UdevRoadmap

Differences between revisions 5 and 6
Revision 5 as of 2005-11-03 16:30:23
Size: 2238
Editor: 209
Comment:
Revision 6 as of 2005-11-03 16:42:17
Size: 2129
Editor: 209
Comment:
Deletions are marked like this. Additions are marked like this.
Line 32: Line 32:
Line 36: Line 37:
 * Touch /dev/.udev_scoreboard
Line 50: Line 50:
 * Add scoreboard to udevd  * Implement scroreboard from HardwareActivation
 * Implement udevplug from HardwareActivation
Line 55: Line 56:

=== Code ===

The scoreboading component will need to be written.
initramfs-tools needs to be modified to handle event driven coldplugging.

Summary

Upgrading from udev 060 to 071 is a major change that affects initramfs, udev, hotplug, hal, and many other pieces. The 2.6.15 kernel will require udev 071. Because these changes are invasive, this spec is split out from HardwareDetection to make sure that it can be reviewed and implemented independantly.

Rationale

Scope

Newer versions of udev affect the following packages:

  • initramfs-tools
  • hotplug
  • klibc
  • hal
  • linux-image-*

Implementation

initramfs

Update the initramfs startup sequence to reflect the following:

  • Create base device nodes
  • Start udevd
  • Load modules from /etc/mkinitramfs/modules (and other force_load calls)

Note: without udevstart, something needs to correct permissions, or we need to provide the rules.

  • Walk the sysfs tree for harddrive devices and tickle uevents for those
  • Walk the ide, scsi, and i2o busses
  • Attempt hibernate recovery
  • Walk the pci sysfs tree for usb controllers

udev

full userspace init scripts

  • Where udevstart and coldplugging routines are currently run, ensure that udevd is running (in case of custom kernels), and pass over entire sysfs tree to cause events to be rerun. This will ensure that device nodes are created with correct permissions and according to the rules of the running system.

Data preservation and migration

Custom written hotplug rules will need to be migrated to be udev rules. There is no way to do this in an automated fashion.

Outstanding issues

UdevRoadmap (last edited 2008-08-06 16:16:48 by localhost)