source: branches/stable/mindi-busybox/docs/mdev.txt @ 1770

Last change on this file since 1770 was 1770, checked in by Bruno Cornec, 13 years ago
  • Better output for mindi-busybox revision
  • Remove dummy file created on NFS - report from Arnaud Tiger <arnaud.tiger_at_hp.com>
  • strace useful for debug
  • fix new versions for pb (2.0.0 for mindi and 1.7.2 for mindi-busybox)
  • fix build process for mindi-busybox + options used in that version (dd for label-partitions-as-necessary)
  • fix typo in label-partitions-as-necessary which doesn't seem to work
  • Update to busybox 1.7.2
  • perl is now required at restore time to support uuid swap partitions (and will be used for many other thigs

in the future for sure)

  • next mindi version will be 2.0.0 due to all the changes made in it (udev may break working distros)
  • small optimization in mindi on keyboard handling (one single find instead of multiple)
  • better interaction for USB device when launching mindi manually
  • attempt to automatically guess block disk size for ramdisk
  • fix typos in bkphw
  • Fix the remaining problem with UUID support for swap partitions
  • Updates mondoarchive man page for USB support
  • Adds preliminary Hardware support to mindi (Proliant SSSTK)
  • Tries to add udev support also for rhel4
  • Fix UUID support which was still broken.
  • Be conservative in test for the start-nfs script
  • Update config file for mindi-busybox for 1.7.2 migration
  • Try to run around a busybox bug (1.2.2 pb on inexistant links)
  • Add build content for mindi-busybox in pb
  • Remove distributions content for mindi-busybox
  • Fix a warning on inexistant raidtab
  • Solve problem on tmpfs in restore init (Problem of inexistant symlink and busybox)
  • Create MONDO_CACHE and use it everywhere + creation at start
  • Really never try to eject a USB device
  • Fix a issue with &> usage (replaced with 1> and 2>)
  • Adds magic file to depllist in order to have file working + ldd which helps for debugging issues
  • tty modes correct to avoid sh error messages
  • Use ext3 normally and not ext2 instead
  • USB device should be corrected after reading (take 1st part)
  • Adds a mount_USB_here function derived from mount_CDROM_here
  • usb detection place before /dev detection in device name at restore time
  • Fix when restoring from USB: media is asked in interactive mode
  • Adds USB support for mondorestore
  • mount_cdrom => mount_media
  • elilo.efi is now searched throughout /boot/efi and not in a fixed place as there is no standard
  • untar-and-softlink => untar (+ interface change)
  • suppress useless softlinks creation/removal in boot process
  • avoids udevd messages on groups
  • Increase # of disks to 99 as in mindi at restore time (should be a conf file parameter)
  • skip existing big file creation
  • seems to work correctly for USB mindi boot
  • Adds group and tty link to udev conf
  • Always load usb-torage (even 2.6) to initiate USB bus discovery
  • Better printing of messages
  • Attempt to fix a bug in supporting OpenSusE 10.3 kernel for initramfs (mindi may now use multiple regex for kernel initrd detection)
  • Links were not correctly done as non relative for modules in mindi
  • exclusion of modules denied now works
  • Also create modules in their ordinary place, so that classical modprobe works + copy modules.dep
  • Fix bugs for DENY_MODS handling
  • Add device /dev/console for udev
  • ide-generic should now really be excluded
  • Fix a bug in major number for tty
  • If udev then adds modprobe/insmod to rootfs
  • tty0 is also cretaed with udev
  • ide-generic put rather in DENY_MODS
  • udevd remove from deplist s handled in mindi directly
  • better default for mindi when using --usb
  • Handles dynamically linked busybox (in case we want to use it soon ;-)
  • Adds fixed devices to create for udev
  • ide-generic should not be part of the initrd when using libata v2
  • support a dynamically linked udev (case on Ubuntu 7.10 and Mandriva 2008.0 so should be quite generic) This will give incitation to move to dyn. linked binaries in the initrd which will help for other tasks (ia6 4)
  • Improvement in udev support (do not use cl options not available in busybox)
  • Udev in mindi
    • auto creation of the right links at boot time with udev-links.conf(from Mandriva 2008.0)
    • rework startup of udev as current makes kernel crash (from Mandriva 2008.0)
    • add support for 64 bits udev
  • Try to render MyInsmod? silent at boot time
  • Adds udev support (mandatory for newest distributions to avoid remapping of devices in a different way as on the original system)
  • We also need vaft format support for USB boot
  • Adds libusual support (Ubuntu 7.10 needs it for USB)
  • Improve Ubuntu/Debian? keyboard detection and support
  • pbinit adapted to new pb (0.8.10). Filtering of docs done in it
  • Suppress some mondo warnings and errors on USB again
  • Tries to fix lack of files in deb mindi package
  • Verify should now work for USB devices
  • More log/mesages improvement for USB support
  • - Supress g_erase_tmpdir_and_scratchdir
  • Improve some log messages for USB support
  • Try to improve install in mindi to avoid issues with isolinux.cfg not installed vene if in the pkg :-(
  • Improve mindi-busybox build
  • In conformity with pb 0.8.9
  • Add support for Ubuntu 7.10 in build process
  • Add USB Key button to Menu UI (CD streamer removed)
  • Attempt to fix error messages on tmp/scratch files at the end by removing those dir at the latest possible.
  • Fix a bug linked to the size of the -E param which could be used (Arnaud Tiger/René? Ribaud).
  • Integrate ~/.pbrc content into mondorescue.pb (required project-builder >= 0.8.7)
  • Put mondorescue in conformity with new pb filtering rules
  • Add USB support at restore time (no test done yet). New start-usb script PB varibale added where useful
  • Unmounting USB device before removal of temporary scratchdir
  • Stil refining USB copy back to mondo (one command was not executed)
  • No need to have the image subdor in the csratchdir when USB.
  • umount the USB partition before attempting to use it
  • Remove useless copy from mindi to mondo at end of USB handling

