I'm working on an i386 bootloader and I'm running it with QEMU on my Apple Silicon machine, and everything works just fine, except I can't debug it: GDB does not (yet?) work on AS and LLDB sternly refuses to load a raw binary. This starts up fine:
$ qemu-system-i386 -s -S -drive format=raw,file=boot.bin,media=disk,if=floppy -no-fd-bootchk
but this errors out:
$ lldb boot.bin
(lldb) target create "boot.bin"
error: '/Users/morpheu5/src/boots/cube/boot.bin' doesn't contain the architecture x86_64
and I also tried this, because well, it's supposed to be i386, not x86_64:
$ lldb --arch i386 boot.bin
(lldb) target create --arch=i386 "boot.bin"
error: '/Users/morpheu5/src/boots/cube/boot.bin' doesn't contain the architecture i386
but it didn't make much of a difference. The inline help is not greatly helpful and I am having zero success searching online.
Now, I have alternatives: bochs has an internal debugger but the text-based interface is a bit clunky and I can't even figure out how to pre-set certain breakpoints -- I like to break on 0x7c00 or otherwise I have to step through the entire BIOS code -- and I can't even run the gui debugger despite having configured it with display_library: sdl2, options=gui_debug. The other alternative is a Raspberry Pi in which I could probably use gdb but I haven't tried this out yet and it's a Zero so it's not even that powerful anyway -- not that I need it, but I'd rather keep my workflow smooth...
It seems clear that lldb isn't recognizing the binary's format so I'm wondering if there's a way of just asking it to disassemble it as a 32 bit binary and just roll with it the best it can. In the end, all I really need is a way of seeing what is in memory, in the registers, and in the stack.
Any ideas?
After a few weeks of experimentation, it doesn't look like lldb is a viable option, but Bochs' command-line debugger was somewhat useful. Shame I couldn't get the GUI to run on macOS.