I think I understand "ignore toc" already, but didn't know about the first, so I looked around online a little and then realized GCRebuilder has a readme. Inside, it says this:
Code:
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"Options" menu commands:
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// Note - this options only works BEFORE opening an extracted image (ROOT -> Open)
// When a usual GC image (Image -> Open) is opened, these options are disabled.
Options -> Modify system files
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- Modifies "iso.hdr" and "game.toc" files in "&&systemdata" folder while building a new image.
Use this option if you want these files to be identical in the "Root" folder and your new image.
Options -> Do not use 'game.toc'
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- With this option enabled, GCR ignores information from "game.toc" file.
It means that you can theorically build a new working GC image with ANY files in "Root" folder
(the "&&systemdata" folder must not contain additional files or folders).
The only limitation - is the file size of your new image.
It should be exactly 1.35 Gb (1459978240 bytes).
All you'll need - is a correct "apploader.ldr" and "start.dol" files in "&&systemdata" folder
to make such image work.
// Use this options only IF YOU REALLY KNOW, what you are doing!!!
// If you don't sure - than just left them disabled.
I think that the only thing that GCRebuilder uses the file system table (FST) in Game.toc for is to know what files to choose within the selected folder when building an ISO, which is why Game.toc needs to be ignored when building an ISO with new files. A brand new FST is then written into your new ISO, probably regardless of whether the option is on or not (to ensure it has the correct file sizes). If you have "extra" files going into your ISO, I think the only other thing in the ISO that needs to be updated is a value for the size of the FST, listed in the .hdr file (which must be an abbreviation of "header", I figure), which would be different if you have a different number of files from the original disc.This value might also be re-evaluated (rather than just copied from the original .hdr) regardless of the options selected in GCRebuilder.
It looks like 'Modify System Files' then just updates the files in your
extracted files directory, and doesn't actually affect the new game's construction. It's just so that your "source files" match the new ISO you're making, so you don't have to re-extract them.