6 files changed, 201 insertions, 13 deletions

diff --git a/usr/Kconfig b/usr/Kconfig
index 86cecb59dd07..43a3a0fe8f29 100644
--- a/usr/Kconfig
+++ b/usr/Kconfig
@@ -44,3 +44,92 @@ config INITRAMFS_ROOT_GID
           owned by group root in the initial ramdisk image.
 
           If you are not sure, leave it set to "0".
+
+config RD_GZIP
+        bool "Initial ramdisk compressed using gzip"
+        default y
+        depends on BLK_DEV_INITRD=y
+        select DECOMPRESS_GZIP
+        help
+          Support loading of a gzip encoded initial ramdisk or cpio buffer.
+          If unsure, say Y.
+
+config RD_BZIP2
+        bool "Initial ramdisk compressed using bzip2"
+        default n
+        depends on BLK_DEV_INITRD=y
+        select DECOMPRESS_BZIP2
+        help
+          Support loading of a bzip2 encoded initial ramdisk or cpio buffer
+          If unsure, say N.
+
+config RD_LZMA
+        bool "Initial ramdisk compressed using lzma"
+        default n
+        depends on BLK_DEV_INITRD=y
+        select DECOMPRESS_LZMA
+        help
+          Support loading of a lzma encoded initial ramdisk or cpio buffer
+          If unsure, say N.
+
+choice
+        prompt "Built-in initramfs compression mode"
+        help
+          This setting is only meaningful if the INITRAMFS_SOURCE is
+          set. It decides by which algorithm the INITRAMFS_SOURCE will
+          be compressed.
+          Several compression algorithms are available, which differ
+          in efficiency, compression and decompression speed.
+          Compression speed is only relevant when building a kernel.
+          Decompression speed is relevant at each boot.
+
+          If you have any problems with bzip2 or lzma compressed
+          initramfs, mail me (Alain Knaff) <alain@knaff.lu>.
+
+          High compression options are mostly useful for users who
+          are low on disk space (embedded systems), but for whom ram
+          size matters less.
+
+          If in doubt, select 'gzip'
+
+config INITRAMFS_COMPRESSION_NONE
+        bool "None"
+        help
+          Do not compress the built-in initramfs at all. This may
+          sound wasteful in space, but, you should be aware that the
+          built-in initramfs will be compressed at a later stage
+          anyways along with the rest of the kernel, on those
+          architectures that support this.
+          However, not compressing the initramfs may lead to slightly
+          higher memory consumption during a short time at boot, while
+          both the cpio image and the unpacked filesystem image will
+          be present in memory simultaneously
+
+config INITRAMFS_COMPRESSION_GZIP
+        bool "Gzip"
+        depends on RD_GZIP
+        help
+          The old and tried gzip compression. Its compression ratio is
+          the poorest among the 3 choices; however its speed (both
+          compression and decompression) is the fastest.
+
+config INITRAMFS_COMPRESSION_BZIP2
+        bool "Bzip2"
+        depends on RD_BZIP2
+        help
+          Its compression ratio and speed is intermediate.
+          Decompression speed is slowest among the three.  The initramfs
+          size is about 10% smaller with bzip2, in comparison to gzip.
+          Bzip2 uses a large amount of memory. For modern kernels you
+          will need at least 8MB RAM or more for booting.
+
+config INITRAMFS_COMPRESSION_LZMA
+        bool "LZMA"
+        depends on RD_LZMA
+        help
+          The most recent compression algorithm.
+          Its ratio is best, decompression speed is between the other
+          two. Compression is slowest.  The initramfs size is about 33%
+          smaller with LZMA in comparison to gzip.
+
+endchoice
diff --git a/usr/Makefile b/usr/Makefile
index 201f27f8cbaf..b84894b3929d 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -6,13 +6,25 @@ klibcdirs:;
 PHONY += klibcdirs
 
 
+# No compression
+suffix_$(CONFIG_INITRAMFS_COMPRESSION_NONE)   =
+
+# Gzip, but no bzip2
+suffix_$(CONFIG_INITRAMFS_COMPRESSION_GZIP)   = .gz
+
+# Bzip2
+suffix_$(CONFIG_INITRAMFS_COMPRESSION_BZIP2)  = .bz2
+
+# Lzma
+suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZMA)   = .lzma
+
 # Generate builtin.o based on initramfs_data.o
-obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
+obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data$(suffix_y).o
 
-# initramfs_data.o contains the initramfs_data.cpio.gz image.
+# initramfs_data.o contains the compressed initramfs_data.cpio image.
 # The image is included using .incbin, a dependency which is not
 # tracked automatically.
-$(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio.gz FORCE
+$(obj)/initramfs_data$(suffix_y).o: $(obj)/initramfs_data.cpio$(suffix_y) FORCE
 
 #####
 # Generate the initramfs cpio archive
@@ -25,28 +37,28 @@ ramfs-args  := \
         $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
         $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
 
-# .initramfs_data.cpio.gz.d is used to identify all files included
+# .initramfs_data.cpio.d is used to identify all files included
 # in initramfs and to detect if any files are added/removed.
 # Removed files are identified by directory timestamp being updated
 # The dependency list is generated by gen_initramfs.sh -l
-ifneq ($(wildcard $(obj)/.initramfs_data.cpio.gz.d),)
-        include $(obj)/.initramfs_data.cpio.gz.d
+ifneq ($(wildcard $(obj)/.initramfs_data.cpio.d),)
+        include $(obj)/.initramfs_data.cpio.d
 endif
 
 quiet_cmd_initfs = GEN     $@
       cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
 
