It can be 2, 4, 8, 12 or 24.
2. The PMECC sector size: CONFIG_PMECC_SECTOR_SIZE.
It only can be 512 or 1024.
- 3. The PMECC index lookup table's offsets in ROM code: CONFIG_PMECC_INDEX_TABLE_OFFSET.
- In the chip datasheet section "Boot Stragegies", you can find
- two Galois Field Table in the ROM code. One table is for 512-bytes
- sector. Another is for 1024-byte sector. Each Galois Field includes
- two sub-table: indext table & alpha table.
- In the beginning of each Galois Field Table is the index table,
- Alpha table is in the following.
- So the index table's offset is same as the Galois Field Table.
-
- Please set CONFIG_PMECC_INDEX_TABLE_OFFSET correctly according the
- Galois Field Table's offset base on the sector size you used.
-
-Take AT91SAM9X5EK as an example, the board definition file likes:
-
-/* PMECC & PMERRLOC */
-#define CONFIG_ATMEL_NAND_HWECC 1
-#define CONFIG_ATMEL_NAND_HW_PMECC 1
-#define CONFIG_PMECC_CAP 2
-#define CONFIG_PMECC_SECTOR_SIZE 512
-#define CONFIG_PMECC_INDEX_TABLE_OFFSET 0x8000
-
-NOTE: If you use 1024 as the sector size, then need set 0x10000 as the
- CONFIG_PMECC_INDEX_TABLE_OFFSET
+
+Take 'configs/at91sam9x5ek_nandflash_defconfig' as an example, the board
+configuration file has the following entries:
+
+ CONFIG_PMECC_CAP=2
+ CONFIG_PMECC_SECTOR_SIZE=512
+ CONFIG_SPL_GENERATE_ATMEL_PMECC_HEADER=y
+
+How to enable PMECC header for direct programmable boot.bin
+-----------------------------------------------------------
+
+The usual way to program SPL into NAND flash is to use the SAM-BA Atmel tool.
+This however is often not usable when doing field updates. To be able to
+program a SPL binary into NAND flash we need to add the PMECC header to the
+binary before. Chapter '12.4.4.1 NAND Flash Boot: NAND Flash Detection' in
+sama5d3 SoC spec (as of 03. April 2014) defines how this PMECC header has to
+look like. In order to do so we have a new image type added to mkimage to
+generate this PMECC header and integrated this into the build process of SPL.
+
+To enable the generation of atmel PMECC header for SPL one needs to define
+CONFIG_SPL_GENERATE_ATMEL_PMECC_HEADER. The required parameters are taken from
+board configuration and compiled into the host tools atmel_pmecc_params. This
+tool will be called in build process to parametrize mkimage for atmelimage
+type. The mkimage tool has intentionally _not_ compiled in those parameters.
+
+The mkimage image type atmelimage also set the 6'th interrupt vector to the
+correct value. This feature can also be used to setup a boot.bin for MMC boot.