diff --git a/Makefile b/Makefile deleted file mode 100644 index e162873..0000000 --- a/Makefile +++ /dev/null @@ -1,10 +0,0 @@ -CC=$(CROSS_COMPILE)gcc - -spl-image-builder: spl-image-builder.o - $(CC) -o $@ $< - -all: spl-image-builder - -clean: - rm -rf *.o - rm spl-image-builder diff --git a/chip-fel-fastboot.sh b/chip-fel-fastboot.sh deleted file mode 100755 index 8cdd67b..0000000 --- a/chip-fel-fastboot.sh +++ /dev/null @@ -1,132 +0,0 @@ -#!/bin/bash - -SCRIPTDIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd ) - -source $SCRIPTDIR/common.sh - -FEL=fel - -echo "BUILDROOT_OUTPUT_DIR = $BUILDROOT_OUTPUT_DIR" - -NAND_ERASE_BB=false -if [ "$1" == "erase-bb" ]; then - NAND_ERASE_BB=true -fi - -PATH=$PATH:$BUILDROOT_OUTPUT_DIR/host/usr/bin -TMPDIR=`mktemp -d -t chipflashXXXXXX` -PADDED_SPL="$TMPDIR/sunxi-padded-spl" -PADDED_SPL_SIZE=0 -UBOOT_SCRIPT="$TMPDIR/uboot.scr" -UBOOT_SCRIPT_MEM_ADDR=0x43100000 -UBOOT_SCRIPT_SRC="$TMPDIR/uboot.cmds" -SPL="$BUILDROOT_OUTPUT_DIR/images/sunxi-spl.bin" -SPL_MEM_ADDR=0x43000000 -UBOOT="$BUILDROOT_OUTPUT_DIR/images/u-boot-dtb.bin" -PADDED_UBOOT="$TMPDIR/padded-uboot" -PADDED_UBOOT_SIZE=0xc0000 -UBOOT_MEM_ADDR=0x4a000000 -UBI="$BUILDROOT_OUTPUT_DIR/images/rootfs.ubi" -UBI_MEM_ADDR=0x4b000000 - -UBI_SIZE=`filesize $UBI | xargs printf "0x%08x"` - -prepare_images() { - local in=$SPL - local out=$PADDED_SPL - - if [ -e "$out" ]; then - rm "$out" - fi - - # The BROM cannot read 16K pages: it only reads 8k of data at most. - # Split the SPL image in 8k chunks and pad each chunk with 8k of random - # data to limit the impact of repeated patterns on the MLC chip. - - dd if=$in of=$out bs=8k count=1 skip=0 conv=sync - dd if=/dev/urandom of=$out bs=8k count=1 seek=1 conv=sync - dd if=$in of=$out bs=8k count=1 skip=1 seek=2 conv=sync - dd if=/dev/urandom of=$out bs=8k count=1 seek=3 conv=sync - dd if=$in of=$out bs=8k count=1 skip=2 seek=4 conv=sync - dd if=/dev/urandom of=$out bs=8k count=1 seek=5 conv=sync - PADDED_SPL_SIZE=`filesize $out | xargs printf "0x%08x"` - - # Align the u-boot image on a page boundary - dd if=$UBOOT of=$PADDED_UBOOT bs=16k conv=sync - UBOOT_SIZE=`filesize $PADDED_UBOOT | xargs printf "0x%08x"` - dd if=/dev/urandom of=$PADDED_UBOOT seek=$((UBOOT_SIZE / 0x4000)) bs=16k count=$(((PADDED_UBOOT_SIZE - UBOOT_SIZE) / 0x4000)) -} - -prepare_uboot_script() { - if [ "$NAND_ERASE_BB" = true ] ; then - echo "nand scrub -y 0x0 0x200000000" > "${UBOOT_SCRIPT_SRC}" - else - echo "nand erase 0x0 0x200000000" > "${UBOOT_SCRIPT_SRC}" - fi - echo "sunxi_nand config spl" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x0 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x100000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x200000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x300000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x400000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x500000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x600000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $SPL_MEM_ADDR 0x700000 $PADDED_SPL_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "sunxi_nand config default" >> "${UBOOT_SCRIPT_SRC}" - echo "nand write $UBOOT_MEM_ADDR 0x800000 $PADDED_UBOOT_SIZE" >> "${UBOOT_SCRIPT_SRC}" - echo "setenv bootargs root=ubi0:rootfs rootfstype=ubifs rw earlyprintk ubi.mtd=4" >> "${UBOOT_SCRIPT_SRC}" - echo "setenv bootcmd 'source \${scriptaddr}; nand slc-mode on; mtdparts; ubi part UBI; ubifsmount ubi0:rootfs; ubifsload \$fdt_addr_r /boot/sun5i-r8-chip.dtb; ubifsload \$kernel_addr_r /boot/zImage; bootz \$kernel_addr_r - \$fdt_addr_r'" >> "${UBOOT_SCRIPT_SRC}" - echo "saveenv" >> "${UBOOT_SCRIPT_SRC}" - - echo "echo going to fastboot mode" >>"${UBOOT_SCRIPT_SRC}" - echo "fastboot 0" >>"${UBOOT_SCRIPT_SRC}" - echo "echo " >>"${UBOOT_SCRIPT_SRC}" - echo "echo *****************[ BOOT ]*****************" >>"${UBOOT_SCRIPT_SRC}" - echo "echo " >>"${UBOOT_SCRIPT_SRC}" - echo "boot" >>"${UBOOT_SCRIPT_SRC}" - - mkimage -A arm -T script -C none -n "flash CHIP" -d "$UBOOT_SCRIPT_SRC" "$UBOOT_SCRIPT" -} - -wait_for_fastboot() { - echo -n "waiting for fastboot..."; - for ((i=$TIMEOUT; i>0; i--)) { - if [[ ! -z "$(fastboot devices)" ]]; then - echo "OK"; - return 0; - fi - echo -n "."; - sleep 1 - } - - echo "TIMEOUT"; - return 1 -} - -echo == preparing images == -prepare_images -prepare_uboot_script - -echo == upload the SPL to SRAM and execute it == -${FEL} spl $SPL - -sleep 1 # wait for DRAM initialization to complete - -echo == upload spl == -${FEL} write $SPL_MEM_ADDR "$PADDED_SPL" -echo == upload u-boot == -${FEL} write $UBOOT_MEM_ADDR "$PADDED_UBOOT" -echo == upload u-boot script == -${FEL} write $UBOOT_SCRIPT_MEM_ADDR "$UBOOT_SCRIPT" - -echo == execute the main u-boot binary == -${FEL} exe $UBOOT_MEM_ADDR - -echo == waiting for fastboot == -if wait_for_fastboot; then - fastboot -S 0 -u flash UBI "${BUILDROOT_OUTPUT_DIR}/images/rootfs.ubi" - fastboot continue -else - rm -rf "${TMPDIR}" - exit 1 -fi diff --git a/spl-image-builder.c b/spl-image-builder.c deleted file mode 100644 index 9c23c05..0000000 --- a/spl-image-builder.c +++ /dev/null @@ -1,1730 +0,0 @@ -/* - * 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. - * - * Copyright © 2011 Parrot S.A. - * - * Author: Ivan Djelic - * - * Description: - * - * This library provides runtime configurable encoding/decoding of binary - * Bose-Chaudhuri-Hocquenghem (BCH) codes. - * - * Call init_bch to get a pointer to a newly allocated bch_control structure for - * the given m (Galois field order), t (error correction capability) and - * (optional) primitive polynomial parameters. - * - * Call encode_bch to compute and store ecc parity bytes to a given buffer. - * Call decode_bch to detect and locate errors in received data. - * - * On systems supporting hw BCH features, intermediate results may be provided - * to decode_bch in order to skip certain steps. See decode_bch() documentation - * for details. - * - * Option CONFIG_BCH_CONST_PARAMS can be used to force fixed values of - * parameters m and t; thus allowing extra compiler optimizations and providing - * better (up to 2x) encoding performance. Using this option makes sense when - * (m,t) are fixed and known in advance, e.g. when using BCH error correction - * on a particular NAND flash device. - * - * Algorithmic details: - * - * Encoding is performed by processing 32 input bits in parallel, using 4 - * remainder lookup tables. - * - * The final stage of decoding involves the following internal steps: - * a. Syndrome computation - * b. Error locator polynomial computation using Berlekamp-Massey algorithm - * c. Error locator root finding (by far the most expensive step) - * - * In this implementation, step c is not performed using the usual Chien search. - * Instead, an alternative approach described in [1] is used. It consists in - * factoring the error locator polynomial using the Berlekamp Trace algorithm - * (BTA) down to a certain degree (4), after which ad hoc low-degree polynomial - * solving techniques [2] are used. The resulting algorithm, called BTZ, yields - * much better performance than Chien search for usual (m,t) values (typically - * m >= 13, t < 32, see [1]). - * - * [1] B. Biswas, V. Herbert. Efficient root finding of polynomials over fields - * of characteristic 2, in: Western European Workshop on Research in Cryptology - * - WEWoRC 2009, Graz, Austria, LNCS, Springer, July 2009, to appear. - * [2] [Zin96] V.A. Zinoviev. On the solution of equations of degree 10 over - * finite fields GF(2^q). In Rapport de recherche INRIA no 2829, 1996. - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#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 repeat; - int disable_scrambler; - 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 = ((unsigned long)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; -} - -static inline int parity(unsigned int x) -{ - /* - * public domain code snippet, lifted from - * http://www-graphics.stanford.edu/~seander/bithacks.html - */ - x ^= x >> 1; - x ^= x >> 2; - x = (x & 0x11111111U) * 0x11111111U; - return (x >> 28) & 