* gnu/build/linux-initrd.scm (write-cpio-archive): Remove 'open-pipe*' and
related calls. Compute list of files in 'files' variable. Use
'cpio:write-cpio-archive'. Remove #:cpio parameter.
(build-initrd): Remove #:cpio parameter.
* gnu/system/linux-initrd.scm (expression->initrd): Likewise, and adjust
BUILDER accordingly. Add (guix cpio) to #:modules.
* gnu/system/linux-initrd.scm (expression->initrd): Remove #:linux and
#:linux-modules parameters. Remove call to
'float-linux-module-directory'.
(base-initrd): Add call to 'float-linux-module-directory'. Use it in
#:linux-modules argument in the gexp. Remove #:linux and
#:linux-modules arguments to 'expression->initrd'.
* gnu/build/linux-initrd.scm (build-initrd): Remove
#:linux-module-directory parameter. Don't create 'modules'
sub-directory.
* gnu/build/linux-boot.scm (boot-system): Mentin that LINUX-MODULES is a
list of absolute file names. Don't prepend "/modules/" to
LINUX-MODULES.
* doc/guix.texi (Initial RAM Disk): Adjust accordingly.
* gnu/build/linux-initrd.scm (cache-compiled-file-name,
compile-to-cache, build-initrd): New procedures.
* gnu/system/linux-initrd.scm (expression->initrd)[builder]: Remove code
now moved above. Use 'build-initrd'.
* gnu/build/linux-initrd.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* gnu/system/linux-initrd.scm (expression->initrd): Use (gnu build
linux-initrd) and 'write-cpio-archive' instead of the inlined code.