Create menu entry to select device creation method
PATCH v2 1/3 Create menu entry to select device creation method
Hello Thomas and Yann,
I've added a detailed help for device creation options. With the matter being described I think we can leave mdev starting script and kernel side mdev hotplugging activation as is.
Best regards,
Yegor
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From: Yegor Yefremov <[email protected]>
Four methods for the creation of device files in /dev are now proposed:
- static method uses device table as before
- devtmpfs method enables this feature in kernel
- mdev method adds mdev starting script to the file system and selects mdev itself for installation
- udev method selects udev for installation
All dynamic methods are based on devtmpfs, so one doesn't need to care about /dev folder.
Signed-off-by Yegor Yefremov <[email protected]>
Signed-off-by Thomas Petazzoni <[email protected]>
--- fs/Config.in | 33 +++++++++++++++++++++++++++------ linux/linux.mk | 7 +++++++ package/busybox/S10mdev | 22 ++++++++++++++++++++++ package/busybox/busybox.mk | 15 +++++++++++++++ 4 files changed, 71 insertions(+), 6 deletions(-) create mode 100644 package/busybox/S10mdev
fs/Config.in +46 -6
@@ -15,13 +15,53 @@ only argument. Make sure the exit code of that script is 0, otherwise make will stop after calling it. +choice + prompt "/dev management" + default BR2_ROOTFS_DEVICE_CREATION_STATIC + +config BR2_ROOTFS_DEVICE_CREATION_STATIC + bool "Static using device table" + help + Use a device table, that will be passed to the makedevs utility + to create all the special device files in the target filesystem. + +config BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS + bool "Dynamic using devtmpfs only" + help + Enable CONFIG_DEVTMPFS and CONFIG_DEVTMPFS_MOUNT kernel options + to create and mount /dev before userspace starts. All registered + devices will occur in /dev directory. + +config BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV + bool "Dynamic using mdev" + select BR2_PACKAGE_BUSYBOX + help + Use mdev to populate /dev directory and load firmware. + For the latter special kernel option CONFIG_UEVENT_HELPER_PATH + will be set to mdev. + + CONFIG_DEVTMPFS and CONFIG_DEVTMPFS_MOUNT kernel options will be + also enabled to dynamically create and mount /dev directory. + +config BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_UDEV + bool "Dynamic using udev" + select BR2_PACKAGE_UDEV + help + Use udev to populate /dev directory and load firmware. + + CONFIG_DEVTMPFS and CONFIG_DEVTMPFS_MOUNT kernel options will be + also enabled to dynamically create and mount /dev directory. + +endchoice + config BR2_ROOTFS_DEVICE_TABLE - string "Path to the device table" - default "target/generic/device_table.txt" - help - Specify the location of a device table, that will be passed - to the makedevs utility to create all the special device - files in the target filesystem. + string "Path to the device table" + depends on BR2_ROOTFS_DEVICE_CREATION_STATIC + default "target/generic/device_table.txt" + help + Specify the location of a device table, that will be passed + to the makedevs utility to create all the special device + files in the target filesystem. choice prompt "Root FS skeleton"
linux/linux.mk +7 -0
@@ -130,6 +130,13 @@ $(call KCONFIG_DISABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_NONE,$(@D)/.config) $(call KCONFIG_ENABLE_OPT,CONFIG_INITRAMFS_COMPRESSION_GZIP,$(@D)/.config) endif +ifneq ($(BR2_ROOTFS_DEVICE_CREATION_STATIC),y) + $(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS,$(@D)/.config) + $(call KCONFIG_ENABLE_OPT,CONFIG_DEVTMPFS_MOUNT,$(@D)/.config) +endif +ifeq ($(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV),y) + $(call KCONFIG_SET_OPT,CONFIG_UEVENT_HELPER_PATH,\"/sbin/mdev\",$(@D)/.config) +endif $(TARGET_MAKE_ENV) $(MAKE) $(LINUX26_MAKE_FLAGS) -C $(@D) oldconfig $(Q)touch $@
package/busybox/S10mdev new file +22 -0
@@ -0,0 +1,22 @@ +#!/bin/sh +# +# Start mdev.... +# + +case "$1" in + start) + echo "Starting mdev..." + /sbin/mdev -s + ;; + stop) + ;; + restart|reload) + ;; + *) + echo $"Usage: $0 {start|stop|restart}" + exit 1 +esac + +exit $? + +
package/busybox/busybox.mk +15 -0
@@ -28,6 +28,19 @@ BUSYBOX_CONFIG_FILE = $(call qstrip,$(BR2_PACKAGE_BUSYBOX_CONFIG)) endif +# If mdev will be used for device creation enable it and copy S10mdev to /etc/init.d +ifeq ($(BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_MDEV),y) +define BUSYBOX_INSTALL_MDEV_SCRIPT + install -m 0755 package/busybox/S10mdev $(TARGET_DIR)/etc/init.d +endef +define BUSYBOX_SET_MDEV + $(call KCONFIG_ENABLE_OPT,CONFIG_MDEV,$(BUSYBOX_BUILD_CONFIG)) + $(call KCONFIG_ENABLE_OPT,CONFIG_FEATURE_MDEV_CONF,$(BUSYBOX_BUILD_CONFIG)) + $(call KCONFIG_ENABLE_OPT,CONFIG_FEATURE_MDEV_EXEC,$(BUSYBOX_BUILD_CONFIG)) + $(call KCONFIG_ENABLE_OPT,CONFIG_FEATURE_MDEV_LOAD_FIRMWARE,$(BUSYBOX_BUILD_CONFIG)) +endef +endif + # If we have external syslogd, force busybox to use it ifeq ($(BR2_PACKAGE_SYSKLOGD),y) define BUSYBOX_SET_SYSKLOGD
@@ -122,6 +135,7 @@ $(BUSYBOX_SET_IPV6) $(BUSYBOX_SET_RPC) $(BUSYBOX_PREFER_STATIC) + $(BUSYBOX_SET_MDEV) $(BUSYBOX_NETKITBASE) $(BUSYBOX_NETKITTELNET) @yes "" | $(MAKE) ARCH=$(KERNEL_ARCH) CROSS_COMPILE="$(TARGET_CROSS)" \
@@ -138,6 +152,7 @@ $(INSTALL) -m 0755 -D package/busybox/udhcpc.script \ $(TARGET_DIR)/usr/share/udhcpc/default.script; \ fi + $(BUSYBOX_INSTALL_MDEV_SCRIPT) endef define BUSYBOX_UNINSTALL_TARGET_CMDS