1 files changed, 39 insertions, 0 deletions
diff --git a/pkgs/build-support/kernel/make-initrd.sh b/pkgs/build-support/kernel/make-initrd.sh
new file mode 100644
index 000000000000..d930e51a03f9
--- /dev/null
+++ b/pkgs/build-support/kernel/make-initrd.sh
@@ -0,0 +1,39 @@
+source $stdenv/setup
+
+set -o pipefail
+
+objects=($objects)
+symlinks=($symlinks)
+suffices=($suffices)
+
+mkdir root
+
+# Needed for splash_helper, which gets run before init.
+mkdir root/dev
+mkdir root/sys
+mkdir root/proc
+
+
+for ((n = 0; n < ${#objects[*]}; n++)); do
+    object=${objects[$n]}
+    symlink=${symlinks[$n]}
+    suffix=${suffices[$n]}
+    if test "$suffix" = none; then suffix=; fi
+
+    mkdir -p $(dirname root/$symlink)
+    ln -s $object$suffix root/$symlink
+done
+
+
+# Get the paths in the closure of `object'.
+storePaths=$(perl $pathsFromGraph closure-*)
+
+
+# Paths in cpio archives *must* be relative, otherwise the kernel
+# won't unpack 'em.
+(cd root && cp -prd --parents $storePaths .)
+
+
+# Put the closure in a gzipped cpio archive.
+ensureDir $out
+(cd root && find * -print0 | cpio -ov -H newc --null | gzip -9 > $out/initrd)