Hello,
I have hardly any knowledge on ARM assembler but I tried to click around a bit in IDA. This is what I figured out:
When searching through the dump I found the following ASCII data
ROM:FFAF2EC2 aPutinndfilter DCB "PutInNdFilter",0 ; DATA XREF: ROM:FFB00090
ROM:FFAF2ED0 aPutoutndfilter DCB "PutOutNdFilter",0 ; DATA XREF: ROM:FFB00088
When I followed the XREF I came to functions which looked similar to the ND functions in the VxWorks A710 firmware where ND Filter settings seem to be present.
Substituting in
platform/ixus860_sd870/sub/100c/stubs_entry_2.SNSTUB(PutInNdFilter, 0xFF810958)
NSTUB(PutOutNdFilter, 0xFF810958)
(which currently points to nullsub behaviour) with
NSTUB(PutInNdFilter, 0xFF9E448C)
NSTUB(PutOutNdFilter, 0xFF9E44C4)
seems to make some ND Filter setting working.
I changed "Extra Photo Operations->ND filter state". With ND Filter "in" the picture was significantly darker. This is what I expected from ND Filter. With "out" is was light as usual.
Unfortunately I could not find an clue about the setting in the EXIF data of the pictures (even after running "Auto CHDK to EXIF v1.2.exe").
Can anyone check this behaviour? How are ND Filter settings handled for the other cameras? Is there any EXIF marker?
Regards,
Chris