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authorArnout Vandecappelle (Essensium/Mind) <arnout@mind.be>2011-09-06 21:16:09 (GMT)
committer Peter Korsgaard <jacmet@sunsite.dk>2011-09-27 20:46:00 (GMT)
commit13a3afc536b845e8de8eea9b91bbc6e7430c4566 (patch)
treee6c12ef1dc34eb5d70877b6c3c7a880958ddce34
parent3fac21ef8d794b47f731003b399e704349c54346 (diff)
downloadbuildroot-13a3afc536b845e8de8eea9b91bbc6e7430c4566.tar.gz
buildroot-13a3afc536b845e8de8eea9b91bbc6e7430c4566.tar.bz2
fs/initramfs: refactor with fs/cpio
An initramfs is in fact the same as a cpio archive, but embedded in the kernel. So instead of duplicating the cpio infrastructure, we can simply build images/rootfs.cpio and link that into the kernel. Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
-rw-r--r--fs/initramfs/Config.in13
-rw-r--r--fs/initramfs/gen_initramfs_list.sh203
-rwxr-xr-xfs/initramfs/init7
-rw-r--r--fs/initramfs/initramfs.mk35
-rw-r--r--linux/linux.mk17
5 files changed, 25 insertions, 250 deletions
diff --git a/fs/initramfs/Config.in b/fs/initramfs/Config.in
index abb3c0c..bbc2ab0 100644
--- a/fs/initramfs/Config.in
+++ b/fs/initramfs/Config.in
@@ -1,20 +1,21 @@
config BR2_TARGET_ROOTFS_INITRAMFS
bool "initramfs for initial ramdisk of linux kernel"
depends on BR2_LINUX_KERNEL
+ select BR2_TARGET_ROOTFS_CPIO
help
Integrate the root filesystem generated by Buildroot as an
initramfs inside the kernel image. This integration will
take place automatically.
- The rootfs.initramfs file generated in the images/ directory
- is only a text file describing the contents of the initramfs
- in a format understood by the CONFIG_INITRAMFS_SOURCE kernel
- configuration option.
+ A rootfs.cpio file will be generated in the images/ directory.
+ This is the archive that will be included in the kernel image.
+ The rootfs in the kernel will always be gzip'ed, regardless
+ of how buildroot's cpio archive is configured.
- Note that enabling initramfs together with other filesystem
+ Note that enabling initramfs together with another filesystem
formats doesn't make sense: you would end up having two
identical root filesystems, one embedded inside the kernel
- image, and one separatly.
+ image, and one separately.
comment "initramfs requires a Linux kernel to be built"
depends on !BR2_LINUX_KERNEL
diff --git a/fs/initramfs/gen_initramfs_list.sh b/fs/initramfs/gen_initramfs_list.sh
deleted file mode 100644
index 26252b6..0000000
--- a/fs/initramfs/gen_initramfs_list.sh
+++ /dev/null
@@ -1,203 +0,0 @@
-#!/bin/sh
-# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
-# Released under the terms of the GNU GPL
-#
-# Generate a newline separated list of entries from the file/directory
-# supplied as an argument.
-#
-# If a file/directory is not supplied then generate a small dummy file.
-#
-# The output is suitable for gen_init_cpio built from usr/gen_init_cpio.c.
-#
-
-default_initramfs() {
- cat <<-EOF
- # This is a very simple, default initramfs
-
- dir /dev 0755 0 0
- nod /dev/console 0600 0 0 c 5 1
- dir /root 0700 0 0
- EOF
-}
-
-filetype() {
- local argv1="$1"
-
- # symlink test must come before file test
- if [ -L "$argv1" ]; then
- echo "slink"
- elif [ -f "$argv1" ]; then
- echo "file"
- elif [ -d "$argv1" ]; then
- echo "dir"
- elif [ -b "$argv1" -o -c "$argv1" ]; then
- echo "nod"
- elif [ -p "$argv1" ]; then
- echo "pipe"
- elif [ -S "$argv1" ]; then
- echo "sock"
- else
- echo "invalid"
- fi
- return 0
-}
-
-print_mtime() {
- local argv1="$1"
- local mymtime="0"
-
- if [ -e "$argv1" ]; then
- mymtime=$(find "$argv1" -printf "%T@\n" | sort -r | head -n 1)
- fi
-
- echo "# Last modified: $mymtime"
- echo
-}
-
-parse() {
- local location="$1"
- local name=$(echo "$location" | sed -e "s,$srcdir,,")
- # change '//' into '/'
- name=$(echo $name | sed -e 's,/[/]*,/,g')
- local mode="$2"
- local uid="$3"
- local gid="$4"
- local ftype=$(filetype "$location")
- # remap uid/gid to 0 if necessary
- [ "x$uid" != "x" ] && [ $uid -eq $root_uid ] && uid=0