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 gf_div(struct bch_control *bch, unsigned int a, - unsigned int b) -{ - return a ? bch->a_pow_tab[mod_s(bch, bch->a_log_tab[a]+ - GF_N(bch)-bch->a_log_tab[b])] : 0; -} - -static inline unsigned int gf_inv(struct bch_control *bch, unsigned int a) -{ - return bch->a_pow_tab[GF_N(bch)-bch->a_log_tab[a]]; -} - -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]; -} - -static inline int a_ilog(struct bch_control *bch, unsigned int x) -{ - return mod_s(bch, GF_N(bch)-bch->a_log_tab[x]); -} - -/* - * compute 2t syndromes of ecc polynomial, i.e. ecc(a^j) for j=1..2t - */ -static void compute_syndromes(struct bch_control *bch, uint32_t *ecc, - unsigned int *syn) -{ - int i, j, s; - unsigned int m; - uint32_t poly; - const int t = GF_T(bch); - - s = bch->ecc_bits; - - /* make sure extra bits in last ecc word are cleared */ - m = ((unsigned int)s) & 31; - if (m) - ecc[s/32] &= ~((1u << (32-m))-1); - memset(syn, 0, 2*t*sizeof(*syn)); - - /* compute v(a^j) for j=1 .. 2t-1 */ - do { - poly = *ecc++; - s -= 32; - while (poly) { - i = deg(poly); - for (j = 0; j < 2*t; j += 2) - syn[j] ^= a_pow(bch, (j+1)*(i+s)); - - poly ^= (1 << i); - } - } while (s > 0); - - /* v(a^(2j)) = v(a^j)^2 */ - for (j = 0; j < t; j++) - syn[2*j+1] = gf_sqr(bch, syn[j]); -} - -static void gf_poly_copy(struct gf_poly *dst, struct gf_poly *src) -{ - memcpy(dst, src, GF_POLY_SZ(src->deg)); -} - -static int compute_error_locator_polynomial(struct bch_control *bch, - const unsigned int *syn) -{ - const unsigned int t = GF_T(bch); - const unsigned int n = GF_N(bch); - unsigned int i, j, tmp, l, pd = 1, d = syn[0]; - struct gf_poly *elp = bch->elp; - struct gf_poly *pelp = bch->poly_2t[0]; - struct gf_poly *elp_copy = bch->poly_2t[1]; - int k, pp = -1; - - memset(pelp, 0, GF_POLY_SZ(2*t)); - memset(elp, 0, GF_POLY_SZ(2*t)); - - pelp->deg = 0; - pelp->c[0] = 1; - elp->deg = 0; - elp->c[0] = 1; - - /* use simplified binary Berlekamp-Massey algorithm */ - for (i = 0; (i < t) && (elp->deg <= t); i++) { - if (d) { - k = 2*i-pp; - gf_poly_copy(elp_copy, elp); - /* e[i+1](X) = e[i](X)+di*dp^-1*X^2(i-p)*e[p](X) */ - tmp = a_log(bch, d)+n-a_log(bch, pd); - for (j = 0; j <= pelp->deg; j++) { - if (pelp->c[j]) { - l = a_log(bch, pelp->c[j]); - elp->c[j+k] ^= a_pow(bch, tmp+l); - } - } - /* compute l[i+1] = max(l[i]->c[l[p]+2*(i-p]) */ - tmp = pelp->deg+k; - if (tmp > elp->deg) { - elp->deg = tmp; - gf_poly_copy(pelp, elp_copy); - pd = d; - pp = 2*i; - } - } - /* di+1 = S(2i+3)+elp[i+1].1*S(2i+2)+...+elp[i+1].lS(2i+3-l) */ - if (i < t-1) { - d = syn[2*i+2]; - for (j = 1; j <= elp->deg; j++) - d ^= gf_mul(bch, elp->c[j], syn[2*i+2-j]); - } - } - dbg("elp=%s\n", gf_poly_str(elp)); - return (elp->deg > t) ? -1 : (int)elp->deg; -} - -/* - * solve a m x m linear system in GF(2) with an expected number of solutions, - * and return the number of found solutions - */ -static int solve_linear_system(struct bch_control *bch, unsigned int *rows, - unsigned int *sol, int nsol) -{ - const int m = GF_M(bch); - unsigned int tmp, mask; - int rem, c, r, p, k, param[m]; - - k = 0; - mask = 1 << m; - - /* Gaussian elimination */ - for (c = 0; c < m; c++) { - rem = 0; - p = c-k; - /* find suitable row for elimination */ - for (r = p; r < m; r++) { - if (rows[r] & mask) { - if (r != p) { - tmp = rows[r]; - rows[r] = rows[p]; - rows[p] = tmp; - } - rem = r+1; - break; - } - } - if (rem) { - /* perform elimination on remaining rows */ - tmp = rows[p]; - for (r = rem; r < m; r++) { - if (rows[r] & mask) - rows[r] ^= tmp; - } - } else { - /* elimination not needed, store defective row index */ - param[k++] = c; - } - mask >>= 1; - } - /* rewrite system, inserting fake parameter rows */ - if (k > 0) { - p = k; - for (r = m-1; r >= 0; r--) { - if ((r > m-1-k) && rows[r]) - /* system has no solution */ - return 0; - - rows[r] = (p && (r == param[p-1])) ? - p--, 1u << (m-r) : rows[r-p]; - } - } - - if (nsol != (1 << k)) - /* unexpected number of solutions */ - return 0; - - for (p = 0; p < nsol; p++) { - /* set parameters for p-th solution */ - for (c = 0; c < k; c++) - rows[param[c]] = (rows[param[c]] & ~1)|((p >> c) & 1); - - /* compute unique solution */ - tmp = 0; - for (r = m-1; r >= 0; r--) { - mask = rows[r] & (tmp|1); - tmp |= parity(mask) << (m-r); - } - sol[p] = tmp >> 1; - } - return nsol; -} - -/* - * this function builds and solves a linear system for finding roots of a degree - * 4 affine monic polynomial X^4+aX^2+bX+c over GF(2^m). - */ -static int find_affine4_roots(struct bch_control *bch, unsigned int a, - unsigned int b, unsigned int c, - unsigned int *roots) -{ - int i, j, k; - const int m = GF_M(bch); - unsigned int mask = 0xff, t, rows[16] = {0,}; - - j = a_log(bch, b); - k = a_log(bch, a); - rows[0] = c; - - /* buid linear system to solve X^4+aX^2+bX+c = 0 */ - for (i = 0; i < m; i++) { - rows[i+1] = bch->a_pow_tab[4*i]^ - (a ? bch->a_pow_tab[mod_s(bch, k)] : 0)^ - (b ? bch->a_pow_tab[mod_s(bch, j)] : 0); - j++; - k += 2; - } - /* - * transpose 16x16 matrix before passing it to linear solver - * warning: this code assumes m < 16 - */ - for (j = 8; j != 0; j >>= 1, mask ^= (mask << j)) { - for (k = 0; k < 16; k = (k+j+1) & ~j) { - t = ((rows[k] >> j)^rows[k+j]) & mask; - rows[k] ^= (t << j); - rows[k+j] ^= t; - } - } - return solve_linear_system(bch, rows, roots, 4); -} - -/* - * compute root r of a degree 1 polynomial over GF(2^m) (returned as log(1/r)) - */ -static int find_poly_deg1_roots(struct bch_control *bch, struct gf_poly *poly, - unsigned int *roots) -{ - int n = 0; - - if (poly->c[0]) - /* poly[X] = bX+c with c!=0, root=c/b */ - roots[n++] = mod_s(bch, GF_N(bch)-bch->a_log_tab[poly->c[0]]+ - bch->a_log_tab[poly->c[1]]); - return n; -} - -/* - * compute roots of a degree 2 polynomial over GF(2^m) - */ -static int find_poly_deg2_roots(struct bch_control *bch, struct gf_poly *poly, - unsigned int *roots) -{ - int n = 0, i, l0, l1, l2; - unsigned int u, v, r; - - if (poly->c[0] && poly->c[1]) { - - l0 = bch->a_log_tab[poly->c[0]]; - l1 = bch->a_log_tab[poly->c[1]]; - l2 = bch->a_log_tab[poly->c[2]]; - - /* using z=a/bX, transform aX^2+bX+c into z^2+z+u (u=ac/b^2) */ - u = a_pow(bch, l0+l2+2*(GF_N(bch)-l1)); - /* - * let u = sum(li.a^i) i=0..m-1; then compute r = sum(li.xi): - * r^2+r = sum(li.(xi^2+xi)) = sum(li.(a^i+Tr(a^i).a^k)) = - * u + sum(li.Tr(a^i).a^k) = u+a^k.Tr(sum(li.a^i)) = u+a^k.Tr(u) - * i.e. r and r+1 are roots iff Tr(u)=0 - */ - r = 0; - v = u; - while (v) { - i = deg(v); - r ^= bch->xi_tab[i]; - v ^= (1 << i); - } - /* verify root */ - if ((gf_sqr(bch, r)^r) == u) { - /* reverse z=a/bX transformation and compute log(1/r) */ - roots[n++] = modulo(bch, 2*GF_N(bch)-l1- - bch->a_log_tab[r]+l2); - roots[n++] = modulo(bch, 2*GF_N(bch)-l1- - bch->a_log_tab[r^1]+l2); - } - } - return n; -} - -/* - * compute roots of a degree 3 polynomial over GF(2^m) - */ -static int find_poly_deg3_roots(struct bch_control *bch, struct gf_poly *poly, - unsigned int *roots) -{ - int i, n = 0; - unsigned int a, b, c, a2, b2, c2, e3, tmp[4]; - - if (poly->c[0]) { - /* transform polynomial into monic X^3 + a2X^2 + b2X + c2 */ - e3 = poly->c[3]; - c2 = gf_div(bch, poly->c[0], e3); - b2 = gf_div(bch, poly->c[1], e3); - a2 = gf_div(bch, poly->c[2], e3); - - /* (X+a2)(X^3+a2X^2+b2X+c2) = X^4+aX^2+bX+c (affine) */ - c = gf_mul(bch, a2, c2); /* c = a2c2 */ - b = gf_mul(bch, a2, b2)^c2; /* b = a2b2 + c2 */ - a = gf_sqr(bch, a2)^b2; /* a = a2^2 + b2 */ - - /* find the 4 roots of this affine polynomial */ - if (find_affine4_roots(bch, a, b, c, tmp) == 4) { - /* remove a2 from final list of roots */ - for (i = 0; i < 4; i++) { - if (tmp[i] != a2) - roots[n++] = a_ilog(bch, tmp[i]); - } - } - } - return n; -} - -/* - * compute roots of a degree 4 polynomial over GF(2^m) - */ -static int find_poly_deg4_roots(struct bch_control *bch, struct gf_poly *poly, - unsigned int *roots) -{ - int i, l, n = 0; - unsigned int a, b, c, d, e = 0, f, a2, b2, c2, e4; - - if (poly->c[0] == 0) - return 0; - - /* transform polynomial into monic X^4 + aX^3 + bX^2 + cX + d */ - e4 = poly->c[4]; - d = gf_div(bch, poly->c[0], e4); - c = gf_div(bch, poly->c[1], e4); - b = gf_div(bch, poly->c[2], e4); - a = gf_div(bch, poly->c[3], e4); - - /* use Y=1/X transformation to get an affine polynomial */ - if (a) { - /* first, eliminate cX by using z=X+e with ae^2+c=0 */ - if (c) { - /* compute e such that e^2 = c/a */ - f = gf_div(bch, c, a); - l = a_log(bch, f); - l += (l & 1) ? GF_N(bch) : 0; - e = a_pow(bch, l/2); - /* - * use transformation z=X+e: - * z^4+e^4 + a(z^3+ez^2+e^2z+e^3) + b(z^2+e^2) +cz+ce+d - * z^4 + az^3 + (ae+b)z^2 + (ae^2+c)z+e^4+be^2+ae^3+ce+d - * z^4 + az^3 + (ae+b)z^2 + e^4+be^2+d - * z^4 + az^3 + b'z^2 + d' - */ - d = a_pow(bch, 2*l)^gf_mul(bch, b, f)^d; - b = gf_mul(bch, a, e)^b; - } - /* now, use Y=1/X to get Y^4 + b/dY^2 + a/dY + 1/d */ - if (d == 0) - /* assume all roots have multiplicity 1 */ - return 0; - - c2 = gf_inv(bch, d); - b2 = gf_div(bch, a, d); - a2 = gf_div(bch, b, d); - } else { - /* polynomial is already affine */ - c2 = d; - b2 = c; - a2 = b; - } - /* find the 4 roots of this affine polynomial */ - if (find_affine4_roots(bch, a2, b2, c2, roots) == 4) { - for (i = 0; i < 4; i++) { - /* post-process roots (reverse transformations) */ - f = a ? gf_inv(bch, roots[i]) : roots[i]; - roots[i] = a_ilog(bch, f^e); - } - n = 4; - } - return n; -} - -/* - * build monic, log-based representation of a polynomial - */ -static void gf_poly_logrep(struct bch_control *bch, - const struct gf_poly *a, int *rep) -{ - int i, d = a->deg, l = GF_N(bch)-a_log(bch, a->c[a->deg]); - - /* represent 0 values with -1; warning, rep[d] is not set to 1 */ - for (i = 0; i < d; i++) - rep[i] = a->c[i] ? mod_s(bch, a_log(bch, a->c[i])+l) : -1; -} - -/* - * compute polynomial Euclidean division remainder in GF(2^m)[X] - */ -static void gf_poly_mod(struct bch_control *bch, struct gf_poly *a, - const struct gf_poly *b, int *rep) -{ - int la, p, m; - unsigned int i, j, *c = a->c; - const unsigned int d = b->deg; - - if (a->deg < d) - return; - - /* reuse or compute log representation of denominator */ - if (!rep) { - rep = bch->cache; - gf_poly_logrep(bch, b, rep); - } - - for (j = a->deg; j >= d; j--) { - if (c[j]) { - la = a_log(bch, c[j]); - p = j-d; - for (i = 0; i < d; i++, p++) { - m = rep[i]; - if (m >= 0) - c[p] ^= bch->a_pow_tab[mod_s(bch, - m+la)]; - } - } - } - a->deg = d-1; - while (!c[a->deg] && a->deg) - a->deg--; -} - -/* - * compute polynomial Euclidean division quotient in GF(2^m)[X] - */ -static void gf_poly_div(struct bch_control *bch, struct gf_poly *a, - const struct gf_poly *b, struct gf_poly *q) -{ - if (a->deg >= b->deg) { - q->deg = a->deg-b->deg; - /* compute a mod b (modifies a) */ - gf_poly_mod(bch, a, b, NULL); - /* quotient is stored in upper part of polynomial a */ - memcpy(q->c, &a->c[b->deg], (1+q->deg)*sizeof(unsigned int)); - } else { - q->deg = 0; - q->c[0] = 0; - } -} - -/* - * compute polynomial GCD (Greatest Common Divisor) in GF(2^m)[X] - */ -static struct gf_poly *gf_poly_gcd(struct bch_control *bch, struct gf_poly *a, - struct gf_poly *b) -{ - struct gf_poly *tmp; - - dbg("gcd(%s,%s)=", gf_poly_str(a), gf_poly_str(b)); - - if (a->deg < b->deg) { - tmp = b; - b = a; - a = tmp; - } - - while (b->deg > 0) { - gf_poly_mod(bch, a, b, NULL); - tmp = b; - b = a; - a = tmp; - } - - dbg("%s\n", gf_poly_str(a)); - - return a; -} - -/* - * Given a polynomial f and an integer k, compute Tr(a^kX) mod f - * This is used in Berlekamp Trace algorithm for splitting polynomials - */ -static void compute_trace_bk_mod(struct bch_control *bch, int k, - const struct gf_poly *f, struct gf_poly *z, - struct gf_poly *out) -{ - const int m = GF_M(bch); - int i, j; - - /* z contains z^2j mod f */ - z->deg = 1; - z->c[0] = 0; - z->c[1] = bch->a_pow_tab[k]; - - out->deg = 0; - memset(out, 0, GF_POLY_SZ(f->deg)); - - /* compute f log representation only once */ - gf_poly_logrep(bch, f, bch->cache); - - for (i = 0; i < m; i++) { - /* add a^(k*2^i)(z^(2^i) mod f) and compute (z^(2^i) mod f)^2 */ - for (j = z->deg; j >= 0; j--) { - out->c[j] ^= z->c[j]; - z->c[2*j] = gf_sqr(bch, z->c[j]); - z->c[2*j+1] = 0; - } - if (z->deg > out->deg) - out->deg = z->deg; - - if (i < m-1) { - z->deg *= 2; - /* z^(2(i+1)) mod f = (z^(2^i) mod f)^2 mod f */ - gf_poly_mod(bch, z, f, bch->cache); - } - } - while (!out->c[out->deg] && out->deg) - out->deg--; - - dbg("Tr(a^%d.X) mod f = %s\n", k, gf_poly_str(out)); -} - -/* - * factor a polynomial using Berlekamp Trace algorithm (BTA) - */ -static void factor_polynomial(struct bch_control *bch, int k, struct gf_poly *f, - struct gf_poly **g, struct gf_poly **h) -{ - struct gf_poly *f2 = bch->poly_2t[0]; - struct gf_poly *q = bch->poly_2t[1]; - struct gf_poly *tk = bch->poly_2t[2]; - struct gf_poly *z = bch->poly_2t[3]; - struct gf_poly *gcd; - - dbg("factoring %s...\n", gf_poly_str(f)); - - *g = f; - *h = NULL; - - /* tk = Tr(a^k.X) mod f */ - compute_trace_bk_mod(bch, k, f, z, tk); - - if (tk->deg > 0) { - /* compute g = gcd(f, tk) (destructive operation) */ - gf_poly_copy(f2, f); - gcd = gf_poly_gcd(bch, f2, tk); - if (gcd->deg < f->deg) { - /* compute h=f/gcd(f,tk); this will modify f and q */ - gf_poly_div(bch, f, gcd, q); - /* store g and h in-place (clobbering f) */ - *h = &((struct gf_poly_deg1 *)f)[gcd->deg].poly; - gf_poly_copy(*g, gcd); - gf_poly_copy(*h, q); - } - } -} - -/* - * find roots of a polynomial, using BTZ algorithm; see the beginning of this - * file for details - */ -static int find_poly_roots(struct bch_control *bch, unsigned int k, - struct gf_poly *poly, unsigned int *roots) -{ - int cnt; - struct gf_poly *f1, *f2; - - switch (poly->deg) { - /* handle low degree polynomials with ad hoc techniques */ - case 1: - cnt = find_poly_deg1_roots(bch, poly, roots); - break; - case 2: - cnt = find_poly_deg2_roots(bch, poly, roots); - break; - case 3: - cnt = find_poly_deg3_roots(bch, poly, roots); - break; - case 4: - cnt = find_poly_deg4_roots(bch, poly, roots); - break; - default: - /* factor polynomial using Berlekamp Trace Algorithm (BTA) */ - cnt = 0; - if (poly->deg && (k <= GF_M(bch))) { - factor_polynomial(bch, k, poly, &f1, &f2); - if (f1) - cnt += find_poly_roots(bch, k+1, f1, roots); - if (f2) - cnt += find_poly_roots(bch, k+1, f2, roots+cnt); - } - break; - } - return cnt; -} - -#if defined(USE_CHIEN_SEARCH) -/* - * exhaustive root search (Chien) implementation - not used, included only for - * reference/comparison tests - */ -static int chien_search(struct bch_control *bch, unsigned int len, - struct gf_poly *p, unsigned int *roots) -{ - int m; - unsigned int i, j, syn, syn0, count = 0; - const unsigned int k = 8*len+bch->ecc_bits; - - /* use a log-based representation of polynomial */ - gf_poly_logrep(bch, p, bch->cache); - bch->cache[p->deg] = 0; - syn0 = gf_div(bch, p->c[0], p->c[p->deg]); - - for (i = GF_N(bch)-k+1; i <= GF_N(bch); i++) { - /* compute elp(a^i) */ - for (j = 1, syn = syn0; j <= p->deg; j++) { - m = bch->cache[j]; - if (m >= 0) - syn ^= a_pow(bch, m+j*i); - } - if (syn == 0) { - roots[count++] = GF_N(bch)-i; - if (count == p->deg) - break; - } - } - return (count == p->deg) ? count : 0; -} -#define find_poly_roots(_p, _k, _elp, _loc) chien_search(_p, len, _elp, _loc) -#endif /* USE_CHIEN_SEARCH */ - -/** - * decode_bch - decode received codeword and find bit error locations - * @bch: BCH control structure - * @data: received data, ignored if @calc_ecc is provided - * @len: data length in bytes, must always be provided - * @recv_ecc: received ecc, if NULL then assume it was XORed in @calc_ecc - * @calc_ecc: calculated ecc, if NULL then calc_ecc is computed from @data - * @syn: hw computed syndrome data (if NULL, syndrome is calculated) - * @errloc: output array of error locations - * - * Returns: - * The number of errors found, or -EBADMSG if decoding failed, or -EINVAL if - * invalid parameters were provided - * - * Depending on the available hw BCH support and the need to compute @calc_ecc - * separately (using encode_bch()), this function should be called with one of - * the following parameter configurations - - * - * by providing @data and @recv_ecc only: - * decode_bch(@bch, @data, @len, @recv_ecc, NULL, NULL, @errloc) - * - * by providing @recv_ecc and @calc_ecc: - * decode_bch(@bch, NULL, @len, @recv_ecc, @calc_ecc, NULL, @errloc) - * - * by providing ecc = recv_ecc XOR calc_ecc: - * decode_bch(@bch, NULL, @len, NULL, ecc, NULL, @errloc) - * - * by providing syndrome results @syn: - * decode_bch(@bch, NULL, @len, NULL, NULL, @syn, @errloc) - * - * Once decode_bch() has successfully returned with a positive value, error - * locations returned in array @errloc should be interpreted as follows - - * - * if (errloc[n] >= 8*len), then n-th error is located in ecc (no need for - * data correction) - * - * if (errloc[n] < 8*len), then n-th error is located in data and can be - * corrected with statement data[errloc[n]/8] ^= 1 << (errloc[n] % 8); - * - * Note that this function does not perform any data correction by itself, it - * merely indicates error locations. - */ -static int decode_bch(struct bch_control *bch, - const uint8_t *data, unsigned int len, - const uint8_t *recv_ecc, const uint8_t *calc_ecc, - const unsigned int *syn, unsigned int *errloc) -{ - const unsigned int ecc_words = BCH_ECC_WORDS(bch); - unsigned int nbits; - int i, err, nroots; - uint32_t sum; - - /* sanity check: make sure data length can be handled */ - if (8*len > (bch->n-bch->ecc_bits)) - return -EINVAL; - - /* if caller does not provide syndromes, compute them */ - if (!syn) { - if (!calc_ecc) { - /* compute received data ecc into an internal buffer */ - if (!data || !recv_ecc) - return -EINVAL; - encode_bch(bch, data, len, NULL); - } else { - /* load provided calculated ecc */ - load_ecc8(bch, bch->ecc_buf, calc_ecc); - } - /* load received ecc or assume it was XORed in calc_ecc */ - if (recv_ecc) { - load_ecc8(bch, bch->ecc_buf2, recv_ecc); - /* XOR received and calculated ecc */ - for (i = 0, sum = 0; i < (int)ecc_words; i++) { - bch->ecc_buf[i] ^= bch->ecc_buf2[i]; - sum |= bch->ecc_buf[i]; - } - if (!sum) - /* no error found */ - return 0; - } - compute_syndromes(bch, bch->ecc_buf, bch->syn); - syn = bch->syn; - } - - err = compute_error_locator_polynomial(bch, syn); - if (err > 0) { - nroots = find_poly_roots(bch, 1, bch->elp, errloc); - if (err != nroots) - err = -1; - } - if (err > 0) { - /* post-process raw error locations for easier correction */ - nbits = (len*8)+bch->ecc_bits; - for (i = 0; i < err; i++) { - if (errloc[i] >= nbits) { - err = -1; - break; - } - errloc[i] = nbits-1-errloc[i]; - errloc[i] = (errloc[i] & ~7)|(7-(errloc[i] & 7)); - } - } - return (err >= 0) ? err : -EBADMSG; -} - -/* - * 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 0a_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) -{ - uint8_t res = 0; - 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) -{ - int seedidx = page % ARRAY_SIZE(default_scrambler_seeds); - uint16_t state; - int i; - - /* First pass: scramble data with the BROM seed */ - state = lfsr_step(brom_scrambler_seeds[0], 15); - for (i = 0; i < datalen; i++) { - uint8_t old = data[i]; - data[i] ^= state; - state = lfsr_step(state, 8); - } - - if (info->disable_scrambler) - return; - - /* - * Second pass: scramble data with the default seed to - * to revert the default randomization used by Linux. - */ - state = lfsr_step(default_scrambler_seeds[seedidx], 15); - for (i = 0; i < datalen; i++) { - data[i] ^= state; - state = lfsr_step(state, 8); - } -} - -static int create_image(const struct image_info *info) -{ - struct bch_control *bch; - uint8_t *data, *ecc, *buffer; - int eccbytes = DIV_ROUND_UP(info->ecc_strength * 14, 8); - int pagepadsize = info->page_size - info->usable_page_size; - int data_steps = info->usable_page_size / info->ecc_step_size; - int usable_page_size = data_steps * - (info->ecc_step_size + 4 + eccbytes); - int page = 0, page_offset = 0; - FILE *src, *dst, *rnd; - int repeat = info->repeat; - - bch = init_bch(14, info->ecc_strength, BCH_PRIMITIVE_POLY); - if (!bch) { - printf("Failed to init the BCH engine\n"); - return -1; - } - - buffer = malloc(info->page_size + info->oob_size); - if (!buffer) { - printf("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) { - printf("Failed to open source