-targets := initramfs_data.cpio.gz
+targets := initramfs_data.cpio.gz initramfs_data.cpio.bz2 initramfs_data.cpio.lzma initramfs_data.cpio
 # do not try to update files included in initramfs
 $(deps_initramfs): ;
 
 $(deps_initramfs): klibcdirs
-# We rebuild initramfs_data.cpio.gz if:
-# 1) Any included file is newer then initramfs_data.cpio.gz
+# We rebuild initramfs_data.cpio if:
+# 1) Any included file is newer then initramfs_data.cpio
 # 2) There are changes in which files are included (added or deleted)
-# 3) If gen_init_cpio are newer than initramfs_data.cpio.gz
+# 3) If gen_init_cpio are newer than initramfs_data.cpio
 # 4) arguments to gen_initramfs.sh changes
-$(obj)/initramfs_data.cpio.gz: $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
-        $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.gz.d
+$(obj)/initramfs_data.cpio$(suffix_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
+        $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.d
         $(call if_changed,initfs)
 
diff --git a/usr/initramfs_data.S b/usr/initramfs_data.S
index c2e1ad424f4a..7c6973d8d829 100644
--- a/usr/initramfs_data.S
+++ b/usr/initramfs_data.S
@@ -26,5 +26,5 @@ SECTIONS
 */
 
 .section .init.ramfs,"a"
-.incbin "usr/initramfs_data.cpio.gz"
+.incbin "usr/initramfs_data.cpio"
 
diff --git a/usr/initramfs_data.bz2.S b/usr/initramfs_data.bz2.S
new file mode 100644
index 000000000000..bc54d090365c
--- /dev/null
+++ b/usr/initramfs_data.bz2.S
@@ -0,0 +1,29 @@
+/*
+  initramfs_data includes the compressed binary that is the
+  filesystem used for early user space.
+  Note: Older versions of "as" (prior to binutils 2.11.90.0.23
+  released on 2001-07-14) dit not support .incbin.
+  If you are forced to use older binutils than that then the
+  following trick can be applied to create the resulting binary:
+
+
+  ld -m elf_i386  --format binary --oformat elf32-i386 -r \
+  -T initramfs_data.scr initramfs_data.cpio.gz -o initramfs_data.o
+   ld -m elf_i386  -r -o built-in.o initramfs_data.o
+
+  initramfs_data.scr looks like this:
+SECTIONS
+{
+       .init.ramfs : { *(.data) }
+}
+
+  The above example is for i386 - the parameters vary from architectures.
+  Eventually look up LDFLAGS_BLOB in an older version of the
+  arch/$(ARCH)/Makefile to see the flags used before .incbin was introduced.
+
+  Using .incbin has the advantage over ld that the correct flags are set
+  in the ELF header, as required by certain architectures.
+*/
+
+.section .init.ramfs,"a"
+.incbin "usr/initramfs_data.cpio.bz2"
diff --git a/usr/initramfs_data.gz.S b/usr/initramfs_data.gz.S
new file mode 100644
index 000000000000..890c8dd1d6bd
--- /dev/null
+++ b/usr/initramfs_data.gz.S
@@ -0,0 +1,29 @@
+/*
+  initramfs_data includes the compressed binary that is the
+  filesystem used for early user space.
+  Note: Older versions of "as" (prior to binutils 2.11.90.0.23
+  released on 2001-07-14) dit not support .incbin.
+  If you are forced to use older binutils than that then the
+  following trick can be applied to create the resulting binary:
+
+
+  ld -m elf_i386  --format binary --oformat elf32-i386 -r \
+  -T initramfs_data.scr initramfs_data.cpio.gz -o initramfs_data.o
+   ld -m elf_i386  -r -o built-in.o initramfs_data.o
+
+  initramfs_data.scr looks like this:
+SECTIONS
+{
+       .init.ramfs : { *(.data) }
+}
+
+  The above example is for i386 - the parameters vary from architectures.
+  Eventually look up LDFLAGS_BLOB in an older version of the
+  arch/$(ARCH)/Makefile to see the flags used before .incbin was introduced.
+
+  Using .incbin has the advantage over ld that the correct flags are set
+  in the ELF header, as required by certain architectures.
+*/
+
+.section .init.ramfs,"a"
+.incbin "usr/initramfs_data.cpio.gz"
diff --git a/usr/initramfs_data.lzma.S b/usr/initramfs_data.lzma.S
new file mode 100644
index 000000000000..e11469e48562
--- /dev/null
+++ b/usr/initramfs_data.lzma.S
@@ -0,0 +1,29 @@
+/*
+  initramfs_data includes the compressed binary that is the
+  filesystem used for early user space.
+  Note: Older versions of "as" (prior to binutils 2.11.90.0.23
+  released on 2001-07-14) dit not support .incbin.
+  If you are forced to use older binutils than that then the
+  following trick can be applied to create the resulting binary:
+
+
+  ld -m elf_i386  --format binary --oformat elf32-i386 -r \
+  -T initramfs_data.scr initramfs_data.cpio.gz -o initramfs_data.o
+   ld -m elf_i386  -r -o built-in.o initramfs_data.o
+
+  initramfs_data.scr looks like this:
+SECTIONS
+{
+       .init.ramfs : { *(.data) }
+}
+
+  The above example is for i386 - the parameters vary from architectures.
+  Eventually look up LDFLAGS_BLOB in an older version of the
+  arch/$(ARCH)/Makefile to see the flags used before .incbin was introduced.
+
+  Using .incbin has the advantage over ld that the correct flags are set
+  in the ELF header, as required by certain architectures.
+*/
+
+.section .init.ramfs,"a"
+.incbin "usr/initramfs_data.cpio.lzma"