Generators can now declare variant axes. Every generated entry is
multiplied by each combination of choices, one per axis. A choice sets
the axis name to the choice name and inserts its own values, and the
entry name is suffixed with the choice names.
Generators can also declare exclude rules, which remove generated
entries whose values match every glob pattern in a rule. This covers
unwanted variant combinations and entries like BLS rescue kernels.
Entry matching for default-entry and the bootloader interface now
accepts `*` anywhere in the pattern instead of only at the end, so
generated entry names can be matched regardless of the kernel version
in the middle of the name.
The BLS generator gains a pin-names option (default true, the existing
behavior). Two BLS generators reading the same directory previously
produced entries with identical names; disabling pin-names prefixes
them with the generator name instead. Sprout now warns when more than
one entry has the same name.
* docs(config): note that variants suffix pinned BLS entry names
Pinned BLS entry names match the BLS entry ids, but variants still
append their choice names, so those entries need a pattern like
<id>-* to be selected.
BLS was detected when reading \loader\entries produced any item, but a
FAT directory always lists "." first, so an empty entries directory
counted as having entries. On an ESP with a leftover empty entries
directory, Linux autoconfiguration was skipped and no Linux entries
were shown. Only count the directory when it has a .conf file.
Add linux-initrd-chain to the chainload action and initrd-chain to the
edera action. Each file in the list is read in order and concatenated
into a single initrd. The chain can't be combined with the single
initrd option on the same action.
BLS entries with multiple initrds, either as repeated initrd lines or
as multiple paths on one line, previously only loaded the last one.
Parse all of them and set them in the initrd-0 through initrd-7 slots,
which the autoconfigured BLS action now chains. Unused slots stamp to
the filesystem root and are skipped. Entries with more than 8 initrds
are skipped with a warning.