And even attempting to "make all" for opl2iso separately is still doomed to fail if one does not first edit the "opl2iso.c" file to insert the directive "#define _WIN32 1", as I also described in our discussion elsewhere.
Unfortunately that still applies even to rev 332 of the GUI branch of OPL, released after I made my posts on this with the suggested changes attached, in that other forum.
The current iso2opl and opl2iso sources rely on that macro for knowing when a compile is to generate code for a Windows OS, even though that is a standard macro specific for "Visual Studio" and not at all implemented in our Cygwin setups (probably not in MinGW/MSYS either).
After such editing to insert that macro definition opl2iso will compile well, but iso2opl is still doomed to failure in a Cygwin environment where the standard libs linked do not include the two functions "fseeko64" and "ftello64". So to compile at least opl2iso, this will have to be done separately, using not "make pc_tools" in the main OPL folder but instead going inside the opl2iso folder and using the command "make all" for it alone.
There are quite a lot of such games, and it would be a definite advantage to be able to move them between USB drives without having to use special installer programs like USBUtil. Not least when using the simplest and idiot-proof defragmenting method.Finally, I forgot to mention in the commit, that ISO support is only for SMB (maybe it could be added to USB, for games < 2Go, mainly CD games ...).
By that I mean the method where you copy all content from USB stick to HDD, reformat USB stick, and then copy all the stuff back to USB stick again. Doing that through a real re-install for each game in USBA format would waste tons of time, compared to simple ISO file copying.
In any case, lack of USB ISO support at present explains why my experiments last night gave no useful result for the USB drive. At the time I thought it could be because I had eliminated all the games installed by USBA methods, and thus had no "ul.cfg" file on that drive, causing it to be overlooked by OPL just for that reason. But that guess was evidently wrong.
I really think ISO support should be added for the USB core as well, considering the fairly large amount of games out there of less than 2 GiB, and those also being the most likely 'targets' for someone composing a game collection on USB sticks.
Best regards: dlanor