I, too, have been looking for a GB emulator recently. I downloaded both GNUBoy and VisiualBoyAdvance. I don't know how to run GNUBoy (typing gnuboy into the terminal doesn't work and I can't find it in the menus). VBA seems to have been installed properly, but I don't know where to find ROMs.
In terms of ROMS, I can't help you. In my own emulation experience, I've never had to look too hard to find ROMS.
Did you just download it from their site? If so then you will have to make it executable. The one I see for linux will be called SDL-Test
chmod +x SDL-Test
Then you can run it:
When I tried it, I initially got an error with my X server, but I never looked at what dependencies were needed so I wasn't that concerned. It looks like it also needs the libglademm library. After I got that it worked fine. Also, just downloading something will not put it in your menu.
If, instead, you got it from your repository (apt-get, portage, yast, etc.) then it will generally get the necessary dependencies and also place the program in your menu, but not always. If you got it through your repository, just search for the executable and you can run it from the command line or put it into your menu manually
(locate or slocate depending on the system)
The executable should be called gvba or VisualBoyAdvance. To find these files:
# locate gvba | grep bin
# locate VisualBoyAdvance | grep bin
When I try to run it using that path, it gives me this:
debian:/# locate gvba | grep bin
bash: locate: command not found
debian:/# slocate gvba | grep bin
bash: slocate: command not found
debian:/# find / -xdev -iname gvba
debian:/# find / -xdev -iname visualboyadvance
I am assuming, of course, that I am supposed to type the name of the ROM file, which I don't have.
Missing image name
/usr/bin/VisualBoyAdvance [option ...] file
It's illegal to download ROMs if you don't own the original game, but they're not hard to find. I suggest installing visualboyadvance-gtk which is a GUI for the emulator.