+			offs = steps * (info->ecc_step_size + eccbytes + 4);
+			cnt = info->page_size + info->oob_size - offs;
+			fread(buffer + offs, 1, cnt, rnd);
+		} 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)
+				fread(buffer + cnt, 1, pad, rnd);
+			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 || *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);
+}
