Merge pull request #1860 from tlaurion/fix_initrd_unpack_for_repacking

initrd/bin/unpack_initramfs.sh: add xz unpacking support.

initrd/bin/unpack_initramfs.sh

@@ -45,7 +45,10 @@ consume_zeros() {
 
 unpack_cpio() {
 	TRACE_FUNC
-    (cd "$dest_dir"; cpio -i "${CPIO_ARGS[@]}" 2>/dev/null)
+	(
+		cd "$dest_dir"
+		cpio -i "${CPIO_ARGS[@]}" 2>/dev/null
+	)
 }
 
 # unpack the first segment of an archive, then write the rest to another file
@@ -72,14 +75,14 @@ unpack_first_segment() {
 			# Copy the remaining data
 			cat
 			;;
-            303730373031*|303730373032*)    # plain cpio
+		303730373031* | 303730373032*) # plain cpio
 			DEBUG "archive segment $magic: plain cpio"
 			# Unpack the plain cpio, this stops reading after the trailer
 			unpack_cpio
 			# Copy the remaining data
 			cat
 			;;
-            1f8b*|1f9e*)    # gzip
+		1f8b* | 1f9e*) # gzip
 			DEBUG "archive segment $magic: gzip"
 			# gunzip won't stop when reaching the end of the gzipped member,
 			# so we can't read another segment after this.  We can't
@@ -87,6 +90,10 @@ unpack_first_segment() {
 			# walking all the compressed blocks.
 			gunzip | unpack_cpio
 			;;
+		fd37*) # xz
+			DEBUG "archive segment $magic: xz"
+			unxz | unpack_cpio
+			;;
 		28b5*) # zstd
 			DEBUG "archive segment $magic: zstd"
 			# Like gunzip, this will not stop when reaching the end of the
@@ -96,6 +103,26 @@ unpack_first_segment() {
 			;;
 		*) # unknown
 			die "Can't decompress initramfs archive, unknown type: $magic"
+			# The following are magic values for other compression formats
+			#  but not added because not tested.
+			# TODO: open an issue for unsupported magic number reported on die.
+			# 
+			#425a*) # bzip2
+			#	DEBUG "archive segment $magic: bzip2"
+			#	bunzip2 | unpack_cpio
+			#;;
+			#5d00*) # lzma
+			#	DEBUG "archive segment $magic: lzma"
+			#	unlzma | unpack_cpio
+			#;;
+			#894c*) # lzo
+			#	DEBUG "archive segment $magic: lzo"
+			#	lzop -d | unpack_cpio
+			#;;
+			#0221*) # lz4
+			#	DEBUG "archive segment $magic: lz4"
+			#	lz4 -d | unpack_cpio
+			#	;;
 			;;
 		esac
 	) <"$unpack_archive" >"$rest_archive"