Implement --[no-]compress-initramfs option to complement --[no-]integrated-initramfs

When using an integrated initramfs (including in kernel during build),
it's better NOT to compress the initramfs, as the kernel build process
will then be re-compressing it. This can provide space savings on disk
as well as potential time & memory savings (one less decompress pass is
needed before the kernel can use the initramfs).

This functionality was previously available in the undocumented
COMPRESS_INITRD variable.

Code-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
(commit message rewritten).

arch/alpha/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE="boot"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="arch/alpha/boot/vmlinux.gz"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/arm/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE=""
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="arch/arm/boot/zImage"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/ia64/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE=""
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="vmlinux.gz"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/mips/config.sh

@@ -7,7 +7,6 @@ KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="./vmlinux"
 
 # Initrd/Initramfs Options
-COMPRESS_INITRD="yes"
 USECOLOR="yes"
 NOINITRDMODULES="yes"
 BUSYBOX=1
@@ -22,6 +21,7 @@ CMD_INSTALL=0
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD="yes"
 DEFAULT_KERNEL_MAKE=make
 DEFAULT_UTILS_MAKE=make
 DEFAULT_UTILS_CC=gcc

arch/parisc/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE="vmlinux"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="vmlinux"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/parisc64/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE="vmlinux"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="vmlinux"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/ppc/config.sh

@@ -5,12 +5,12 @@
 KERNEL_MAKE_DIRECTIVE="vmlinux"
 KERNEL_BINARY="vmlinux"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/ppc64/config.sh

@@ -5,12 +5,12 @@
 KERNEL_MAKE_DIRECTIVE="vmlinux"
 KERNEL_BINARY="vmlinux"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/sparc/config.sh

@@ -6,13 +6,14 @@ KERNEL_MAKE_DIRECTIVE="vmlinux"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="vmlinux"
 
-COMPRESS_INITRD=yes
 USECOLOR="no"
 
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j1"
 
 DEFAULT_KERNEL_MAKE=make

arch/sparc64/config.sh

@@ -6,13 +6,14 @@ KERNEL_MAKE_DIRECTIVE="vmlinux"
 KERNEL_MAKE_DIRECTIVE_2="image"
 KERNEL_BINARY="arch/sparc64/boot/image arch/sparc/boot/image"
 
-COMPRESS_INITRD=yes
 USECOLOR="no"
 
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/um/config.sh

@@ -6,13 +6,14 @@ KERNEL_MAKE_DIRECTIVE="linux"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="linux"
 
-COMPRESS_INITRD=yes
 ARCH_HAVENOPREPARE=yes
 
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE="make ARCH=um"

arch/x86/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE="bzImage"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="arch/i386/boot/bzImage"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

arch/x86_64/config.sh

@@ -6,12 +6,12 @@ KERNEL_MAKE_DIRECTIVE="bzImage"
 KERNEL_MAKE_DIRECTIVE_2=""
 KERNEL_BINARY="arch/x86_64/boot/bzImage"
 
-COMPRESS_INITRD=yes
-
 #
 # Arch-specific defaults that can be overridden in the config file or on the
 # command line.
 #
+DEFAULT_COMPRESS_INITRD=yes
+
 DEFAULT_MAKEOPTS="-j2"
 
 DEFAULT_KERNEL_MAKE=make

doc/genkernel.8.txt

@@ -361,6 +361,9 @@ OUTPUT SETTINGS
 	Builds or does not build the generated initramfs into the kernel instead
 	of keeping it as a separate file.
 
+*--*[*no-*]*compress-initramfs*::
+	Compresses or does not compress the generated initramfs.
+
 
