Some games work in 3.00 but not in 3.02 - this is probably due to sony fixing bugs - for example BIA fails to load in 3.02 but works fine in 3.00 - that's strange wouldn't you say? well not really - simply by replacing sysmem.prx into 3.02 firmware it will work.....
There might be other games that need the same - by that I mean prx swapping, so I have drawn up a list of all the files that are different between firmware - this was done by decrypting both sets of firmware and doing a hex compare with some software I have on my pc.
Files that differ are:
Reboot.bin (don't swap)
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kd folder
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int.prx
lfatfs.prx
lflash_fatfmt.prx
libhttp.prx - (byte size)
loadcore.prx (don't swap this or firmware will crash)......
loadexec.prx
pspnet_adhoc_matching.prx - (byte size)
pspnet_apctl.prx - (byte size)
pspnet_inet.prx - (byte size)
sysmem.prx
umdman.prx - (byte size)
usbgps.prx - (byte size)
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vsh/etc folder
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index.dat - used for fimware id (don't swap)
version.txt - used for firmware id (don't swap)
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vsh/module folder
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htmlviewer_plugin.prx - (byte size)
htmlviewer_utility.prx
licence_plugin.prx
vshmain.prx
The obvious files, have byte size next to them - they are easy to see - however the files that don't have byte size next to them are not as they are the same amount of bytes in both firmware - however they do differ by a small amount - usually 1 byte is different, this is not the file version - as most files have that change, but a different byte - probably some protection bit or something.
what each of these prx's do, and which ones will proboblly affect a game:
flash0:/kd
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int.prx - (initiates games, may affect game)
lfatfs.prx - (shouldnt affect game, reads ms)
lflash_fatfmt.prx - (not used for devhook to run, wont affect games anyways)
libhttp.prx - (wont affect game - browser)
loadcore.prx - (may affect game, loads games)
loadexec.prx - (may affect game, loads games)
pspnet_adhoc_matching.prx - (wont affect game - browser)
pspnet_apctl.prx - (wont affect game - browser)
pspnet_inet.prx - (wont affect game - browser)
sysmem.prx - (affects game's)
umdman.prx - (may affect game)
usbgps.prx - (fix's gps bug, wont affect game)
none of the files in VSH will affect a game