* guix/build/linux-initrd.scm (make-essential-device-nodes): Make
/dev/fuse.
(boot-system): Add #:unionfs parameter. Invoke UNIONFS instead of
copying files over when VOLATILE-ROOT? is true.
* gnu/system/linux-initrd.scm (expression->initrd): Add #:inputs
parameter.
[files-to-copy]: New procedure.
[builder]: Add 'to-copy' parameter; honor it.
(qemu-initrd)[linux-modules]: Add 'fuse.ko' when VOLATILE-ROOT?.
Pass UNIONFS-FUSE/STATIC as #:inputs; change builder to pass #:unionfs
to 'boot-system'.
1c96c1bbab