diff --git a/chapter01/changelog.xml b/chapter01/changelog.xml
index 4cddeb7cd..cf55f3297 100644
--- a/chapter01/changelog.xml
+++ b/chapter01/changelog.xml
@@ -36,6 +36,15 @@
-->
+
+ April 13, 2006
+
+
+ [archaic] - Merged the udev_update branch to trunk.
+
+
+
+
April 12, 2006
@@ -43,9 +52,6 @@
[jhuntwork] - Rewrote section explaining IP Addresses.
Thanks Bryan Kadzban and Bruce Dubbs. Resolves Ticket 1663.
-
- [jhuntwork] - Adjust some redundant text in Berkeley DB page.
-
[jhuntwork] - Added a pointer to GDBM in Berkeley DB page.
Also added explanatory text concerning why LFS chose Debian's
@@ -69,6 +75,19 @@
+
+ April 8, 2006
+
+
+ [jhuntwork] - Added a command to create an empty /etc/mtab file early
+ in chapter 6. This avoids testsuite failures in e2fsprogs and possibly other
+ programs that expect /etc/mtab to be present. Explanation from Dan Nicholson,
+ slightly modified. Also merged the 'Creating Essential Symlinks' section with
+ 'Creating passwd, group and log Files'.
+
+
+
+
April 6, 2006
@@ -82,12 +101,31 @@
+
+ April 2, 2006
+
+
+ [archaic] - Moved the chowning of /tools to the end of chapter 5
+ and rewrote note about backing up or re-using /tools. Moved the
+ mounting of kernel filesystems before pkgmgt page and rewrote the page
+ to mount --bind /dev and mount all other kernel filesystems while
+ outside chroot. Rewrote note about re-entering chroot and remounting
+ kernel filesystems. Removed /dev from the list of dirs created in
+ chroot and added it before chroot.
+
+
+
+
March 30, 2006
[ken] - Correct my erroneous comment about UTF-8 locales in
- Man-DB. Thanks to Alexander for explaining it.
+ Man-DB. Thanks to Alexander for explaining it.
+
+
+ [ken] - upgraded to Linux-2.6.16.1, Iproute2-2.6.16-060323,
+ and Udev-088.
@@ -97,20 +135,33 @@
[ken] - Upgrade to shadow-4.0.15 and add convert-mans script
- to convert its UTF-8 man pages. Thanks to Alexander and Archaic for
- the script and commands. Fixes tickets #1748 and #1750.
+ to convert its UTF-8 man pages. Thanks to Alexander and Archaic for
+ the script and commands. Fixes tickets #1748 and #1750.
- March 22, 2006
-
-
- [archaic] - Updated to lfs-bootscripts-20060321.
-
-
-
+ March 22, 2006
+
+
+ [archaic] - Updated to
+ lfs-bootscripts-udev_update-20060321.
+
+
+
+
+
+ March 21, 2006
+
+
+ [archaic] - Updated the bootscripts. Removed references to
+ hotplug and the bootscripts udev patch. Removed reference to
+ udevstart. Added text and commands for generating Udev bug reports.
+
+
+
+
March 18, 2006
@@ -163,12 +214,32 @@
[matthew] - Upgrade to Man-pages 2.25.
+
+ [matthew] - Remove an example of poor Udev support as it
+ does not apply to the kernel used in the book. Thanks to Alexander
+ Patrakov.
+
+
+ [matthew] - Upgrade to Linux 2.6.15.6.
+
+
+ [matthew] - Upgrade to udev-087.
+
+
+ [matthew] - Udev's run_program rules require a null device to be
+ present at an early stage, so create one in /lib/udev/devices.
+
March 7, 2006
+
+ [matthew] - Update Udev rules file to load SCSI modules and
+ upload firmware to devices that need it. Improve explanations of
+ device and module handling. Thanks to Alexander Patrakov.
+
[archaic] - Replaced the debian-specific groff patch with an
LFS-style patch.
@@ -189,6 +260,10 @@
March 1, 2006
+
+ [archaic] - Create the Udev directories before creating the
+ symlinks.
+
[jhuntwork] - Added a description of perl configure flags that
help perl deal with a lack of groff. Thanks Dan Nicholson.
@@ -209,6 +284,11 @@
February 20, 2006
+
+ [matthew] - Use non-deprecated format for accessing MODALIAS
+ keys in the Udev rules file, and prevent the "$" from being
+ expanded by the shell.
+
[matthew] - Add patches 009 and 010 from Bash upstream.
@@ -225,6 +305,16 @@
[matthew] - Upgrade Perl libc patch to prevent Perl from trying
to find headers on the host system. Fixes bug 1695.