file (%s)\n", info->source); - return -1; - } - - dst = fopen(info->dest, "w"); - if (!dst) { - printf("Failed to open dest file (%s)\n", info->dest); - return -1; - } - - rnd = fopen("/dev/urandom", "r"); - if (!rnd) { - printf("Failed to open /dev/urandom\n"); - return -1; - } - - if (usable_page_size < info->page_size + info->oob_size) { - fread(buffer + usable_page_size, 1, - info->page_size + info->oob_size - usable_page_size, - rnd); - memset(buffer + info->page_size, 0xff, 2); - } - - while (1) { - size_t cnt, srcpadsize; - - cnt = info->ecc_step_size; - - data = buffer + page_offset; - ecc = buffer + page_offset + info->ecc_step_size + 4; - cnt = fread(data, 1, info->ecc_step_size, src); - if (!cnt && !feof(src)) { - printf("Failed to read data from the source\n"); - return -1; - } - - /* - * If page_offset != 0 continue (fill the rest of the page with - * random data) to make sure the entire page has valid ecc data - */ - if (page_offset == 0 && cnt == 0) { - if (!repeat--) - break; - - memset(buffer, 0xff, info->page_size + info->oob_size); - while (page % 0x40) { - fwrite(buffer, - info->page_size + info->oob_size, - 1, dst); - page++; - } - - page_offset = 0; - fseek(src, 0, SEEK_SET); - continue; - } - - srcpadsize = info->ecc_step_size - cnt; - if (srcpadsize) - fread(data + cnt, 1, srcpadsize, rnd); - - memset(ecc, 0, eccbytes); - swap_bits(data, info->ecc_step_size + 4); - encode_bch(bch, data, info->ecc_step_size + 4, ecc); - swap_bits(data, info->ecc_step_size + 4); - swap_bits(ecc, eccbytes); - scramble(info, page, data, info->ecc_step_size + 4 + eccbytes); - - page_offset += info->ecc_step_size + 4 + eccbytes; - if (page_offset >= usable_page_size) { - fwrite(buffer, info->page_size + info->oob_size, 1, dst); - memset(buffer, 0xff, info->page_size + info->oob_size); - page++; - page_offset = 0; - if (usable_page_size < info->page_size + info->oob_size) { - fread(buffer + usable_page_size, 1, - info->page_size + info->oob_size - - usable_page_size, - rnd); - memset(buffer + info->page_size, 0xff, 2); - } - } - } - - return 0; -} - -static void display_help(int status) -{ - fprintf(status == EXIT_SUCCESS ? stdout : stderr, -"Usage: spl-image-builder [OPTIONS] source-image output-image\n" -"Creates an image fitting the BROM requirements (randomizer and ECC config).\n" -"\n" -"-h --help Display this help and exit\n" -"-s strength --ecc-strength=size ECC strength\n" -"-c size --ecc-step-size=size ECC step size\n" -"-p size --page-size=size Page size\n" -"-o size --oob-size=size OOB size\n" -"-u size --usable-page-size=size Usable page size\n" -"-r num --repeat=num Number of redundant SPL images\n" -"-d --disable-scrambler Disable the second scrambling pass\n" -"\n"); - exit(status); -} - -int main(int argc, char **argv) -{ - struct image_info info; - - memset(&info, 0, sizeof(info)); - /* - * Process user arguments - */ - for (;;) { - int option_index = 0; - static const char *short_options = "jNqu"; - static const struct option long_options[] = { - {"help", no_argument, 0, 0}, - {"ecc-strength", required_argument, 0, 's'}, - {"ecc-step-size", required_argument, 0, 'c'}, - {"page-size", required_argument, 0, 'p'}, - {"oob-size", required_argument, 0, 'o'}, - {"usable-page-size", required_argument, 0, 'u'}, - {"repeat", required_argument, 0, 'r'}, - {"disable-scrambler", no_argument, 0, 'd'}, - {0, 0, 0, 0}, - }; - - int c = getopt_long(argc, argv, "s:c:p:o:u:r:d", - long_options, &option_index); - if (c == EOF) - break; - - switch (c) { - case 'h': - display_help(0); - break; - case 's': - info.ecc_strength = strtol(optarg, NULL, 0); - break; - case 'c': - info.ecc_step_size = strtol(optarg, 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 'r': - info.repeat = strtol(optarg, NULL, 0); - if (info.repeat > 7) - info.repeat = 7; - break; - case 'd': - info.disable_scrambler = 1; - break; - case '?': - display_help(-1); - break; - } - } - - if ((argc - optind) != 2) - display_help(-1); - - info.source = argv[optind]; - info.dest = argv[optind + 1]; - - return create_image(&info); -}