[ubuntu] [mactel] Accessing the GRUB menu

Hi!

I've been playing with Ubuntu on Intel Macs for a while, and have discovered that Bootcamp seems to ignore keyboard input when GRUB is chainloaded. This prevents me from being able to access the GRUB menu to select things like MemTest86+ and Recovery Mode.

Now, I've worked out a couple of alternative ways to access it such as using grub-reboot, or doing a cold shutdown to bring it up. But I'm wondering, is there a way to access the GRUB menu during a standard boot like with PCs (i.e., holding shift when GRUB loads)?

Thanks!