This generates `lzbt-systemd` binary instead of `lzbt`
which is using a special systemd-specific entrypoint.
This is part of the effort to enable multiple backends.
We introduce `linux-bootloader` a crate made to build Rust-based Linux-oriented bootloaders.
It follows systemd/UAPI group and semantics as much as possible, e.g. BLS/loader capabilities/stub capabilities.
A compile time feature is introduced that allows to build "fat" stubs
that can be used to build "fat" UKIs. "fat" here means that the actual
kernel and initrd are embedded in the PE binary, not only the file path
and hash. This brings us one step closer to feature partiy with
systemd-stub and thus one step closer to replacing it fully. Such a
"fat" or "real" UKI is also interesting for image-based deployments of
NixOS.
Bootspec has a mechanism called synthesis where you can synthesize
bootspecs if they are not present based on the generation link only.
This is useful for "vanilla bootspec" which does not contain any
extensions, as this is what we do right now.
If we need extensions, we can also implement our synthesis mechanism on
the top of it.
Enabling synthesis gives us the superpower to support non-bootspec
users. :-)
The message about malformed generatiosn should semantically be a
warning. However, since users might have hundres of old and thus
malformed generations and can do little about it, this should remain a
debug message. This way the user is not spammed with no-op warnings
while still enabling debugging.
lzbt currently happily nukes all boot entries, if it can't parse any
bootspecs. With the upcoming incompatible bootspec change, this might
be a problem that's worth avoiding. :)
I changed lzbt to fail hard in case, it can't generate any boot
items.
People reportedly want to compile the stub on i686 and AArch64
platforms for testing. Make compilation possible by providing proper
`make_instruction_cache_coherent` implementations on these platforms.
For x86 (just as x86_64), this is a no-op, because Intel made the
instruction cache coherent for compatibility with code that was written
before caches existed.
For AArch64, adapt the procedure from their manual to multiple
instructions.
nikstur