diff options
Diffstat (limited to 'drivers/base/Kconfig')
| -rw-r--r-- | drivers/base/Kconfig | 51 |
1 files changed, 33 insertions, 18 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index ee377270beb..fd52c48ee76 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -3,35 +3,50 @@ menu "Generic Driver Options" config UEVENT_HELPER_PATH string "path to uevent helper" depends on HOTPLUG - default "/sbin/hotplug" + default "" help Path to uevent helper program forked by the kernel for every uevent. + Before the switch to the netlink-based uevent source, this was + used to hook hotplug scripts into kernel device events. It + usually pointed to a shell script at /sbin/hotplug. + This should not be used today, because usual systems create + many events at bootup or device discovery in a very short time + frame. One forked process per event can create so many processes + that it creates a high system load, or on smaller systems + it is known to create out-of-memory situations during bootup. config DEVTMPFS - bool "Create a kernel maintained /dev tmpfs (EXPERIMENTAL)" + bool "Maintain a devtmpfs filesystem to mount at /dev" depends on HOTPLUG && SHMEM && TMPFS help - This creates a tmpfs filesystem, and mounts it at bootup - and mounts it at /dev. The kernel driver core creates device - nodes for all registered devices in that filesystem. All device - nodes are owned by root and have the default mode of 0600. - Userspace can add and delete the nodes as needed. This is - intended to simplify bootup, and make it possible to delay - the initial coldplug at bootup done by udev in userspace. - It should also provide a simpler way for rescue systems - to bring up a kernel with dynamic major/minor numbers. - Meaningful symlinks, permissions and device ownership must - still be handled by userspace. - If unsure, say N here. + This creates a tmpfs filesystem instance early at bootup. + In this filesystem, the kernel driver core maintains device + nodes with their default names and permissions for all + registered devices with an assigned major/minor number. + Userspace can modify the filesystem content as needed, add + symlinks, and apply needed permissions. + It provides a fully functional /dev directory, where usually + udev runs on top, managing permissions and adding meaningful + symlinks. + In very limited environments, it may provide a sufficient + functional /dev without any further help. It also allows simple + rescue systems, and reliably handles dynamic major/minor numbers. config DEVTMPFS_MOUNT - bool "Automount devtmpfs at /dev" + bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs" depends on DEVTMPFS help - This will mount devtmpfs at /dev if the kernel mounts the root - filesystem. It will not affect initramfs based mounting. - If unsure, say N here. + This will instruct the kernel to automatically mount the + devtmpfs filesystem at /dev, directly after the kernel has + mounted the root filesystem. The behavior can be overridden + with the commandline parameter: devtmpfs.mount=0|1. + This option does not affect initramfs based booting, here + the devtmpfs filesystem always needs to be mounted manually + after the roots is mounted. + With this option enabled, it allows to bring up a system in + rescue mode with init=/bin/sh, even when the /dev directory + on the rootfs is completely empty. config STANDALONE bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL |