US E-reader save format

Base Address = 0x00000 (Bank 0, address 0x0000)

Offset  Size		Description
0x0000	0x6FFC	    Bank 0 continuation of save data.
0x6FFD  0x6004      All 0xFF
0xD000	0x0053		43617264 2D452052 65616465 72203230
			30310000 67B72B2E 32333333 2F282D2E
			31323332 302B2B30 31323433 322F2A2C
			30333333 312F282C 30333233 3230292D
			30303131 2F2D2320 61050000 80FD7700
			000001
0xD053	0x0FAD		All 0x00s
0xE000	0x1000    Repeat 0xD000-0xDFFF
0xF000	0x0F80		All 0xFFs
0xFF80	0x0080		All 0x00s


Base Address = 0x10000 (Bank 1, address 0x0000)

Offset	Size		Description
0x0000	0x04		CRC (calculated starting from 0x0004,  and amount of data to calculate is
                      0x30 + [0x002C] + [0x0030].)
0x0004	0x24		Program Title (Null terminated) - US = Straight Ascii,  Jap = Shift JIS
0x0028	0x04		Program Type
				0x0204 = ARM/THUMB Code/data (able to use the GBA hardware directly, Linked to 0x02000000)
				0x0C05 = 6502 code/data (NES limitations, 1 16K program rom + 1-2 8K CHR rom, mapper 0 and 1)
				0x0400 = Z80 code/data (Linked to 0x0100)
0x002C	0x04		Program Size
				= First 2 bytes of Program data, + 2
0x0030	0x04		Unknown
0x0034	Program Size	Program Data (vpk compressed)
				First 2 bytes = Size of vpk compressed data
0xEFFF	0x01		End of save area in bank 1. Resume save data in bank 0.
				

The CRC is calculated on Beginning of Program Title, to End of Program Data.
If the First byte of Program Title is 0xFF, then there is no save present.
If the CRC calculation does not match stored CRC, then the ereader comes up with
an ereader memory error.

CRC calculation Details

CRC table is calculated from polynomial 0x04C11DB7 (standard CRC32 polynomial)
with Reflection In.  (Table entry 0 is 0, and 1 is 0x77073096...)

CRC calculation routine uses Initial value of 0xAA478422.  The Calculation routine
is not a standard CRC32 routine, but a custom made one, Look in "crc calc.c" for
the complete calculation algorithm.


Revision history

v1.0 - First release
V1.1 - Updated/Corrected info about program type.
v1.2 - Updated info on Japanese text encoding
v1.3 - Info on large 60K+ vpk files.