Cobb Accessport Reverse Engineering
The flash chip is a Micron 2Gb NAND Flash 29F2G08ABAEA. The configuration as detected by my reader is as follows:
NAND ID: 0x2cda9095_0x6000000 Manufacturer: Micron *Page data area size 2048 bytes. *Page spare area size 64 bytes. *Each block has 64 pages *The chip has 1 chip-select signals. *There are 2048 blocks each chip-select. *Total 2048 blocks each chip. *Total memory size 256 Mbytes *Range 0x0 - 0xfffffff *Memory type: SLC NAND
I extracted the image from the flash chip using a "ProMan HS 057A" Chinese flash reader, with the "full info" option. After extraction I ran the image through imx-nand-convert with the -c option to error correct the image and then remove the "spare bytes" area that the physical flash uses.After extracting and scanning the flash image, I found a NXP Flash Configuration Block header that contained this data:
m_u32Checksum = FFFFFB37 _u32FingerPrint = 46434220 _u32Version = 0001 _NANDTiming = 06193C50 _u32PageDataSize = 0800 _u32TotalPageSize = 0840 _u32SectorsPerBlock = 0040 _u32NumberOfNANDs = 0000 _u32TotalInternalDie = 0000 _u32CellType = 0000 _u32EccBlockNEccType = BCH8 _u32EccBlock0Size = 0200 _u32EccBlockNSize = 0200 _u32EccBlock0EccType = BCH8 _u32MetadataBytes = 000A _u32NumEccBlocksPerPage = 0003 _u32EccBlockNEccLevelSDK = 0000 _u32EccBlock0SizeSDK = 0000 _u32EccBlockNSizeSDK = 0000 _u32EccBlock0EccLevelSDK = 0000 _u32NumEccBlocksPerPageSDK = 0000 _u32MetadataBytesSDK = 0000 _EraseThreshold = 0000 _BootPatch = 0000 _PatchSectors = 0000 _Firmware1_StartingSector = 0200 _Firmware2_StartingSector = 1500 _SectorsInFirmware1 = 07C2 _SectorsInFirmware2 = 07C2 _DBBTSearchAreaStartAddress = 0100 _BadBlockMarkerByte = 07CF _BadBlockMarkerStartBit = 0000 _BBMarkerPhysicalOffset = 0800Also in the image was what looks like a SbFileFormat header for the boot firmware based on the "STMP" magic I found. I didn't look much further into this.
The rest of the flash is occupied by an UBI-based volume manager with four filesystems contained within it.
|Prev: Hardware||Next: Filesystems|