Git Repo - qemu.git/blame_incremental

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Commit	Line	Data
	1	/*
	2	* Calculate Error-correcting Codes. Used by NAND Flash controllers
	3	* (not by NAND chips).
	4	*
	5	* Copyright (c) 2006 Openedhand Ltd.
	6	* Written by Andrzej Zaborowski <[email protected]>
	7	*
	8	* This code is licensed under the GNU GPL v2.
	9	*/
	10
	11	#include "hw.h"
	12	#include "flash.h"
	13
	14	/*
	15	* Pre-calculated 256-way 1 byte column parity. Table borrowed from Linux.
	16	*/
	17	static const uint8_t nand_ecc_precalc_table[] = {
	18	0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a,
	19	0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
	20	0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f,
	21	0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
	22	0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c,
	23	0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
	24	0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59,
	25	0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
	26	0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33,
	27	0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
	28	0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56,
	29	0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
	30	0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55,
	31	0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
	32	0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30,
	33	0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
	34	0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30,
	35	0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
	36	0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55,
	37	0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
	38	0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56,
	39	0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
	40	0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33,
	41	0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
	42	0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59,
	43	0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
	44	0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c,
	45	0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
	46	0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f,
	47	0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
	48	0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a,
	49	0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
	50	};
	51
	52	/* Update ECC parity count. */
	53	uint8_t ecc_digest(ECCState *s, uint8_t sample)
	54	{
	55	uint8_t idx = nand_ecc_precalc_table[sample];
	56
	57	s->cp ^= idx & 0x3f;
	58	if (idx & 0x40) {
	59	s->lp[0] ^= ~s->count;
	60	s->lp[1] ^= s->count;
	61	}
	62	s->count ++;
	63
	64	return sample;
	65	}
	66
	67	/* Reinitialise the counters. */
	68	void ecc_reset(ECCState *s)
	69	{
	70	s->lp[0] = 0x0000;
	71	s->lp[1] = 0x0000;
	72	s->cp = 0x00;
	73	s->count = 0;
	74	}
	75
	76	/* Save/restore */
	77	void ecc_put(QEMUFile f, ECCState s)
	78	{
	79	qemu_put_8s(f, &s->cp);
	80	qemu_put_be16s(f, &s->lp[0]);
	81	qemu_put_be16s(f, &s->lp[1]);
	82	qemu_put_be16s(f, &s->count);
	83	}
	84
	85	void ecc_get(QEMUFile f, ECCState s)
	86	{
	87	qemu_get_8s(f, &s->cp);
	88	qemu_get_be16s(f, &s->lp[0]);
	89	qemu_get_be16s(f, &s->lp[1]);
	90	qemu_get_be16s(f, &s->count);
	91	}