I need to setup a kernel debug session so that I can peek & poke some registers on a PCIe HW device. I am using Ubuntu 12.04, which uses Grub2. Based on my /boot/config-3.5.0-23-generic file, the kernel was already built with KGDB support, but apparently not with kgdb-over-ethernet support. I tried building a new kernel to enable kgdboe (my target PC doesn't have an external COM port), but apparently this is no longer supported. Please correct me if I'm wrong on this, as I would really like to use ethernet if possible.
Now for the real problem: I'm trying to figure out how to modify my Grub2 config file to add an entry for KGDB. The only tutorials I've been able to find on this all refer to legacy Grub-style syntax for doing this:
kernel /boot/vmlinuz-220.127.116.11-kgdb ro root=/dev/hda1 kgdbwait kgdb8250=1,115200
The syntax for Grub2 is clearly different, as it appears the "kernel" command has been replaced with "linux", and I see a variety of other differences as well. This gives me little hope for expecting the old syntax to "just work".
I have not been able to find any instructions for configuring KGDB with Grub2 online. What is the correct way to do this? Could some one provide a sample using Grub2 syntax?