 RAMDISK OPTIONS
 ---------------

gen_cmdline.sh

@@ -149,6 +149,8 @@ longusage() {
   echo "	--integrated-initramfs, --no-integrated-initramfs"
   echo "				Include/exclude the generated initramfs in the kernel"
   echo "				instead of keeping it as a separate file"
+  echo "	--compress-initramfs, --no-compress-initramfs"
+  echo "				Compress or do not compress the generated initramfs"
 }
 
 usage() {
@@ -529,6 +531,10 @@ parse_cmdline() {
 			CMD_INTEGRATED_INITRAMFS=`parse_optbool "$*"`
 			print_info 2 "CMD_INTEGRATED_INITRAMFS=${CMD_INTEGRATED_INITRAMFS}"
 			;;
+		--compress-initramfs|--no-compress-initramfs)
+			CMD_COMPRESS_INITRD=`parse_optbool "$*"`
+			print_info 2 "CMD_COMPRESS_INITRD=${CMD_COMPRESS_INITRD}"
+			;;
 		--config=*)
 			print_info 2 "CMD_GK_CONFIG: `parse_opt "$*"`"
 			;;

gen_determineargs.sh

@@ -75,6 +75,7 @@ determine_real_args() {
 	set_config_with_override BOOL   KERNEL_SOURCES       CMD_KERNEL_SOURCES       "yes"
 	set_config_with_override STRING KNAME                CMD_KERNNAME             "genkernel"
 
+	set_config_with_override STRING COMPRESS_INITRD      CMD_COMPRESS_INITRD      "$DEFAULT_COMPRESS_INITRD"
 	set_config_with_override STRING MAKEOPTS             CMD_MAKEOPTS             "$DEFAULT_MAKEOPTS"
 	set_config_with_override STRING KERNEL_MAKE          CMD_KERNEL_MAKE          "$DEFAULT_KERNEL_MAKE"
 	set_config_with_override STRING UTILS_MAKE           CMD_UTILS_MAKE           "$DEFAULT_UTILS_MAKE"

gen_initramfs.sh

@@ -631,6 +631,7 @@ append_data() {
 }
 
 create_initramfs() {
+	local compress_ext=""
 	print_info 1 "initramfs: >> Initializing..."
 
 	# Create empty cpio
@@ -673,16 +674,23 @@ create_initramfs() {
 		append_data 'overlay'
 	fi
 
-	gzip -9 "${CPIO}"
+	# Implement support for disabling compression
-	mv -f "${CPIO}.gz" "${CPIO}"
+	if isTrue "${COMPRESS_INITRD}"
+	then
+		compress_ext=".gz"
+		print_info 1 "        >> Compressing cpio data..."
+		gzip -9 "${CPIO}" || gen_die "Compression failed"
+		mv -f "${CPIO}.gz" "${CPIO}" || gen_die "Rename failed"
+	fi
+
 
 	if isTrue "${INTEGRATED_INITRAMFS}"
 	then
 #		cp ${TMPDIR}/initramfs-${KV} ${KERNEL_DIR}/usr/initramfs_data.cpio.gz
-		mv ${TMPDIR}/initramfs-${KV} ${TMPDIR}/initramfs-${KV}.cpio.gz
+		mv ${TMPDIR}/initramfs-${KV} ${TMPDIR}/initramfs-${KV}.cpio${compress_ext}
 #		sed -i "s|^.*CONFIG_INITRAMFS_SOURCE=.*$|CONFIG_INITRAMFS_SOURCE=\"${TMPDIR}/initramfs-${KV}.cpio.gz\"|" ${KERNEL_DIR}/.config
 		sed -i '/^.*CONFIG_INITRAMFS_SOURCE=.*$/d' ${KERNEL_DIR}/.config
-		echo -e "CONFIG_INITRAMFS_SOURCE=\"${TMPDIR}/initramfs-${KV}.cpio.gz\"\nCONFIG_INITRAMFS_ROOT_UID=0\nCONFIG_INITRAMFS_ROOT_GID=0" >> ${KERNEL_DIR}/.config
+		echo -e "CONFIG_INITRAMFS_SOURCE=\"${TMPDIR}/initramfs-${KV}.cpio${compress_ext}\"\nCONFIG_INITRAMFS_ROOT_UID=0\nCONFIG_INITRAMFS_ROOT_GID=0" >> ${KERNEL_DIR}/.config
 	fi
 
 	if isTrue "${CMD_INSTALL}"

genkernel.conf

@@ -317,6 +317,10 @@ GPG_BINCACHE="%%CACHE%%/gnupg-${GPG_VER}-%%ARCH%%.bz2"
 #INTEGRATED_INITRAMFS="1"
 
 
+# Compress generated initramfs
+#COMPRESS_INITRD="yes"
+
+
 # Create a self-contained env in the initramfs
 #NETBOOT="1"