X-Git-Url: http://www.aleph1.co.uk/gitweb/?p=yaffs2.git;a=blobdiff_plain;f=yaffs_ecc.c;h=0ea0305e5ceb10025f9e4016c439930631ac9a79;hp=4030908d518178c01de13b195290a3970337e627;hb=ddd1501c01e281d0a86424980ccdd1e4d7d16046;hpb=7396445d7d0d13469b9505791114b9dc6b76ffe4 diff --git a/yaffs_ecc.c b/yaffs_ecc.c index 4030908..0ea0305 100644 --- a/yaffs_ecc.c +++ b/yaffs_ecc.c @@ -106,7 +106,7 @@ void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc) b = column_parity_table[*data++]; col_parity ^= b; - if (b & 0x01) { /* odd number of bits in the byte */ + if (b & 0x01) { /* odd number of bits in the byte */ line_parity ^= i; line_parity_prime ^= ~i; } @@ -160,11 +160,10 @@ void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc) #endif } - /* Correct the ECC on a 256 byte block of data */ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, - const unsigned char *test_ecc) + const unsigned char *test_ecc) { unsigned char d0, d1, d2; /* deltas */ @@ -173,7 +172,7 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, d2 = read_ecc[2] ^ test_ecc[2]; if ((d0 | d1 | d2) == 0) - return 0; /* no error */ + return 0; /* no error */ if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 && ((d1 ^ (d1 >> 1)) & 0x55) == 0x55 && @@ -220,19 +219,18 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, data[byte] ^= (1 << bit); - return 1; /* Corrected the error */ + return 1; /* Corrected the error */ } if ((yaffs_count_bits(d0) + - yaffs_count_bits(d1) + - yaffs_count_bits(d2)) == 1) { + yaffs_count_bits(d1) + yaffs_count_bits(d2)) == 1) { /* Reccoverable error in ecc */ read_ecc[0] = test_ecc[0]; read_ecc[1] = test_ecc[1]; read_ecc[2] = test_ecc[2]; - return 1; /* Corrected the error */ + return 1; /* Corrected the error */ } /* Unrecoverable error */ @@ -241,12 +239,11 @@ int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc, } - /* * ECCxxxOther does ECC calcs on arbitrary n bytes of data */ void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes, - yaffs_ECCOther *eccOther) + struct yaffs_ecc_other *ecc_other) { unsigned int i; @@ -259,7 +256,7 @@ void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes, b = column_parity_table[*data++]; col_parity ^= b; - if (b & 0x01) { + if (b & 0x01) { /* odd number of bits in the byte */ line_parity ^= i; line_parity_prime ^= ~i; @@ -267,54 +264,56 @@ void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes, } - eccOther->colParity = (col_parity >> 2) & 0x3f; - eccOther->lineParity = line_parity; - eccOther->lineParityPrime = line_parity_prime; + ecc_other->col_parity = (col_parity >> 2) & 0x3f; + ecc_other->line_parity = line_parity; + ecc_other->line_parity_prime = line_parity_prime; } int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes, - yaffs_ECCOther *read_ecc, - const yaffs_ECCOther *test_ecc) + struct yaffs_ecc_other *read_ecc, + const struct yaffs_ecc_other *test_ecc) { - unsigned char cDelta; /* column parity delta */ - unsigned lDelta; /* line parity delta */ - unsigned lDeltaPrime; /* line parity delta */ + unsigned char delta_col; /* column parity delta */ + unsigned delta_line; /* line parity delta */ + unsigned delta_line_prime; /* line parity delta */ unsigned bit; - cDelta = read_ecc->colParity ^ test_ecc->colParity; - lDelta = read_ecc->lineParity ^ test_ecc->lineParity; - lDeltaPrime = read_ecc->lineParityPrime ^ test_ecc->lineParityPrime; + delta_col = read_ecc->col_parity ^ test_ecc->col_parity; + delta_line = read_ecc->line_parity ^ test_ecc->line_parity; + delta_line_prime = + read_ecc->line_parity_prime ^ test_ecc->line_parity_prime; - if ((cDelta | lDelta | lDeltaPrime) == 0) - return 0; /* no error */ + if ((delta_col | delta_line | delta_line_prime) == 0) + return 0; /* no error */ - if (lDelta == ~lDeltaPrime && - (((cDelta ^ (cDelta >> 1)) & 0x15) == 0x15)) { + if (delta_line == ~delta_line_prime && + (((delta_col ^ (delta_col >> 1)) & 0x15) == 0x15)) { /* Single bit (recoverable) error in data */ bit = 0; - if (cDelta & 0x20) + if (delta_col & 0x20) bit |= 0x04; - if (cDelta & 0x08) + if (delta_col & 0x08) bit |= 0x02; - if (cDelta & 0x02) + if (delta_col & 0x02) bit |= 0x01; - if (lDelta >= n_bytes) + if (delta_line >= n_bytes) return -1; - data[lDelta] ^= (1 << bit); + data[delta_line] ^= (1 << bit); - return 1; /* corrected */ + return 1; /* corrected */ } - if ((yaffs_count_bits32(lDelta) + yaffs_count_bits32(lDeltaPrime) + - yaffs_count_bits(cDelta)) == 1) { + if ((yaffs_count_bits32(delta_line) + + yaffs_count_bits32(delta_line_prime) + + yaffs_count_bits(delta_col)) == 1) { /* Reccoverable error in ecc */ *read_ecc = *test_ecc; - return 1; /* corrected */ + return 1; /* corrected */ } /* Unrecoverable error */