(risky merge, we are raising the limits of 2 diverging branches. The status of stable is not completely sure as such. Will need lots of tests, but it's not yet done :-()
(merge -r1692:1769 $SVN_M/branches/2.2.5)

  • Property svn:eol-style set to native
File size: 3.0 KB
Line 
1-------------
2 MDEV Primer
3-------------
4
5For those of us who know how to use mdev, a primer might seem lame.  For
6everyone else, mdev is a weird black box that they hear is awesome, but can't
7seem to get their head around how it works.  Thus, a primer.
8
9-----------
10 Basic Use
11-----------
12
13Mdev has two primary uses: initial population and dynamic updates.  Both
14require sysfs support in the kernel and have it mounted at /sys.  For dynamic
15updates, you also need to have hotplugging enabled in your kernel.
16
17Here's a typical code snippet from the init script:
18[1] mount -t sysfs sysfs /sys
19[2] echo /bin/mdev > /proc/sys/kernel/hotplug
20[3] mdev -s
21
22Of course, a more "full" setup would entail executing this before the previous
23code snippet:
24[4] mount -t tmpfs mdev /dev
25[5] mkdir /dev/pts
26[6] mount -t devpts devpts /dev/pts
27
28The simple explanation here is that [1] you need to have /sys mounted before
29executing mdev.  Then you [2] instruct the kernel to execute /bin/mdev whenever
30a device is added or removed so that the device node can be created or
31destroyed.  Then you [3] seed /dev with all the device nodes that were created
32while the system was booting.
33
34For the "full" setup, you want to [4] make sure /dev is a tmpfs filesystem
35(assuming you're running out of flash).  Then you want to [5] create the
36/dev/pts mount point and finally [6] mount the devpts filesystem on it.
37
38-------------
39 MDEV Config   (/etc/mdev.conf)
40-------------
41
42Mdev has an optional config file for controlling ownership/permissions of
43device nodes if your system needs something more than the default root/root
44660 permissions.
45
46The file has the format:
47    <device regex> <uid>:<gid> <octal permissions>
48For example:
49    hd[a-z][0-9]* 0:3 660
50
51The config file parsing stops at the first matching line.  If no line is
52matched, then the default of 0:0 660 is used.  To set your own default, simply
53create your own total match like so:
54    .* 1:1 777
55
56If you also enable support for executing your own commands, then the file has
57the format:
58    <device regex> <uid>:<gid> <octal permissions> [<@|$|*> <command>]
59The special characters have the meaning:
60    @ Run after creating the device.
61    $ Run before removing the device.
62    * Run both after creating and before removing the device.
63
64The command is executed via the system() function (which means you're giving a
65command to the shell), so make sure you have a shell installed at /bin/sh.
66
67For your convenience, the shell env var $MDEV is set to the device name.  So if
68the device 'hdc' was matched, MDEV would be set to "hdc".
69
70----------
71 FIRMWARE
72----------
73
74Some kernel device drivers need to request firmware at runtime in order to
75properly initialize a device.  Place all such firmware files into the
76/lib/firmware/ directory.  At runtime, the kernel will invoke mdev with the
77filename of the firmware which mdev will load out of /lib/firmware/ and into
78the kernel via the sysfs interface.  The exact filename is hardcoded in the
79kernel, so look there if you need to want to know what to name the file in
80userspace.
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