| /* |
| * Calculate Error-correcting Codes. Used by NAND Flash controllers |
| * (not by NAND chips). |
| * |
| * Copyright (c) 2006 Openedhand Ltd. |
| * Written by Andrzej Zaborowski <balrog@zabor.org> |
| * |
| * This code is licensed under the GNU GPL v2. |
| * |
| * Contributions after 2012-01-13 are licensed under the terms of the |
| * GNU GPL, version 2 or (at your option) any later version. |
| */ |
| |
| #include "hw/hw.h" |
| #include "hw/flash.h" |
| |
| /* |
| * Pre-calculated 256-way 1 byte column parity. Table borrowed from Linux. |
| */ |
| 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, |
| }; |
| |
| /* Update ECC parity count. */ |
| uint8_t ecc_digest(ECCState *s, uint8_t sample) |
| { |
| uint8_t idx = nand_ecc_precalc_table[sample]; |
| |
| s->cp ^= idx & 0x3f; |
| if (idx & 0x40) { |
| s->lp[0] ^= ~s->count; |
| s->lp[1] ^= s->count; |
| } |
| s->count ++; |
| |
| return sample; |
| } |
| |
| /* Reinitialise the counters. */ |
| void ecc_reset(ECCState *s) |
| { |
| s->lp[0] = 0x0000; |
| s->lp[1] = 0x0000; |
| s->cp = 0x00; |
| s->count = 0; |
| } |
| |
| /* Save/restore */ |
| VMStateDescription vmstate_ecc_state = { |
| .name = "ecc-state", |
| .version_id = 0, |
| .minimum_version_id = 0, |
| .minimum_version_id_old = 0, |
| .fields = (VMStateField []) { |
| VMSTATE_UINT8(cp, ECCState), |
| VMSTATE_UINT16_ARRAY(lp, ECCState, 2), |
| VMSTATE_UINT16(count, ECCState), |
| VMSTATE_END_OF_LIST(), |
| }, |
| }; |