bios.rs: implement BIOS (grub)

[HuijingHei]

bootupd: Prepare bootupd update directory for both components

• Prepare bootupd update directory which will save component metadata
  files for both components.

---

Add bios.rs and implement generate_update_metadata

• This will generate /usr/lib/bootupd/updates/BIOS.json, which will have the version and timestamp of grub2-tools

---

bios.rs: implement BIOS (grub) install function

• Add --device </dev/vda> option to install BIOS bootloader (grub)
• If call function without --device, will only install EFI.

---

bios.rs: add run_update to support bootupctl update

• This is the same action as install

---

bios.rs: return Skipped when run bootupctl validate for BIOS

---

ppc64: fix build warning

• The fix looks really ugly. Just realize bootupd is not supported on ppc yet, maybe we will support in future.

---

aarch64: fix build warning

---

Fix #53

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[cgwalters]

As discussed we could probably keep this unimplemented, though it should return an error or so?

[HuijingHei]

Return Skipped for BIOS instead, does that make sense?

[root@cosa-devsh ~]# bootupctl validate
Skipped: BIOS
Validated: EFI

[HuijingHei]

Will update based on #423

[HuijingHei]

Wait, I am testing on ppc64le, and there are some errors need to be fixed.

sh-5.2# cargo build --release
   Compiling bootupd v0.2.9 (/srv/bootupd)
error[E0432]: unresolved import `crate::efi`
 --> src/bootupd.rs:4:5
  |
4 | use crate::efi;
  |     ^^^^^^^^^^ no `efi` in the root

error[E0433]: failed to resolve: could not find `efi` in the crate root
  --> src/component.rs:79:34
   |
79 |         "EFI" => Box::new(crate::efi::Efi::default()),
   |                                  ^^^ could not find `efi` in the crate root

[cgwalters]

Nice work on this!

I hadn't even realized when we started this how complex adding ppc64le would be from the conditional-compilation perspective. Thanks for plowing through all those conditionals.

I think there's some smaller things to clean up here but we can do that post-merge

Thanks so much for your work on this!

[jlebon]

This merged a while back but either forgot or never noticed it. Nice work on this @HuijingHei!

[HuijingHei]

Thanks @jlebon! Also thanks @cgwalters for lots of help!