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authorAlbin Tonnerre <albin.tonnerre@free-electrons.com>2010-05-26 14:44:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:54 -0700
commit2a2a400f66e9e23eba960905c36dd37904bd9970 (patch)
treea46e11044410ddeb1d310fc4a1633f0438658327 /usr
parentedcd1d843adf09d1742d49ae04fa51bb63ddd1c3 (diff)
downloadlinux-2a2a400f66e9e23eba960905c36dd37904bd9970.tar.gz
initramfs: add support for in-kernel initramfs compressed with LZO
Add the necessary parts to be enable the use of LZO-compressed initramfs build into the kernel. Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'usr')
-rw-r--r--usr/Makefile5
-rw-r--r--usr/initramfs_data.lzo.S29
2 files changed, 33 insertions, 1 deletions
diff --git a/usr/Makefile b/usr/Makefile
index 1e6a9e4a72c..6b4b6da0b67 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -15,6 +15,9 @@ suffix_$(CONFIG_INITRAMFS_COMPRESSION_BZIP2) = .bz2
# Lzma
suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZMA) = .lzma
+# Lzo
+suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZO) = .lzo
+
# Generate builtin.o based on initramfs_data.o
obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data$(suffix_y).o
@@ -45,7 +48,7 @@ endif
quiet_cmd_initfs = GEN $@
cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
-targets := initramfs_data.cpio.gz initramfs_data.cpio.bz2 initramfs_data.cpio.lzma initramfs_data.cpio
+targets := initramfs_data.cpio.gz initramfs_data.cpio.bz2 initramfs_data.cpio.lzma initramfs_data.cpio.lzo initramfs_data.cpio
# do not try to update files included in initramfs
$(deps_initramfs): ;
diff --git a/usr/initramfs_data.lzo.S b/usr/initramfs_data.lzo.S
new file mode 100644
index 00000000000..59211905da8
--- /dev/null
+++ b/usr/initramfs_data.lzo.S
@@ -0,0 +1,29 @@
+/*
+ initramfs_data includes the compressed binary that is the
+ filesystem used for early user space.
+ Note: Older versions of "as" (prior to binutils 2.11.90.0.23
+ released on 2001-07-14) dit not support .incbin.
+ If you are forced to use older binutils than that then the
+ following trick can be applied to create the resulting binary:
+
+
+ ld -m elf_i386 --format binary --oformat elf32-i386 -r \
+ -T initramfs_data.scr initramfs_data.cpio.gz -o initramfs_data.o
+ ld -m elf_i386 -r -o built-in.o initramfs_data.o
+
+ initramfs_data.scr looks like this:
+SECTIONS
+{
+ .init.ramfs : { *(.data) }
+}
+
+ The above example is for i386 - the parameters vary from architectures.
+ Eventually look up LDFLAGS_BLOB in an older version of the
+ arch/$(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.lzo"