Re:Grub2 security update renders system unbootable
by yrro on Thursday July 30, 2020 @01:21PM
(#24000703)
Doesn't chain loading BOOTMGR break bootlocker?
Re:Grub2 security update renders system unbootable
by vetinari on Thursday July 30, 2020 @01:29PM
(#24000802)
It doesn't chain-load as GRUB/MBR does. For UEFI boot loader, other operating systems are just EFI images. UEFI boot loaders do not care what specific OSes these images contain.
This is also used for boot time or boot repair tools. UEFI shell for example is just another EFI image.
Re:Grub2 security update renders system unbootable
by yrro on Thursday July 30, 2020 @01:38PM
(#24000900)
I thought it I validates the attestation chain so the TPM won't play ball. Hang on...
https://superuser.com/questions/1278841/bitlocker-asking-for...
I cant find the reference I'm looking for which was a decent explanation about why the days of traditional style dual booting where the Linux boot loader let's you choose between Linux or Windows using GRUB to choose between Linux and Windows were over, but that question basically covers the same ground.
Re:Grub2 security update renders system unbootable
by vetinari on Thursday July 30, 2020 @02:12PM
(#24001276)
On dual-boot machines, I've always prefered to use the built-in UEFI boot manager (yes, UEFI has one!). This way, Linux boots using systemd-boot/grub/whaever, Windows using NTLDR and whatever else is there, it uses its native way too. It avoids exactly this, where the TPM doesn't consider that there might be an additional component, properly signed, but might cause havoc with sealed values.
Yes, just press 'e' as long as editor=yes in the loader config.
> Can it boot non-Linux non-systemd OSes?
Yes, auto-entries will find Windows automatically and other EFI images can be set up through loader configs. Not sure why it wouldn't work with non-systemd systems considering that's an init system and it's a bootloader.
> Does it handle encrypted disks better than GRUB2 does?
Doesn't the initramfs handle decryption of disks?
> Does it work well if I prefer bios/dos/mbr mode?
No, it doesn't support BIOS boot.