+
+ [matthew] - Expand the Udev module handling rule to run for
+ every subsystem, not just USB.
+
+
+ [matthew] - Upgrade to Linux 2.6.15.4.
+
+
+ [matthew] - Upgrade to Udev 085.
+
[matthew] - Install Sed's HTML documentation by using
--enable-html instead of editing the Makefile. Thanks to Greg Schafer
@@ -256,6 +346,13 @@
[matthew] - Add the verbose parameter to a couple of commands in
Linux-Libc-Headers and DB.
+
+ [matthew] - Create udev specific directories in udev's
+ instructions instead of the more generic creatingdirs.xml. Add
+ "pts" and "shm" directories to
+ /lib/udev/devices so that they
+ can be mounted successfully at boot time.
+
@@ -269,6 +366,62 @@
+
+ February 8, 2006
+
+
+ [matthew] - Rewrite the majority of chapter07/udev.xml to
+ reflect the new configuration for handling dynamic device naming and
+ module loading.
+
+
+
+
+
+ February 3, 2006
+
+
+ [matthew] - Create the
+ /lib/firmware directory that
+ can be used by Udev's firmware_helper utility.
+
+
+
+ [matthew] - Add descriptions of Udev's helper binaries.
+
+
+ [manuel] - Add udev bootscript patch to whatsnew. Removed
+ hotplug from list of packages to download.
+
+
+ [ken] - Add udev bootscript patch to list of patches to
+ download.
+
+
+ [ken] - Correct the size of the udev tarball.
+
+
+
+
+
+ February 2, 2006
+
+
+ [matthew] - Upgrade to Udev-084 and build all its extras to
+ enable custom rules to be written more easily. Also, change the
+ rules file to handle kernel module loading and patch the udev
+ bootscript to work with this version of udev.
+
+
+ [matthew] - Remove the hotplug package and related bootscript
+ Udev will now handle device creation and module loading.
+
+
+ [matthew] - Upgrade to Linux-2.6.15.2.
+
+
+
+
January 30, 2006
diff --git a/chapter01/whatsnew.xml b/chapter01/whatsnew.xml
index 9f4e0d79e..f3054097f 100644
--- a/chapter01/whatsnew.xml
+++ b/chapter01/whatsnew.xml
@@ -91,18 +91,15 @@
-
IANA-Etc &iana-etc-version;
-
+
@@ -269,6 +266,9 @@
glibc-2.3.4-fix_test-1.patch
+
+ hotplug-2004-09-23
+
inetutils-1.4.2-kernel_headers-1.patch
diff --git a/chapter03/packages.xml b/chapter03/packages.xml
index da1489765..8fe04e4fb 100644
--- a/chapter03/packages.xml
+++ b/chapter03/packages.xml
@@ -242,14 +242,6 @@
-
- Hotplug (&hotplug-version;) - 40 KB:
-
- Download:
-
-
-
Iana-Etc (&iana-etc-version;) - 174 KB:
@@ -270,7 +262,7 @@
- IPRoute2 (&iproute2-version;) - 291 KB:
+ IPRoute2 (&iproute2-version;) - 377 KB:
Home page:
@@ -315,7 +307,7 @@
- Linux (&linux-version;) - 36,522 KB:
+ Linux (&linux-version;) - 39,884 KB:
Home page:
Download:
- Udev (&udev-version;) - 427 KB:
+ Udev (&udev-version;) - 185 KB:
Home page:
diff --git a/chapter03/patches.xml b/chapter03/patches.xml
index 9a6132cbc..3bb1068b4 100644
--- a/chapter03/patches.xml
+++ b/chapter03/patches.xml
@@ -138,7 +138,7 @@
- Linux kernel UTF-8 Composing Patch - 3 KB:
+ Linux kernel UTF-8 Composing Patch - 11 KB:
diff --git a/chapter05/changingowner.xml b/chapter05/changingowner.xml
new file mode 100644
index 000000000..b80ebb1b4
--- /dev/null
+++ b/chapter05/changingowner.xml
@@ -0,0 +1,46 @@
+
+
+ %general-entities;
+]>
+
+
+
+
+ Changing Ownership
+
+
+ The commands in the remainder of this book must be performed while
+ logged in as user root and no
+ longer as user lfs. Also, double
+ check that $LFS is set in root's environment.
+
+
+ Currently, the /tools directory
+ is owned by the user lfs, a user
+ that exists only on the host system. If the /tools directory is kept as is, the files are
+ owned by a user ID without a corresponding account. This is dangerous because
+ a user account created later could get this same user ID and would own the
+ /tools directory and all the files
+ therein, thus exposing these files to possible malicious manipulation.
