8G CF card support

[dzh]

windows7 ultimate
win32 disk imager 2.0
I try to backup a 8Gb CF card using USB card reader , but only got a 4G file.

[Jeff L (jll544)]

Current read/write functions calculate 64-bit file addresses but pass only 32-bits to SetFilePointer(), resulting in wrap-around of any image/device larger than 4GB. Attached patch addresses this issue.

[Neil Mayhew (neil.mayhew)]

This problem should have produced an error message but didn't, which caused me to waste a lot of time trying to figure out why the 8GB cards I had created didn't work. The reason it didn't produce an error is that the return status from SetFilePointer isn't checked like it should be.

This patch adds these checks in addition to using 64-bit file offsets as Jeff L's patch does. Also, it uses SetFilePointerEx which is a slightly neater way to handle 64-bit offsets.

Is there any chance this fix could be merged and a new release made? I am recommending this utility to my users but I'd much rather they got an official released copy instead of getting a patched one from me.

[Kent Dalton (kent-dalton)]

PLEASE will someone recompile this and make it available? Is this tool abandonware?

[Tobin Davis (gruemaster)]

Currently, I am reviewing 3 different patches for this issue, but I am not able to get predictable results. My testing method is to fill an 8G SD with random data (sudo dd bs=4M if=/dev/random of=/dev/mmcblk0) and then read that in in both linux and win32-image-writer and compare the reads with md5sum. This is proving to take a very long time and not providing me with consistent results. I will push out v0.4 without this fix if I can not resolve this by Jan 2, 2012.