- [ "x$gid" != "x" ] && [ $gid -eq $root_gid ] && gid=0
- local str="$mode $uid $gid"
-
- [ "$ftype" = "invalid" ] && return 0
- [ "$location" = "$srcdir" ] && return 0
-
- case "$ftype" in
- "file")
- str="$ftype $name $location $str"
- ;;
- "nod")
- local devtype=
- local maj=$(LC_ALL=C ls -l "$location" | \
- awk '{sub(/,/, "", $5); print $5}')
- local min=$(LC_ALL=C ls -l "$location" | \
- awk '{print $6}')
-
- if [ -b "$location" ]; then
- devtype="b"
- else
- devtype="c"
- fi
- str="$ftype $name $str $devtype $maj $min"
- ;;
- "slink")
- local target=$(LC_ALL=C ls -l "$location" | \
- awk '{print $11}')
- str="$ftype $name $target $str"
- ;;
- *)
- str="$ftype $name $str"
- ;;
- esac
-
- echo "$str"
-
- return 0
-}
-
-usage() {
- printf "Usage:\n"
- printf "$0 [ [-u <root_uid>] [-g <root_gid>] [-d | <cpio_source>] ] . . .\n"
- printf "\n"
- printf -- "-u <root_uid> User ID to map to user ID 0 (root).\n"
- printf " <root_uid> is only meaningful if <cpio_source>\n"
- printf " is a directory.\n"
- printf -- "-g <root_gid> Group ID to map to group ID 0 (root).\n"
- printf " <root_gid> is only meaningful if <cpio_source>\n"
- printf " is a directory.\n"
- printf "<cpio_source> File list or directory for cpio archive.\n"
- printf " If <cpio_source> is not provided then a\n"
- printf " a default list will be output.\n"
- printf -- "-d Output the default cpio list. If no <cpio_source>\n"
- printf " is given then the default cpio list will be output.\n"
- printf "\n"
- printf "All options may be repeated and are interpreted sequentially\n"
- printf "and immediately. -u and -g states are preserved across\n"
- printf "<cpio_source> options so an explicit \"-u 0 -g 0\" is required\n"
- printf "to reset the root/group mapping.\n"
-}
-
-build_list() {
- printf "\n#####################\n# $cpio_source\n"
-
- if [ -f "$cpio_source" ]; then
- print_mtime "$cpio_source"
- cat "$cpio_source"
- elif [ -d "$cpio_source" ]; then
- srcdir=$(echo "$cpio_source" | sed -e 's://*:/:g;s:/$::')
- dirlist=$(find "$srcdir" -printf "%p %m %U %G\n" 2>/dev/null)
-
- # If $dirlist is only one line, then the directory is empty
- if [ "$(echo "$dirlist" | wc -l)" -gt 1 ]; then
- print_mtime "$cpio_source"
-
- echo "$dirlist" | \
- while read x; do
- parse $x
- done
- else
- # Failsafe in case directory is empty
- default_initramfs
- fi
- else
- echo " $0: Cannot open '$cpio_source'" >&2
- exit 1
- fi
-}
-
-
-root_uid=0
-root_gid=0
-
-while [ $# -gt 0 ]; do
- arg="$1"
- shift
- case "$arg" in
- "-u")
- root_uid="$1"
- shift
- ;;
- "-g")
- root_gid="$1"
- shift
- ;;
- "-d")
- default_list="$arg"
- default_initramfs
- ;;
- "-h")
- usage
- exit 0
- ;;
- *)
- case "$arg" in
- "-"*)
- printf "ERROR: unknown option \"$arg\"\n" >&2
- printf "If the filename validly begins with '-', then it must be prefixed\n" >&2
- printf "by './' so that it won't be interpreted as an option." >&2
- printf "\n" >&2
- usage >&2
- exit 1
- ;;
- *)
- cpio_source="$arg"
- build_list
- ;;
- esac
- ;;
- esac
-done
-
-# spit out the default cpio list if a source hasn't been specified
-[ -z "$cpio_source" -a -z "$default_list" ] && default_initramfs
-
-exit 0
diff --git a/fs/initramfs/init b/fs/initramfs/init
deleted file mode 100755
index a275482..0000000
--- a/fs/initramfs/init
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/sh
-# devtmpfs does not get automounted for initramfs
-/bin/mount -t devtmpfs devtmpfs /dev
-exec 0</dev/console
-exec 1>/dev/console
-exec 2>/dev/console
-exec /sbin/init $*
diff --git a/fs/initramfs/initramfs.mk b/fs/initramfs/initramfs.mk
index 1cd48b6..f1eb8b6 100644
--- a/fs/initramfs/initramfs.mk
+++ b/fs/initramfs/initramfs.mk
@@ -1,36 +1,23 @@
#############################################################
#
-# Make a initramfs_list file to be used by gen_init_cpio
-# gen_init_cpio is part of the 2.6 linux kernels to build an
-# initial ramdisk filesystem based on cpio
+# Build a kernel with an integrated initial ramdisk
+# filesystem based on cpio.
#
#############################################################
-ifeq ($(BR2_ROOTFS_DEVICE_CREATION_STATIC),y)
+ROOTFS_INITRAMFS_DEPENDENCIES += rootfs-cpio
-define ROOTFS_INITRAMFS_ADD_INIT
- if [ ! -e $(TARGET_DIR)/init ]; then \
- ln -sf sbin/init $(TARGET_DIR)/init; \
- fi
-endef
+ROOTFS_INITRAMFS_POST_TARGETS += linux26-rebuild-with-initramfs
-else
-# devtmpfs does not get automounted when initramfs is used.
-# Add a pre-init script to mount it before running init
-define ROOTFS_INITRAMFS_ADD_INIT
- if [ ! -e $(TARGET_DIR)/init ]; then \
- $(INSTALL) -m 0755 fs/initramfs/init $(TARGET_DIR)/init; \
- fi
-endef
-endif # BR2_ROOTFS_DEVICE_CREATION_STATIC
+# The generic fs infrastructure isn't very useful here.
-ROOTFS_INITRAMFS_PRE_GEN_HOOKS += ROOTFS_INITRAMFS_ADD_INIT
+rootfs-initramfs: $(ROOTFS_INITRAMFS_DEPENDENCIES) $(ROOTFS_INITRAMFS_POST_TARGETS)
-define ROOTFS_INITRAMFS_CMD
- $(SHELL) fs/initramfs/gen_initramfs_list.sh -u 0 -g 0 $(TARGET_DIR) > $$@
-endef
+rootfs-initramfs-show-depends:
+ @echo $(ROOTFS_INITRAMFS_DEPENDENCIES)
-ROOTFS_INITRAMFS_POST_TARGETS += linux26-rebuild-with-initramfs
+ifeq ($(BR2_TARGET_ROOTFS_INITRAMFS),y)
+TARGETS += rootfs-initramfs
+endif
-$(eval $(call ROOTFS_TARGET,initramfs))
diff --git a/linux/linux.mk b/linux/linux.mk
index f249d96..600b14d 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -126,13 +126,13 @@ define LINUX_CONFIGURE_CMDS
$(call KCONFIG_ENABLE_OPT,CONFIG_AEABI,$(@D)/.config),
$(call KCONFIG_DISABLE_OPT,CONFIG_AEABI,$(@D)/.config))
# As the kernel gets compiled before root filesystems are
- # built, we create a fake initramfs file list. It'll be
- # replaced later by the real list, and the kernel will be
+ # built, we create a fake cpio file. It'll be
+ # replaced later by the real cpio archive, and the kernel will be
# rebuilt using the linux26-rebuild-with-initramfs target.
$(if $(BR2_TARGET_ROOTFS_INITRAMFS),
- touch $(BINARIES_DIR)/rootfs.initramfs
+ touch $(BINARIES_DIR)/rootfs.cpio
$(call KCONFIG_ENABLE_OPT,CONFIG_BLK_DEV_INITRD,$(@D)/.config)
- $(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,\"$(BINARIES_DIR)/rootfs.initramfs\",$(@D)/.config)
+ $(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_SOURCE,\"$(BINARIES_DIR)/rootfs.cpio\",$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_UID,0,$(@D)/.config)
$(call KCONFIG_SET_OPT,CONFIG_INITRAMFS_ROOT_GID,0,$(@D)/.config)
$(call KCONFIG_DISABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_NONE,$(@D)/.config)
@@ -190,13 +190,10 @@ linux-savedefconfig linux26-savedefconfig: dirs $(LINUX_DIR)/.stamp_configured
$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) \
$(subst linux-,,$(subst linux26-,,$@))
-# Support for rebuilding the kernel after the initramfs file list has
-# been generated in $(BINARIES_DIR)/rootfs.initramfs.
-$(LINUX_DIR)/.stamp_initramfs_rebuilt: $(LINUX_DIR)/.stamp_target_installed $(LINUX_DIR)/.stamp_images_installed $(BINARIES_DIR)/rootfs.initramfs
+# Support for rebuilding the kernel after the cpio archive has
+# been generated in $(BINARIES_DIR)/rootfs.cpio.
+$(LINUX_DIR)/.stamp_initramfs_rebuilt: $(LINUX_DIR)/.stamp_target_installed $(LINUX_DIR)/.stamp_images_installed $(BINARIES_DIR)/rootfs.cpio
@$(call MESSAGE,"Rebuilding kernel with initramfs")
- # Remove the previously generated initramfs which was empty,
- # to make sure the kernel will actually regenerate it.
- $(RM) -f $(@D)/usr/initramfs_data.cpio*
# Build the kernel.
$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_IMAGE_NAME)
# Copy the kernel image to its final destination