This page is obsolete. Please head to: for information on the latest hack of 400d.Edit

This page contains information that is eventually meant to result in a CHDK port for the 400D / Rebel XTi.

Firmware info Edit

Version Edit

Latest Version v1.1.1
Firmware can be updated by end user and downloaded from Canon website.
Firmware can be decrypted with the same utility that works for the Canon 30D.,134.msg2461.html#msg2461
firmware is loaded at 0xFF810000

Firmware contentEdit

Fir_tool 0.5 for 5D/30D/400D (9May2010)

fileLen = 0x4aad50
---.fir header---
0x000: modelId = 0x80000236, (400D / Rebel XTi, VxWorks)
0x010: version = 1.1.0
---ciphered part (xor)---
xor_decoding [0x20-0x4aad50]... OK (0236_110_firmware.bin)
0x020: checksum = 0xe365a664
checksum computing [0x0-0x4aad50] is OK!
0x024: updater offset = 0x30
0x028: firmware pack offset = 0x127c90
0x02c: = 0x0
0x030: ---updater---
0x127c90: ---firmware---
0x127c90: (+0x000) firmware checksum = 0xea620eaa
checksum computing [0x127c94-0x4aad50] is OK!
0x127c94: number of files in the pack = 13
0x127c98: offset to the file table = 0x18 (from 0x127c90)
0x127c9c: header size = 0x220 (from 0x127c90). end of header = 0x127eb0
0x127ca0: size of file table = 0x208
0x127ca4: size after table = 0x382ea0
0x127c88: (+0x018) files table
0x127ca8: 0x0008 0x000220 0x01b040 BIND_RESOURCE
0x127cd0: 0x0003 0x01b260 0x3594f0 MAIN_FIRMWARE
0x127cf8: 0x0004 0x374750 0x000004 ModelID
0x127d20: 0x0004 0x374754 0x000005 FirmwareVersion
0x127d48: 0x0004 0x374759 0x00000a ICUVersion
0x127d70: 0x0004 0x374763 0x0001f8 FileSizeTable
0x127d98: 0x0004 0x37495b 0x001aff LensNameTbl
0x127dc0: 0x0004 0x37645a 0x000094 LensPOTbl
0x127de8: 0x0004 0x3764ee 0x000f2c AdjWbFix
0x127e10: 0x0004 0x37741a 0x00469a CrwParam
0x127e38: 0x0004 0x37bab4 0x00722c FlavorLutParam
0x127e60: 0x0004 0x382ce0 0x000218 ColorAdjustDefaultAngel
0x127e88: 0x000b 0x382ef8 0x0001c8 EEP
0x127eb0: (+0x220) end of table, first file

Hardware info Edit

DIGIC II, ARM946ES VxWorks 5.5.1 EOS 400D already provides many of the CHDK features.

Firmware Hack Info Edit

A hacked firmware is developed (in the forum) :,3290.0.html

Downloads Edit

400plus project on Google Code

Installation Edit

Please use updated information here:

Functionalities Edit

Please refer to the guide at:

Credits Edit

(Apologies for mistakes)

Big thanks goes to:
for the initial work: Owerlord, Seklth, Thaibv & Foldesa from CHDK Forum
for the current project: EduPerez, Sergei, 0xAF
Installation : raingrove, thaibv, 0xAF
Community content is available under CC-BY-SA unless otherwise noted.