I have a Debian system that is unable to boot a configuration I want. I don't have physical access to it, but I have serial-over-LAN access via Dell's BMC (so very limited), IPMI 1.5/isol. When I boot the machine, BIOS messages etc show up just fine. When I get to GRUB, however, everything goes bad.
I get either a white-on-white screen after reversed
WELCOME TO GRUB message, or if I try to set consoles that don't show colors, I get a screenful of ÿ:s. The latter could also happen with incorrect serial settings, but since BIOS shows up fine, I can send arrow keys/enter to GRUB and Linux login shows up just fine, I don't think that's the case. If serial speed was wrong, it wouldn't allow me to select a menu setting and boot it.
When I select a boot configuration, nothing happens on screen until I get either reboot or login console. So I get no information about what's wrong with the boot options.
I've tried to set grub.cfg to white/black for menu_color_normal, color_normal etc, but nothing changes. Probably GRUB still sends some color commands.
Can anyone tell me how to get rid of all color stuff from GRUB? Or do I have to try to install LILO or something else to get a bootloader that would actually just boot and nothing else? All information on the net is basically the opposite: how to add colors/images/graphics modes.
Tried GRUB 1.98 and 2.02, both behave exactly the same. Configuration is otherwise Debian 8 default, except tried the color changes. Connecting via ipmitools or Dell's solproxy+telnet (tried Windows internal, PuTTy)