That depends how the framebuffer is configured in the kernel. It's not the boot loader that is responsible for dropping your card into graphics mode. If you're using a modular kernel then blacklist the framebuffer modules. If it is using the vesafb driver which usually is built into the kernel then you are better off recompiling the kernel. You'll have to lsmod | grep radeon to find the exact name of the module for that video card because I don't remember what its called having never compiled it into my kernels. Then you can put something like this in /etc/modprobe.d/somefile.conf blacklist radeonfborwhateverthenameofthemoduleis But just because I'm curious why would you actually want an 80x25 console?
