The assembly code that the compiler for my programming language produces, and can be assembled using GNU Assembler, works on 32-bit Linux and 32-bit FreeBSD, however, it crashes on Haiku. I do not know what I am doing wrong.
I don’t know FlatAssembly, but the everyday assembly is not platform independent language.
Sure, but if something works on Linux and FreeBSD on x86, you would kind-of-expect it to work on Haiku? Or, rather, as in the case of Windows and DOS, fail to assemble and link, rather than compile without warnings and then crash.
Haiku isn’t entirely POSIX compliant, but it’s part of the way there. Maybe your program is calling for some functionality that doesn’t exist in a library that does?