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- add missing svn props from svn 1768 commit 

git-svn-id: svn://svn.berlios.de/openocd/trunk@1769 b42882b7-edfa-0310-969c-e2dbd0fdcd60
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ntfreak 2009-05-12 18:32:57 +00:00
parent cbfa0304f9
commit b7b586ac6b
1 changed files with 174 additions and 174 deletions
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src/flash/nand_ecc_kw.c
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@ -1,174 +1,174 @@
/* /*
* Reed-Solomon ECC handling for the Marvell Kirkwood SOC * Reed-Solomon ECC handling for the Marvell Kirkwood SOC
* Copyright (C) 2009 Marvell Semiconductor, Inc. * Copyright (C) 2009 Marvell Semiconductor, Inc.
* *
* Authors: Lennert Buytenhek <buytenh@wantstofly.org> * Authors: Lennert Buytenhek <buytenh@wantstofly.org>
* Nicolas Pitre <nico@cam.org> * Nicolas Pitre <nico@cam.org>
* *
* This file is free software; you can redistribute it and/or modify it * This file is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the * under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 or (at your option) any * Free Software Foundation; either version 2 or (at your option) any
* later version. * later version.
* *
* This file is distributed in the hope that it will be useful, but WITHOUT * This file is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details. * for more details.
*/ */
#ifdef HAVE_CONFIG_H #ifdef HAVE_CONFIG_H
#include "config.h" #include "config.h"
#endif #endif
#include <sys/types.h> #include <sys/types.h>
#include "nand.h" #include "nand.h"
/***************************************************************************** /*****************************************************************************
* Arithmetic in GF(2^10) ("F") modulo x^10 + x^3 + 1. * Arithmetic in GF(2^10) ("F") modulo x^10 + x^3 + 1.
* *
* For multiplication, a discrete log/exponent table is used, with * For multiplication, a discrete log/exponent table is used, with
* primitive element x (F is a primitive field, so x is primitive). * primitive element x (F is a primitive field, so x is primitive).
*/ */
#define MODPOLY 0x409 /* x^10 + x^3 + 1 in binary */ #define MODPOLY 0x409 /* x^10 + x^3 + 1 in binary */
/* /*
* Maps an integer a [0..1022] to a polynomial b = gf_exp[a] in * Maps an integer a [0..1022] to a polynomial b = gf_exp[a] in
* GF(2^10) mod x^10 + x^3 + 1 such that b = x ^ a. There's two * GF(2^10) mod x^10 + x^3 + 1 such that b = x ^ a. There's two
* identical copies of this array back-to-back so that we can save * identical copies of this array back-to-back so that we can save
* the mod 1023 operation when doing a GF multiplication. * the mod 1023 operation when doing a GF multiplication.
*/ */
static uint16_t gf_exp[1023 + 1023]; static uint16_t gf_exp[1023 + 1023];
/* /*
* Maps a polynomial b in GF(2^10) mod x^10 + x^3 + 1 to an index * Maps a polynomial b in GF(2^10) mod x^10 + x^3 + 1 to an index
* a = gf_log[b] in [0..1022] such that b = x ^ a. * a = gf_log[b] in [0..1022] such that b = x ^ a.
*/ */
static uint16_t gf_log[1024]; static uint16_t gf_log[1024];
static void gf_build_log_exp_table(void) static void gf_build_log_exp_table(void)
{ {
int i; int i;
int p_i; int p_i;
/* /*
* p_i = x ^ i * p_i = x ^ i
* *
* Initialise to 1 for i = 0. * Initialise to 1 for i = 0.
*/ */
p_i = 1; p_i = 1;
for (i = 0; i < 1023; i++) { for (i = 0; i < 1023; i++) {
gf_exp[i] = p_i; gf_exp[i] = p_i;
gf_exp[i + 1023] = p_i; gf_exp[i + 1023] = p_i;
gf_log[p_i] = i; gf_log[p_i] = i;
/* /*
* p_i = p_i * x * p_i = p_i * x
*/ */
p_i <<= 1; p_i <<= 1;
if (p_i & (1 << 10)) if (p_i & (1 << 10))
p_i ^= MODPOLY; p_i ^= MODPOLY;
} }
} }
/***************************************************************************** /*****************************************************************************
* Reed-Solomon code * Reed-Solomon code
* *
* This implements a (1023,1015) Reed-Solomon ECC code over GF(2^10) * This implements a (1023,1015) Reed-Solomon ECC code over GF(2^10)
* mod x^10 + x^3 + 1, shortened to (520,512). The ECC data consists * mod x^10 + x^3 + 1, shortened to (520,512). The ECC data consists
* of 8 10-bit symbols, or 10 8-bit bytes. * of 8 10-bit symbols, or 10 8-bit bytes.
* *
* Given 512 bytes of data, computes 10 bytes of ECC. * Given 512 bytes of data, computes 10 bytes of ECC.
