GAS and ELF support

[atirut-w]

Upstream GNU Binutils (and the assembler) supports Z80, and ELF files can have a lot of useful information (e.g. where to load, entry point address, etc.), so this would be very useful especially for anything involving ELF. A personal use case of mine would also benefit from this.

[maziac]

The problem with the Z80 assemblers is that they usually don't provide enough information for banking.
Historically DeZog supports z80asm, z88dk. But only sjasmplus supports proper banking information.

I was happy that the maintainer of sjasmplus was able to add this information in a new output format (additionally to the lst format).
I doubt that it will be provided by gas.

But if you would like to try you can fork dezog.
There is also documentation available for adding an assembler: https://github.com/maziac/DeZog/blob/main/design/AddingNewAssemblers.md

[atirut-w]

The problem with the Z80 assemblers is that they usually don't provide enough information for banking.
Historically DeZog supports z80asm, z88dk. But only sjasmplus supports proper banking information.

Why would that be a problem? It's fine if a format doesn't have banking information considering you can already load flat binaries. In this case, ELF could be treated as a file with loadObjs information.