David Christensen wrote: > debian-user: > > I have an Apple MacBook Pro (Retina, 15-inch, Mid 2015) with an Intel Core > i7-4770HQ processor, 16 GB memory, and 256 GB SSD: > > > If I now power up the machine with the buster-mac USB flash drive installed, > Debian starts. > > > > If I now power up the machine without the buster-mac USB flash drive > installed and hold the Option key, I see the MacBook firmware disk window > showing the internal SSD. Selecting the internal SSD starts macOS. > > > If I now power up the machine without the buster-mac USB flash drive > installed and hold the Command-R keys, I see the MacBook firmware POST > screen, then the MacBook firmware utilities window. Selecting Disk Utility > and View -> Show All Devices, I see:
I am pretty sure you didn't want to install GRUB at all -- the Mac's own EFI booter should work on your USB stick; it's invoked by holding down option at boot time. -dsr-