+
+ To avoid this issue, you could add the lfs user to the new LFS system later when
+ creating the /etc/passwd file, taking care to assign it
+ the same user and group IDs as on the host system. Better yet, change the
+ ownership of the /tools directory to
+ user root by running the following
+ command:
+
+chown -R root:root /tools
+
+ Although the /tools directory can
+ be deleted once the LFS system has been finished, it can be retained to build
+ additional LFS systems of the same book version. How best
+ to backup /tools is a matter of
+ personal preference and is left as an exercise for the reader.
+
+
diff --git a/chapter05/chapter05.xml b/chapter05/chapter05.xml
index 02739479f..df3d854bb 100644
--- a/chapter05/chapter05.xml
+++ b/chapter05/chapter05.xml
@@ -42,5 +42,6 @@
+
diff --git a/chapter06/changingowner.xml b/chapter06/changingowner.xml
deleted file mode 100644
index 83deca414..000000000
--- a/chapter06/changingowner.xml
+++ /dev/null
@@ -1,40 +0,0 @@
-
-
- %general-entities;
-]>
-
-
-
-
- Changing Ownership
-
- Currently, the /tools directory
- is owned by the user lfs, a user
- that exists only on the host system. Although the /tools directory can be deleted once the LFS
- system has been finished, it can be retained to build additional LFS systems.
- If the /tools directory is kept as is,
- the files are owned by a user ID without a corresponding account. This is
- dangerous because a user account created later could get this same user ID
- and would own the /tools directory
- and all the files therein, thus exposing these files to possible malicious
- manipulation.
-
- To avoid this issue, add the lfs
- user to the new LFS system later when creating the
- /etc/passwd file, taking care to assign it the same user
- and group IDs as on the host system. Alternatively, assign the contents of
- the /tools directory to user
- root by running the following
- command:
-
-chown -R 0:0 /tools
-
- The command uses 0:0 instead of
- root:root, because chown
- is unable to resolve the name root
until the
- passwd file has been created.
-
-
diff --git a/chapter06/chapter06.xml b/chapter06/chapter06.xml
index 4186fd7bb..5715d6be9 100644
--- a/chapter06/chapter06.xml
+++ b/chapter06/chapter06.xml
@@ -12,14 +12,11 @@
Installing Basic System Software
-
+
-
-
-
@@ -53,7 +50,6 @@
-
diff --git a/chapter06/chroot.xml b/chapter06/chroot.xml
index ca3e86a92..ea213033e 100644
--- a/chapter06/chroot.xml
+++ b/chapter06/chroot.xml
@@ -44,16 +44,18 @@
reason, hashing is switched off by passing the +h option
to bash.
- It is important that all the commands throughout the remainder of this
- chapter and the following chapters are run from within the chroot environment.
- If you leave this environment for any reason (rebooting for example), remember
- to first mount the proc and
- devpts file systems (discussed
- in the previous section) and enter chroot again before continuing with the
- installations.
-
Note that the bash prompt will say
I have no name! This is normal because the
/etc/passwd file has not been created yet.
+
+ It is important that all the commands throughout the remainder of this
+ chapter and the following chapters are run from within the chroot
+ environment. If you leave this environment for any reason (rebooting for
+ example), ensure that the virtual kernel filesystems are mounted as
+ explained in and and enter chroot again before continuing
+ with the installation.
+
+
diff --git a/chapter06/createfiles.xml b/chapter06/createfiles.xml
index ae22a241d..0cfc7596f 100644
--- a/chapter06/createfiles.xml
+++ b/chapter06/createfiles.xml
@@ -8,7 +8,31 @@
- Creating Essential Symlinks
+ Creating Essential Files and Symlinks
+
+
+ /etc/passwd
+
+
+
+ /etc/group
+
+
+
+ /var/run/utmp
+
+
+
+ /var/log/btmp
+
+
+
+ /var/log/lastlog
+
+
+
+ /var/log/wtmp
+
Some programs use hard-wired paths to programs which do not exist yet. In
order to satisfy these programs, create a number of symbolic links which will be
@@ -20,4 +44,94 @@ ln -sv /tools/bin/perl /usr/bin
ln -sv /tools/lib/libgcc_s.so{,.1} /usr/lib
ln -sv bash /bin/sh
+ A proper Linux system maintains a list of the mounted file systems in
+ the file /etc/mtab. Normally, this file would be
+ created when we mount a new file system. Since we will not be mounting any
+ file systems inside our chroot environment, create an empty file for
+ utilities that expect the presence of /etc/mtab:
+
+touch /etc/mtab
+
+ In order for user root to be
+ able to login and for the name root
to be recognized, there
+ must be relevant entries in the /etc/passwd and
+ /etc/group files.
