Debugging NeoDOS

NeoDOS is typically debugged under QEMU using serial output, the QEMU monitor, and GDB.

Run QEMU

From neodos/:

neodev build --image
neodev run

This writes a full transcript to neodos/qemu_output.log.

The launch script enables the monitor on:

telnet 127.0.0.1 4444

Useful commands:

info registers
x /16x 0x4000000
info mem

The launch script enables QEMU’s GDB server on:

target remote localhost:1234

Example session:

(gdb) target remote localhost:1234
(gdb) break *0x4000000
(gdb) continue

If you don’t hit a breakpoint at 0x4000000, confirm the kernel entry printed by the bootloader and that you rebuilt the disk image.
If the shell boots but reboots later, check the serial log (qemu_output.log) first; it usually contains the panic location.