On Mon, Jun 25, 2018 at 10:09 AM, Andrew Lutomirski <luto(a)mit.edu> wrote:
(d) It is useful to write to $BOOT from the bootloader to indicate
that we're trying to boot and again from the booted system to indicate
that the boot succeeded.
(g) The bootloader's driver for $BOOT should implement at least
reads
and preferably writes compatibly with the kernel. (With the possible
exception of F2FS, there are no crash-safe filesystems that meet this
requirement, sadly.)
This isn't reliably done through either firmware or bootloader file
system drivers for reasons I state in the immediately previous email.
But also the GRUB folks aren't ever going to write to any file system
with their drivers, no matter what that file system is. It's against
their philosophy.
What is on the table is something standardized across bootloaders,
akin to the GRUB grubenv file. It could be used for saving state where
it's not possible, reliable or desired to write to NVRAM.
--
Chris Murphy