* *
* This is done by converting the 512 bytes to 512 10-bit symbols * This is done by converting the 512 bytes to 512 10-bit symbols
* (elements of F), interpreting those symbols as a polynomial in F[X] * (elements of F), interpreting those symbols as a polynomial in F[X]
* by taking symbol 0 as the coefficient of X^8 and symbol 511 as the * by taking symbol 0 as the coefficient of X^8 and symbol 511 as the
* coefficient of X^519, and calculating the residue of that polynomial * coefficient of X^519, and calculating the residue of that polynomial
* divided by the generator polynomial, which gives us the 8 ECC symbols * divided by the generator polynomial, which gives us the 8 ECC symbols
* as the remainder. Finally, we convert the 8 10-bit ECC symbols to 10 * as the remainder. Finally, we convert the 8 10-bit ECC symbols to 10
* 8-bit bytes. * 8-bit bytes.
* *
* The generator polynomial is hardcoded, as that is faster, but it * The generator polynomial is hardcoded, as that is faster, but it
* can be computed by taking the primitive element a = x (in F), and * can be computed by taking the primitive element a = x (in F), and
* constructing a polynomial in F[X] with roots a, a^2, a^3, ..., a^8 * constructing a polynomial in F[X] with roots a, a^2, a^3, ..., a^8
* by multiplying the minimal polynomials for those roots (which are * by multiplying the minimal polynomials for those roots (which are
* just 'x - a^i' for each i). * just 'x - a^i' for each i).
* *
* Note: due to unfortunate circumstances, the bootrom in the Kirkwood SOC * Note: due to unfortunate circumstances, the bootrom in the Kirkwood SOC
* expects the ECC to be computed backward, i.e. from the last byte down * expects the ECC to be computed backward, i.e. from the last byte down
* to the first one. * to the first one.
*/ */
int nand_calculate_ecc_kw(struct nand_device_s *device, const u8 *data, u8 *ecc) int nand_calculate_ecc_kw(struct nand_device_s *device, const u8 *data, u8 *ecc)
{ {
unsigned int r7, r6, r5, r4, r3, r2, r1, r0; unsigned int r7, r6, r5, r4, r3, r2, r1, r0;
int i; int i;
static int tables_initialized = 0; static int tables_initialized = 0;
if (!tables_initialized) { if (!tables_initialized) {
gf_build_log_exp_table(); gf_build_log_exp_table();
tables_initialized = 1; tables_initialized = 1;
} }
/* /*
* Load bytes 504..511 of the data into r. * Load bytes 504..511 of the data into r.
*/ */
r0 = data[504]; r0 = data[504];
r1 = data[505]; r1 = data[505];
r2 = data[506]; r2 = data[506];
r3 = data[507]; r3 = data[507];
r4 = data[508]; r4 = data[508];
r5 = data[509]; r5 = data[509];
r6 = data[510]; r6 = data[510];
r7 = data[511]; r7 = data[511];
/* /*
* Shift bytes 503..0 (in that order) into r0, followed * Shift bytes 503..0 (in that order) into r0, followed
* by eight zero bytes, while reducing the polynomial by the * by eight zero bytes, while reducing the polynomial by the
* generator polynomial in every step. * generator polynomial in every step.
*/ */
for (i = 503; i >= -8; i--) { for (i = 503; i >= -8; i--) {
unsigned int d; unsigned int d;
d = 0; d = 0;
if (i >= 0) if (i >= 0)
d = data[i]; d = data[i];
if (r7) { if (r7) {
u16 *t = gf_exp + gf_log[r7]; u16 *t = gf_exp + gf_log[r7];
r7 = r6 ^ t[0x21c]; r7 = r6 ^ t[0x21c];
r6 = r5 ^ t[0x181]; r6 = r5 ^ t[0x181];
r5 = r4 ^ t[0x18e]; r5 = r4 ^ t[0x18e];
r4 = r3 ^ t[0x25f]; r4 = r3 ^ t[0x25f];
r3 = r2 ^ t[0x197]; r3 = r2 ^ t[0x197];
r2 = r1 ^ t[0x193]; r2 = r1 ^ t[0x193];
r1 = r0 ^ t[0x237]; r1 = r0 ^ t[0x237];
r0 = d ^ t[0x024]; r0 = d ^ t[0x024];
} else { } else {
r7 = r6; r7 = r6;
r6 = r5; r6 = r5;
r5 = r4; r5 = r4;
r4 = r3; r4 = r3;
r3 = r2; r3 = r2;
r2 = r1; r2 = r1;
r1 = r0; r1 = r0;
r0 = d; r0 = d;
} }
} }
ecc[0] = r0; ecc[0] = r0;
ecc[1] = (r0 >> 8) | (r1 << 2); ecc[1] = (r0 >> 8) | (r1 << 2);
ecc[2] = (r1 >> 6) | (r2 << 4); ecc[2] = (r1 >> 6) | (r2 << 4);
ecc[3] = (r2 >> 4) | (r3 << 6); ecc[3] = (r2 >> 4) | (r3 << 6);
ecc[4] = (r3 >> 2); ecc[4] = (r3 >> 2);
ecc[5] = r4; ecc[5] = r4;
ecc[6] = (r4 >> 8) | (r5 << 2); ecc[6] = (r4 >> 8) | (r5 << 2);
ecc[7] = (r5 >> 6) | (r6 << 4); ecc[7] = (r5 >> 6) | (r6 << 4);
ecc[8] = (r6 >> 4) | (r7 << 6); ecc[8] = (r6 >> 4) | (r7 << 6);
ecc[9] = (r7 >> 2); ecc[9] = (r7 >> 2);
return 0; return 0;
} }