mirror of
https://github.com/eclipse-threadx/levelx.git
synced 2026-09-14 12:37:01 +08:00
228 lines
9.0 KiB
C
228 lines
9.0 KiB
C
/***************************************************************************
|
|
* Copyright (c) 2024 Microsoft Corporation
|
|
* Copyright (c) 2026-present Eclipse ThreadX contributors
|
|
*
|
|
* This program and the accompanying materials are made available under the
|
|
* terms of the MIT License which is available at
|
|
* https://opensource.org/licenses/MIT.
|
|
*
|
|
* SPDX-License-Identifier: MIT
|
|
**************************************************************************/
|
|
|
|
|
|
/**************************************************************************/
|
|
/**************************************************************************/
|
|
/** */
|
|
/** LevelX Component */
|
|
/** */
|
|
/** NAND Flash */
|
|
/** */
|
|
/**************************************************************************/
|
|
/**************************************************************************/
|
|
|
|
#define LX_SOURCE_CODE
|
|
|
|
|
|
/* Disable ThreadX error checking. */
|
|
|
|
#ifndef LX_DISABLE_ERROR_CHECKING
|
|
#define LX_DISABLE_ERROR_CHECKING
|
|
#endif
|
|
|
|
|
|
/* Include necessary system files. */
|
|
|
|
#include "lx_api.h"
|
|
|
|
|
|
/**************************************************************************/
|
|
/* */
|
|
/* FUNCTION RELEASE */
|
|
/* */
|
|
/* _lx_nand_flash_256byte_ecc_compute PORTABLE C */
|
|
/* 6.2.1 */
|
|
/* AUTHOR */
|
|
/* */
|
|
/* William E. Lamie, Microsoft Corporation */
|
|
/* */
|
|
/* DESCRIPTION */
|
|
/* */
|
|
/* This function computes the ECC for 256 bytes of a NAND flash page. */
|
|
/* The resulting ECC code is returned in 3 bytes. */
|
|
/* */
|
|
/* INPUT */
|
|
/* */
|
|
/* page_buffer Page buffer */
|
|
/* ecc_buffer Returned ECC buffer */
|
|
/* */
|
|
/* OUTPUT */
|
|
/* */
|
|
/* return status */
|
|
/* */
|
|
/* CALLS */
|
|
/* */
|
|
/* None */
|
|
/* */
|
|
/* CALLED BY */
|
|
/* */
|
|
/* _lx_nand_flash_page_ecc_compute NAND page ECC compute */
|
|
/* _lx_nand_flash_256byte_ecc_check Check 256 bytes and ECC */
|
|
/* */
|
|
/**************************************************************************/
|
|
UINT _lx_nand_flash_256byte_ecc_compute(UCHAR *page_buffer, UCHAR *ecc_buffer)
|
|
{
|
|
|
|
USHORT i, j;
|
|
USHORT *data;
|
|
USHORT bits, mask;
|
|
USHORT bit_parity;
|
|
USHORT even_bit_parity;
|
|
USHORT odd_bit_parity;
|
|
USHORT even_byte_parity;
|
|
USHORT odd_byte_parity;
|
|
|
|
|
|
/* Initialize local variables. */
|
|
bit_parity = 0;
|
|
even_bit_parity = 0;
|
|
odd_bit_parity = 0;
|
|
even_byte_parity = 0;
|
|
odd_byte_parity = 0;
|
|
|
|
/* Initialize the return ECC code area. */
|
|
ecc_buffer[0]= 0;
|
|
ecc_buffer[1]= 0;
|
|
ecc_buffer[2]= 0;
|
|
|
|
/* Setup a 16-bit pointer to the buffer area. */
|
|
data = (USHORT *) page_buffer;
|
|
|
|
/* Loop through the 256 byte buffer, 16 bits at a time. */
|
|
for (i = 0; i < 128; i++)
|
|
{
|
|
|
|
/* Compute the ECC value. */
|
|
bit_parity = bit_parity ^ data[i];
|
|
|
|
/* Now count the bits in the current data word. */
|
|
bits = 0;
|
|
mask = 1;
|
|
for (j = 0; j < 16; j++)
|
|
{
|
|
|
|
/* Is the bit set? */
|
|
if (data[i] & mask)
|
|
{
|
|
|
|
/* Yes, increment the bit count. */
|
|
bits++;
|
|
}
|
|
|
|
/* Move the mask to the next bit. */
|
|
mask = (USHORT) ((mask << 1) & 0xFFFF);
|
|
}
|
|
|
|
/* Determine if the number of bits is odd. */
|
|
if ((bits & 1) == 1)
|
|
{
|
|
|
|
/* Odd number of bits. Adjust the odd/even byte parity. */
|
|
even_byte_parity = (USHORT) ((even_byte_parity ^ (0xffff - i)) & 0xFFFF);
|
|
odd_byte_parity = odd_byte_parity ^ i;
|
|
}
|
|
}
|
|
|
|
/* Now look for bits set in the bit parity. */
|
|
for (i = 0; i < 16; i++)
|
|
{
|
|
|
|
/* Is the bit set? */
|
|
if (bit_parity & 1)
|
|
{
|
|
|
|
