On Fri, 2022-05-13 at 18:31 +0000, Aditya Garg wrote: > > Are there directions for installing Linux on a Mac with Apple firmware > > code? > > Well, directions of installing Linux on an Intel based Mac, which > includes the T2 Macs is the same as on a normal PC. > > Though, in case of T2 Macs, we for now need to use customised ISOs, > since some drivers and patches to support T2 Macs are yet to be > upstreamed. > > An example of installing Ubuntu can be read here on > https://wiki.t2linux.org/distributions/ubuntu/installation/ > > Talking about the official ISOs, for many distros, since > CONFIG_LOAD_UEFI_KEYS is not enabled in their kernel config, we can > install Linux using them, but they still lack many drivers required, > since they are yet to be upstreamed. So the installation doesn’t work > efficiently and we have to manually install custom kernels having > those patches. > > In some distros like Ubuntu, they have CONFIG_LOAD_UEFI_KEYS enabled > in their kernel config. In this case the crash as mentioned in the > patch description occurs and EFI Runtime Services get disabled. Since > installing GRUB requires access to NVRAM, the installation fails with > official ISOs in this case. Thus, a custom ISO, with this patch > incorporated in being used for now for users interested in Ubuntu on > T2 Macs. > > > Are you dual booting Linux and Mac, or just Linux? > > I don’t think it actually matters, though in most of the cases, we > dual boot macOS and Linux, but I do have seen cases who wipe out > their macOS completely. But this doesn't affect the Secure Boot > policy of these machines. > > > While in > > secure boot mode, without being able to read the keys to verify the > > kernel image signature, the signature verification should fail. > > If I enable secure boot in the BIOS settings (macOS Recovery), > Apple’s firmware won't allow even the boot loader like GRUB, rEFInd > to boot. It shall only allow Windows and macOS to Boot. You could see > https://support.apple.com/en-in/HT208198 for more details. > > > > > Has anyone else tested this patch? > > I work as a maintainer for Ubuntu for T2 Linux community and I have > this patch incorporated in the kernels used for Ubuntu ISOs > customised for T2 Macs, and thus have many users who have used the > ISO and have a successful installation. Thus, there are many users > who have tested this patch and are actually using it right now. > We also need the have the NVRAM writes enabled so as to unlock the > iGPU in Macs with both Intel and AMD GPU, and with this patch, we > have been successfully able to unlock it, > > I hope I could answer your questions Yes, thank you. Based on the link above and https://wiki.t2linux.org/guides/kernel/, I was able boot a kernel with/without this patch. The patch is now queued in the next-integrity-testing branch. thanks, Mimi
