[OE-core] [PATCH 1/5] initramfs-base: provides the base for a modular initramfs
Otavio Salvador
otavio at ossystems.com.br
Tue Dec 6 16:07:27 UTC 2011
Provides the API to be used by the initramfs module. The modules need
to provide the following functions:
<module>_enabled : check if the module ought to run (return 1 to skip)
<module>_run : do what is need
Boot parameters are available on environment in the as:
'foo=value' as 'bootparam_foo=value'
'foo' as 'bootparam_foo=true'
Another possibility is to add hooks to be run before and/or after a
module to be run, allowing for fancy features as dynamic debug shells
and like.
Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
---
.../initrdscripts/initramfs-base/finish | 42 ++++++
.../recipes-core/initrdscripts/initramfs-base/init | 136 ++++++++++++++++++++
.../initrdscripts/initramfs-base_1.0.bb | 17 +++
3 files changed, 195 insertions(+), 0 deletions(-)
create mode 100755 meta/recipes-core/initrdscripts/initramfs-base/finish
create mode 100755 meta/recipes-core/initrdscripts/initramfs-base/init
create mode 100644 meta/recipes-core/initrdscripts/initramfs-base_1.0.bb
diff --git a/meta/recipes-core/initrdscripts/initramfs-base/finish b/meta/recipes-core/initrdscripts/initramfs-base/finish
new file mode 100755
index 0000000..8139b42
--- /dev/null
+++ b/meta/recipes-core/initrdscripts/initramfs-base/finish
@@ -0,0 +1,42 @@
+#!/bin/sh
+# Copyright (C) 2011 O.S. Systems Software LTDA.
+# Licensed on MIT
+
+finish_enabled() {
+ return 0
+}
+
+finish_run() {
+ if [ -n "$ROOTFS_DIR" ]; then
+ if [ -n "$bootparam_rootdelay" ]; then
+ debug "Sleeping for $rootdelay second(s) to wait root to settle..."
+ sleep $bootparam_rootdelay
+ fi
+
+ if [ -n "$bootparam_root" ]; then
+ debug "No e2fs compatible filesystem has been mounted, mounting $bootparam_root..."
+
+ if [ -e "$bootparam_root" ]; then
+ mount $bootparam_root $ROOTFS_DIR
+ else
+ debug "root '$bootparam_root' doesn't exist."
+ fi
+ fi
+
+ if [ ! -d $ROOTFS_DIR/dev ]; then
+ fatal "ERROR: There's no '/dev' on rootfs."
+ fi
+
+ info "Switching root to '$ROOTFS_DIR'..."
+
+ debug "Moving /dev, /proc and /sys onto rootfs..."
+ mount --move /dev $ROOTFS_DIR/dev
+ mount --move /proc $ROOTFS_DIR/proc
+ mount --move /sys $ROOTFS_DIR/sys
+
+ cd $ROOTFS_DIR
+ exec switch_root -c /dev/console $ROOTFS_DIR /sbin/init
+ else
+ debug "No rootfs has been set"
+ fi
+}
diff --git a/meta/recipes-core/initrdscripts/initramfs-base/init b/meta/recipes-core/initrdscripts/initramfs-base/init
new file mode 100755
index 0000000..fc4b0db
--- /dev/null
+++ b/meta/recipes-core/initrdscripts/initramfs-base/init
@@ -0,0 +1,136 @@
+#!/bin/sh
+# Copyright (C) 2011 O.S. Systems Software LTDA.
+# Licensed on MIT
+#
+# Provides the API to be used by the initramfs modules
+#
+# Modules need to provide the following functions:
+#
+# <module>_enabled : check if the module ought to run (return 1 to skip)
+# <module>_run : do what is need
+#
+# Boot parameters are available on environment in the as:
+#
+# 'foo=value' as 'bootparam_foo=value'
+# 'foo' as 'bootparam_foo=true'
+
+# Register a function to be called before running a module
+# The hook is called as:
+# <function> pre <module>
+add_module_pre_hook() {
+ MODULE_PRE_HOOKS="$MODULE_PRE_HOOKS $1"
+}
+
+# Register a function to be called after running a module
+# The hook is called as:
+# <function> post <module>
+add_module_post_hook() {
+ MODULE_POST_HOOKS="$MODULE_POST_HOOKS $1"
+}
+
+# Load kernel module
+load_kernel_module() {
+ if modprobe $1 >/dev/null 2>&1; then
+ info "Loaded module $1"
+ else
+ debug "Failed to load module $1"
+ fi
+}
+
+# Prints information
+msg() {
+ echo "$@" >/dev/console
+}
+
+# Prints information if verbose bootparam is used
+info() {
+ [ -n "$bootparam_verbose" ] && echo "$@" >/dev/console
+}
+
+# Prints information if debug bootparam is used
+debug() {
+ [ -n "$bootparam_debug" ] && echo "DEBUG: $@" >/dev/console
+}
+
+# Prints a message and start a endless loop
+fatal() {
+ echo $1 >/dev/console
+ echo >/dev/console
+
+ while [ "true" ]; do
+ sleep 3600
+ done
+}
+
+# Variables shared amoung modules
+ROOTFS_DIR="/rootfs" # where to do the switch root
+MODULE_PRE_HOOKS="" # functions to call before running each module
+MODULE_POST_HOOKS="" # functions to call after running each module
+MODULES_DIR=/init.d # place to look for modules
+
+# initialize /proc and /sys
+mkdir -p /proc /sys
+mount -t proc proc /proc
+mount -t sysfs sysfs /sys
+
+# populate bootparam environment
+for p in `cat /proc/cmdline`; do
+ opt="${p%%=*}"
+ opt=${opt/-/_}
+ if [ "${p/=/}" = "$p" ]; then
+ eval "bootparam_${opt}=true"
+ else
+ eval "bootparam_${opt}=\"${p#*=}\""
+ fi
+done
+
+# use /dev with devtmpfs
+if grep -q devtmpfs /proc/filesystems; then
+ mkdir -p /dev
+ mount -t devtmpfs devtmpfs /dev
+else
+ if [ ! -d /dev ]; then
+ fatal "ERROR: /dev doesn't exist and kernel doesn't has devtmpfs enabled."
+ fi
+fi
+
+mkdir $ROOTFS_DIR
+
+# Load and run modules
+for m in $MODULES_DIR/*; do
+ # Skip backup files
+ if [ "${m/\~/}" != "$m" ]; then
+ continue
+ fi
+
+ module=`basename $m | cut -d'-' -f 2`
+ debug "Loading module $module"
+
+ # pre hooks
+ for h in $MODULE_PRE_HOOKS; do
+ debug "Calling module hook (pre): $h"
+ eval "$h pre $module"
+ debug "Finished module hook (pre): $h"
+ done
+
+ # process module
+ source $m
+
+ if ! eval "${module}_enabled"; then
+ debug "Skipping module $module"
+ continue
+ fi
+
+ debug "Running ${module}_run"
+ eval "${module}_run"
+
+ # post hooks
+ for h in $MODULE_POST_HOOKS; do
+ debug "Calling module hook (post): $h"
+ eval "$h post $module"
+ debug "Finished module hook (post): $h"
+ done
+done
+
+# Catch all
+fatal "ERROR: Initramfs failed to initialize the system."
diff --git a/meta/recipes-core/initrdscripts/initramfs-base_1.0.bb b/meta/recipes-core/initrdscripts/initramfs-base_1.0.bb
new file mode 100644
index 0000000..e98e0f5
--- /dev/null
+++ b/meta/recipes-core/initrdscripts/initramfs-base_1.0.bb
@@ -0,0 +1,17 @@
+DESCRIPTION = "initramfs modular system base"
+LICENSE = "MIT"
+LIC_FILES_CHKSUM = "file://${COREBASE}/meta/COPYING.MIT;md5=3da9cfbcb788c80a0384361b4de20420"
+RDEPENDS = "busybox"
+
+inherit allarch
+
+SRC_URI = "file://init \
+ file://finish"
+
+do_install() {
+ install -d ${D}/init.d
+ install -m 0755 ${WORKDIR}/init ${D}/init
+ install -m 0755 ${WORKDIR}/finish ${D}/init.d/99-finish
+}
+
+FILES_${PN} = "/init /init.d/*"
--
1.7.2.5
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