summaryrefslogtreecommitdiff
path: root/ubi-utils/src/nandecc.c
diff options
context:
space:
mode:
authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2008-02-19 14:54:17 +0200
committerArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2008-02-19 16:41:16 +0200
commit86dd9696d3a1acb036d65909d93d73455b8aed3a (patch)
tree9e8bb6797b3bebd0bf83ae1fab2151a6dfeafe6a /ubi-utils/src/nandecc.c
parentef644090223e5983ca2492850354c1390e3368d1 (diff)
Revert ubi-tools changes
Restore ubi tools to their "original" state, which means to the state they were before I stareted cleaning them up. Instead, create a "new-utils" subdirectory and move my work there. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'ubi-utils/src/nandecc.c')
-rw-r--r--ubi-utils/src/nandecc.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/ubi-utils/src/nandecc.c b/ubi-utils/src/nandecc.c
new file mode 100644
index 0000000..71660ef
--- /dev/null
+++ b/ubi-utils/src/nandecc.c
@@ -0,0 +1,159 @@
+/*
+ * This file contains an ECC algorithm from Toshiba that detects and
+ * corrects 1 bit errors in a 256 byte block of data.
+ *
+ * drivers/mtd/nand/nand_ecc.c
+ *
+ * Copyright (C) 2000-2004 Steven J. Hill (sjhill@realitydiluted.com)
+ * Toshiba America Electronics Components, Inc.
+ *
+ * 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
+ * Free Software Foundation; either version 2 or (at your option) any
+ * later version.
+ *
+ * This file 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 file; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * As a special exception, if other files instantiate templates or use
+ * macros or inline functions from these files, or you compile these
+ * files and link them with other works to produce a work based on these
+ * files, these files do not by themselves cause the resulting work to be
+ * covered by the GNU General Public License. However the source code for
+ * these files must still be made available in accordance with section (3)
+ * of the GNU General Public License.
+ *
+ * This exception does not invalidate any other reasons why a work based on
+ * this file might be covered by the GNU General Public License.
+ */
+
+#include "nandecc.h"
+
+/*
+ * Pre-calculated 256-way 1 byte column parity
+ */
+static const uint8_t nand_ecc_precalc_table[] = {
+ 0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a,
+ 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
+ 0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f,
+ 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
+ 0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c,
+ 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
+ 0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59,
+ 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
+ 0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33,
+ 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
+ 0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56,
+ 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
+ 0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55,
+ 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
+ 0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30,
+ 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
+ 0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30,
+ 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
+ 0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55,
+ 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
+ 0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56,
+ 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
+ 0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33,
+ 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
+ 0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59,
+ 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
+ 0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c,
+ 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
+ 0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f,
+ 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
+ 0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a,
+ 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00
+};
+
+/**
+ * nand_trans_result - [GENERIC] create non-inverted ECC
+ * @reg2: line parity reg 2
+ * @reg3: line parity reg 3
+ * @ecc_code: ecc
+ *
+ * Creates non-inverted ECC code from line parity
+ */
+static void nand_trans_result(uint8_t reg2, uint8_t reg3,
+ uint8_t *ecc_code)
+{
+ uint8_t a, b, i, tmp1, tmp2;
+
+ /* Initialize variables */
+ a = b = 0x80;
+ tmp1 = tmp2 = 0;
+
+ /* Calculate first ECC byte */
+ for (i = 0; i < 4; i++) {
+ if (reg3 & a) /* LP15,13,11,9 --> ecc_code[0] */
+ tmp1 |= b;
+ b >>= 1;
+ if (reg2 & a) /* LP14,12,10,8 --> ecc_code[0] */
+ tmp1 |= b;
+ b >>= 1;
+ a >>= 1;
+ }
+
+ /* Calculate second ECC byte */
+ b = 0x80;
+ for (i = 0; i < 4; i++) {
+ if (reg3 & a) /* LP7,5,3,1 --> ecc_code[1] */
+ tmp2 |= b;
+ b >>= 1;
+ if (reg2 & a) /* LP6,4,2,0 --> ecc_code[1] */
+ tmp2 |= b;
+ b >>= 1;
+ a >>= 1;
+ }
+
+ /* Store two of the ECC bytes */
+ ecc_code[1] = tmp1;
+ ecc_code[0] = tmp2;
+}
+
+/**
+ * nand_calculate_ecc - [NAND Interface] Calculate 3 byte ECC code for
+ * 256 byte block
+ *
+ * @dat: raw data
+ * @ecc_code: buffer for ECC
+ */
+int nand_calculate_ecc(const uint8_t *dat, uint8_t *ecc_code)
+{
+ uint8_t idx, reg1, reg2, reg3;
+ int j;
+
+ /* Initialize variables */
+ reg1 = reg2 = reg3 = 0;
+ ecc_code[0] = ecc_code[1] = ecc_code[2] = 0;
+
+ /* Build up column parity */
+ for(j = 0; j < 256; j++) {
+
+ /* Get CP0 - CP5 from table */
+ idx = nand_ecc_precalc_table[dat[j]];
+ reg1 ^= (idx & 0x3f);
+
+ /* All bit XOR = 1 ? */
+ if (idx & 0x40) {
+ reg3 ^= (uint8_t) j;
+ reg2 ^= ~((uint8_t) j);
+ }
+ }
+
+ /* Create non-inverted ECC code from line parity */
+ nand_trans_result(reg2, reg3, ecc_code);
+
+ /* Calculate final ECC code */
+ ecc_code[0] = ~ecc_code[0];
+ ecc_code[1] = ~ecc_code[1];
+ ecc_code[2] = ((~reg1) << 2) | 0x03;
+ return 0;
+}