Calculating the ECC strength dynamically to be aligned with the mxs NAND driver and the Linux Kernel.
The macro definition for round_down is taken from <linux/kernel.h> to avoid changing the tools/Makefile where the Linux Kernel header files are not included for building the tools target.
Signed-off-by: Jörg Krause joerg.krause@embedded.rocks --- tools/mxsboot.c | 36 ++++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/tools/mxsboot.c b/tools/mxsboot.c index aaa872b..8fca8cf 100644 --- a/tools/mxsboot.c +++ b/tools/mxsboot.c @@ -14,6 +14,10 @@
#include "compiler.h"
+/* Taken from <linux/kernel.h> */ +#define __round_mask(x, y) ((__typeof__(x))((y)-1)) +#define round_down(x, y) ((x) & ~__round_mask(x, y)) + /* * Default BCB layout. * @@ -126,6 +130,11 @@ struct mx28_sd_config_block { struct mx28_sd_drive_info drv_info[1]; };
+static inline uint32_t mx28_nand_ecc_chunk_cnt(uint32_t page_data_size) +{ + return page_data_size / MXS_NAND_CHUNK_DATA_CHUNK_SIZE; +} + static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength) { return ecc_strength * MXS_NAND_BITS_PER_ECC_LEVEL; @@ -134,21 +143,20 @@ static inline uint32_t mx28_nand_ecc_size_in_bits(uint32_t ecc_strength) static inline uint32_t mx28_nand_get_ecc_strength(uint32_t page_data_size, uint32_t page_oob_size) { - if (page_data_size == 2048) - return 8; - - if (page_data_size == 4096) { - if (page_oob_size == 128) - return 8; - - if (page_oob_size == 218) - return 16; - - if (page_oob_size == 224) - return 16; - } + int ecc_strength; + + /* Determine the ECC layout with the formula: + * ECC bits per chunk = (total page spare data bits) / + * (bits per ECC level) / (chunks per page) + * where: + * total page spare data bits = + * (page oob size - meta data size) * (bits per byte) + */ + ecc_strength = ((page_oob_size - MXS_NAND_METADATA_SIZE) * 8) + / (MXS_NAND_BITS_PER_ECC_LEVEL * + mx28_nand_ecc_chunk_cnt(page_data_size));
- return 0; + return round_down(ecc_strength, 2); }
static inline uint32_t mx28_nand_get_mark_offset(uint32_t page_data_size,