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Wiki > Main > SansaE200FirmwarePartition (compare)

Difference: SansaE200FirmwarePartition (r5 vs. r4)

SanDisk Sansa E200 Firmware Partition

Description

The SanDisk Sansa e200 series has a 20MB hidden firmware partition. It holds both the bootloader and main firmware. This partition is either not present or hidden by e200r firmwares.

The partition is 20MB and is at the end of the disk. It doesn't have any partition table, but has files at specific address locations inside it. Each file has a 512B (1 sector) header which has a 4 character string describing its contents, followed by a 32-bit little endian number indicating the length of the file in bytes. There is then a 32 bit number with an unknown purpose.

Structure

Addresses are relative to the start of the partition. The partition is divided up into 3 block. The first block is 512KB for the bootloader. The last 5MB of the partition is for the ppfn (image?) data. The remaining space in between is used for the main firmware.

AddressDescription
0x0 Bootloader header - PPBL followed by the bootloader length, followed by 0x10000
0x200 Bootloader
0x80000 Main firmware header - PPMI followed by firmware length, followed by 0x20000
0x80200 Main firmware in mi4 format
0x780000 NVPARAMS
0x780200 PPPS Non-volatile parameters - used by the OF to save data (eg. current track, database status, etc.) through a power cycle. There appears to be a header here too
0x7810e4 0x7810e1 Database rebuild in firmware version 1.01.11A. If this is set to 1, the database is rebuilt on next reboot
0x78b808 0x800000 Database rebuild in firmware version Unknown data of length 0x200 1.00.12E. If this is set to 1, the database is rebuilt on next reboot
0xefe400 PPID followed by length (0x10), followed by 0x40000
0xefe600 ppid data. Unknown purpose. Reads DF 83 75 C6 F6 FC 1A 44 84 66 45 99 6C E1 DC 70 on Sansa e280
0xf00000 PPFN followed by length followed by 0x30000
0xf00000 ppfn data. Possibly images or animation used by the bootloader

r7 - 22 Oct 2007 - 17:22:20 - BertrikSikken

Revision r5 - 20 Oct 2007 - 15:02 - BarryWardell
Revision r4 - 21 Aug 2007 - 19:45 - SamuelKatz
Copyright by the contributing authors.