/* Yes, adjust the odd even byte parity. */
|
|
even_bit_parity = (USHORT) ((even_bit_parity ^ (15 - i)) & 0xFFFF);
|
|
odd_bit_parity = odd_bit_parity ^ i;
|
|
}
|
|
|
|
/* Look at next bit position. */
|
|
bit_parity = bit_parity >> 1;
|
|
}
|
|
|
|
/* At this point, we need to pack the 22 ECC bits into the 3 byte return area. */
|
|
|
|
/* Pack bit 21. */
|
|
ecc_buffer[(21+2)/8] = ((UCHAR)(ecc_buffer[(21+2)/8] | ((odd_byte_parity >> 6) & 1) << (21+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 20. */
|
|
ecc_buffer[(20+2)/8] = ((UCHAR)(ecc_buffer[(20+2)/8] | ((even_byte_parity >> 6) & 1) << (20+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 19. */
|
|
ecc_buffer[(19+2)/8] = ((UCHAR)(ecc_buffer[(19+2)/8] | ((odd_byte_parity >> 5) & 1) << (19+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 18. */
|
|
ecc_buffer[(18+2)/8] = ((UCHAR)(ecc_buffer[(18+2)/8] | ((even_byte_parity >> 5) & 1) << (18+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 17. */
|
|
ecc_buffer[(17+2)/8] = ((UCHAR)(ecc_buffer[(17+2)/8] | ((odd_byte_parity >> 4) & 1) << (17+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 16. */
|
|
ecc_buffer[(16+2)/8] = ((UCHAR)(ecc_buffer[(16+2)/8] | ((even_byte_parity >> 4) & 1) << (16+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 15. */
|
|
ecc_buffer[(15+2)/8] = ((UCHAR)(ecc_buffer[(15+2)/8] | ((odd_byte_parity >> 3) & 1) << (15+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 14. */
|
|
ecc_buffer[(14+2)/8] = ((UCHAR)(ecc_buffer[(14+2)/8] | ((even_byte_parity >> 3) & 1) << (14+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 13. */
|
|
ecc_buffer[(13+2)/8] = ((UCHAR)(ecc_buffer[(13+2)/8] | ((odd_byte_parity >> 2) & 1) << (13+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 12. */
|
|
ecc_buffer[(12+2)/8] = ((UCHAR)(ecc_buffer[(12+2)/8] | ((even_byte_parity >> 2) & 1) << (12+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 11. */
|
|
ecc_buffer[(11+2)/8] = ((UCHAR)(ecc_buffer[(11+2)/8] | ((odd_byte_parity >> 1) & 1) << (11+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 10. */
|
|
ecc_buffer[(10+2)/8] = ((UCHAR)(ecc_buffer[(10+2)/8] | ((even_byte_parity >> 1) & 1) << (10+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 9. */
|
|
ecc_buffer[(9+2)/8] = ((UCHAR)(ecc_buffer[(9+2)/8] | ((odd_byte_parity >> 0) & 1) << (9+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 8. */
|
|
ecc_buffer[(8+2)/8] = ((UCHAR)(ecc_buffer[(8+2)/8] | ((even_byte_parity >> 0) & 1) << (8+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 7. */
|
|
ecc_buffer[(7+2)/8] = ((UCHAR)(ecc_buffer[(7+2)/8] | ((odd_bit_parity >> 3) & 1) << (7+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 6. */
|
|
ecc_buffer[(6+2)/8] = ((UCHAR)(ecc_buffer[(6+2)/8] | ((even_bit_parity >> 3) & 1) << (6+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 5. */
|
|
ecc_buffer[(5+2)/8] = ((UCHAR)(ecc_buffer[(5+2)/8] | ((odd_bit_parity >> 2) & 1) << (5+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 4. */
|
|
ecc_buffer[(4+2)/8] = ((UCHAR)(ecc_buffer[(4+2)/8] | ((even_bit_parity >> 2) & 1) << (4+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 3. */
|
|
ecc_buffer[(3+2)/8] = ((UCHAR)(ecc_buffer[(3+2)/8] | ((odd_bit_parity >> 1) & 1) << (3+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 2. */
|
|
ecc_buffer[(2+2)/8] = ((UCHAR)(ecc_buffer[(2+2)/8] | ((even_bit_parity >> 1) & 1) << (2+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 1. */
|
|
ecc_buffer[(1+2)/8] = ((UCHAR)(ecc_buffer[(1+2)/8] | ((odd_bit_parity >> 0) & 1) << (1+2)%8) & 0xFF);
|
|
|
|
/* Pack bit 0. */
|
|
ecc_buffer[(0+2)/8] = ((UCHAR)(ecc_buffer[(0+2)/8] | ((even_bit_parity >> 0) & 1) << (0+2)%8) & 0xFF);
|
|
|
|
ecc_buffer[0] = (UCHAR)~ecc_buffer[0];
|
|
ecc_buffer[1] = (UCHAR)~ecc_buffer[1];
|
|
ecc_buffer[2] = (UCHAR)~ecc_buffer[2];
|
|
|
|
/* Return success! */
|
|
return(LX_SUCCESS);
|
|
}
|
|
|