DM355 EVM supports Big Block NAND up to 2GB, both MLC and SLC technologies. The production boards have 2GB SLC NAND chip - MT29F16G08FAA, with a block size of 128KB. The 2GB MLC NAND chip - MT29F16G08QAA, has a block size of 256KB. Both the NAND chips have a page size of 2K. There are two chip selects required to program the NAND space (1GB each), thus the NAND driver in U-Boot and Kernel treat the NAND chip as two NAND devices. A bad block table is maintained by the U-Boot, in the last two blocks of each NAND device (for each 1GB space). When U-Boot comes up for the first time on a new NAND device, it scans through the NAND space to identify bad blocks and creates the bad block table. This bad block table is consulted by both U-Boot and Kernel on any writes to the NAND space. The Initial 16 blocks are allocated for the bootloader components - UBL, U-Boot and Environment space. Block 1 through 7 : UBL descriptor and UBL Block 8 through 9 : U-Boot descriptor Block 10 through 14 : U-Boot Block 15 : U-boot Environment variables Note that extra blocks are allocated for the UBL and U-Boot to make sure there is at least one good block available for the corresponding descriptor and binary.
For 2GB SLC NAND chip (MT29F16G08FAA): tftp 0x80700000 u-boot-1.2.0-dm355_evm.bin nand erase 0x140000 0x20000 nand write 0x80700000 0x140000 0x20000 For 2GB MLC NAND chip (MT29F16G08QAA): tftp 0x80700000 u-boot-1.2.0-dm355_evm.bin nand erase 0x280000 0x20000 nand write 0x80700000 0x280000 0x20000
"bootloader": block 0 - block 14 "params": block 15 "kernel": 4MB starting block 16 "filesystem1": 512MB for the reduced filesystem (busybox based) "filesystem2": Remaining ~1.45GB, could be used for the MV target filesystem The "filesystem1" partition has been created to use a reduced filesystem. There is a known issue with YAFFS2 mount time. If a single filesystem with complete MV target filesystem, on each reboot it could take up to 15 mins to complete the mount process. (ken_yjj) |