A special META key might contain optional platform network config for
the `METAL` platform.
It is completely optional, but if present, it works same way as in the
clouds: it is applied with low priority (can be overridden with machine
config), but provides some initial defaults for the machine.
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>
Use a global instance, handle loading/saving META in global context.
Deprecate legacy syslinux ADV, provide an easier interface for
consumers.
Expose META as resources.
Fix the bootloader revert process (it was completely broken for quite a
while :sad:).
This is a first step which mostly does preparation work, real changes
will come in the next PRs:
* add APIs to write to META
* consume META keys for platform network config for `metal`
* custom key for URL `${code}`
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>
