Hello, all. Looking though archives I found old script by Lubomir Rintel
for gdb. I integrated it into our build system and committed, now you
just have to run gdb -x gdb_grub from grub-core directory. It's limited
to platforms with predefined load address, so *-efi is excluded but all
others platforms should work, didn't test it with anything else than
i386-pc though.
At first I wanted to install it as well but then I noticed that it has
an important problem:
- It uses insecure temporary files. While fine if you own current
directory (like grub-core), it has to use mktemp if to be installed
globally.
- I don't know how to implement the logic "check if kernel.exec is in .,
if so use it, otherwise use @platformdir@/kernel.exec" in gdb scripts.
Note: @platformdir@ is expanded by automake.
Also I would prefer script to be less chatty and use python but it's not
very important.
I attach a simple patch to install those scripts if needed.
Also there is a serial-gdb patch in same series, while also interesting
it would need more work (and can be integrated with my another work for
backtracing on grub_fatal and exceptions)

-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko