gdisofs is a FUSE module you can use to explore the files in an image of a dreamcast game. It mounts the image as a read-only filesystem so you can browse through its contents and open files with whatever programs you want.
Initially I developped this way back in january 2017, during the early days of WashingtonDC. I don't remember exactly why I created it, but after that i didn't really need it for seven years. Then in January 2024 I found myself once again needing to check out some files on-disc so I dug this old girl up, fixed some bugs and added support for loading MIL-CD homebrews from .cdi images.
Currently it can only mount the filesystem as read-only, so you won't be able to make changes. I occasionally daydream about how cool it would be to be able to mod dreamcast games just by mucking about with files in gdisofs so I might implement rw-mode someday.
gdisofs is a fork of another project called 'fuseiso' which is a general-purpose ISO-9660fs implementation for FUSE; see AUTHORS for more information on its original creators. gdisofs is licensed under the terms of the GNU GPL version 2; see COPYING for terms and conditions.
usage is simple:
gdisofs <path-to-disc.gdi_OR_path-to-cdi> <mount-point>
for .gdi images, you'll provide the path to the .gdi file itself, not the directory. For .cdi images, you just provide the path to the cdi.
since it's just a FUSE module, this is done through fuse's fusermount command:
fusermount -u <path-to-mount-point>