I went with a simpler implementation that uses Go compression packages
to do the work. The downside of this is that the compression Level is a
bit weird to set, since most libraries discourage setting the numeric
compression level directly.
This is configured by setting `deviceinfo_initfs_compression`, the value
it expects is a string in the form: `FORMAT[:LEVEL]`, where `[:LEVEL]`
is optional. Actually setting the variable at all is optional... if
nothing is specified, or it can't parse the format/level from the string
value, it defaults to using gzip with the "default" level for the
package (which tries to mirror gzip's default, or something).
The level can be one of `default`, `fast`, `best`.
To configure gzip with the fastest compression (so, bigger size): deviceinfo_initfs_compression="gzip:fast"`
To configure zstd with the most compression: `deviceinfo_initfs_compression="zstd:best"`
To configure zstd with default compression: `deviceinfo_initfs_compression="zstd"` (or `deviceinfo_initfs_compression="zstd:default"`)
In this case, `gzip:default` is assumed: deviceinfo_initfs_compression="bananas:mmmm"`
This new style is a little more verbose (having to manually set return
code on error..), but at least it offers a chance to improve the
printing of errors a little more.
This is kinda janky, passing both a list of modules and a directory path
is just because we support modules in deviceinfo and in directory file
lists... Maybe one day we can move away from having modules in the
deviceinfo...
This moves the main package to cmd/mkinitfs, and configures the compiled
binary to be named 'mkinitfs'. calling the full name
'postmarketos-mkinitfs' was unlikely to be used by anyone...
This move makes the project source layout more consistent with other Go
projects, and allows for adding more cmd/* things with their own main
packages later if we want