+
+ Create the /etc/passwd file by running the following
+ command:
+
+cat > /etc/passwd << "EOF"
+root:x:0:0:root:/root:/bin/bash
+EOF
+
+ The actual password for root
+ (the x
used here is just a placeholder) will be set later.
+
+ Create the /etc/group file by running the following
+ command:
+
+cat > /etc/group << "EOF"
+root:x:0:
+bin:x:1:
+sys:x:2:
+kmem:x:3:
+tty:x:4:
+tape:x:5:
+daemon:x:6:
+floppy:x:7:
+disk:x:8:
+lp:x:9:
+dialout:x:10:
+audio:x:11:
+video:x:12:
+utmp:x:13:
+usb:x:14:
+cdrom:x:15:
+EOF
+
+ The created groups are not part of any standard—they are groups
+ decided on in part by the requirements of the Udev configuration in this
+ chapter, and in part by common convention employed by a number of existing
+ Linux distributions. The Linux Standard Base (LSB, available at ) recommends only that, besides the group
+ root with a Group ID (GID) of 0,
+ a group bin with a GID of 1 be
+ present. All other group names and GIDs can be chosen freely by the system
+ administrator since well-written programs do not depend on GID numbers, but
+ rather use the group's name.
+
+ To remove the I have no name!
prompt, start a new
+ shell. Since a full Glibc was installed in and the
+ /etc/passwd and /etc/group
+ files have been created, user name and group name resolution will now
+ work.
+
+exec /tools/bin/bash --login +h
+
+ Note the use of the +h directive. This tells
+ bash not to use its internal path hashing. Without this
+ directive, bash would remember the paths to binaries it has
+ executed. To ensure the use of the newly compiled binaries as soon as they are
+ installed, the +h directive will be used for the duration
+ of this chapter.
+
+ The login, agetty, and
+ init programs (and others) use a number of log
+ files to record information such as who was logged into the system and
+ when. However, these programs will not write to the log files if they
+ do not already exist. Initialize the log files and give them
+ proper permissions:
+
+touch /var/run/utmp /var/log/{btmp,lastlog,wtmp}
+chgrp -v utmp /var/run/utmp /var/log/lastlog
+chmod -v 664 /var/run/utmp /var/log/lastlog
+
+ The /var/run/utmp file records the users
+ that are currently logged in. The /var/log/wtmp
+ file records all logins and logouts. The
+ /var/log/lastlog file records when
+ each user last logged in. The /var/log/btmp file
+ records the bad login attempts.
+
diff --git a/chapter06/creatingdirs.xml b/chapter06/creatingdirs.xml
index b9a269ebc..4e602b356 100644
--- a/chapter06/creatingdirs.xml
+++ b/chapter06/creatingdirs.xml
@@ -13,7 +13,7 @@
It is time to create some structure in the LFS file system. Create a
standard directory tree by issuing the following commands:
-install -dv /{bin,boot,dev,etc/opt,home,lib,mnt}
+install -dv /{bin,boot,etc/opt,home,lib,mnt}
install -dv /{sbin,srv,usr/local,var,opt}
install -dv /root -m 0750
install -dv /tmp /var/tmp -m 1777
diff --git a/chapter06/devices.xml b/chapter06/devices.xml
deleted file mode 100644
index 51821fe84..000000000
--- a/chapter06/devices.xml
+++ /dev/null
@@ -1,93 +0,0 @@
-
-
- %general-entities;
-]>
-
-
-
-
- Populating /dev
-
-
- /dev/*
-
-
-
- Creating Initial Device Nodes
-
- When the kernel boots the system, it requires the presence of a few
- device nodes, in particular the console
- and null devices. The device nodes
- will be created on the hard disk so that they are available before
- udev has been started, and additionally when Linux is
- started in single user mode (hence the restrictive permissions on
- console). Create the devices by
- running the following commands:
-
-mknod -m 600 /dev/console c 5 1
-mknod -m 666 /dev/null c 1 3
-
-
-
-
- Mounting tmpfs and Populating /dev
-
- The recommended method of populating the /dev directory with devices is to mount a
- virtual filesystem (such as tmpfs)
- on the /dev directory, and allow the
- devices to be created dynamically on that virtual filesystem as they are
- detected or accessed. This is generally done during the boot process. Since
- this new system has not been booted, it is necessary to do what the
- LFS-Bootscripts package would otherwise do by mounting /dev:
-
-mount -nvt tmpfs none /dev
-
- The Udev package is what actually creates the devices in the /dev directory. Since it will not be installed
- until later on in the process, manually create the minimal set of device nodes
- needed to complete the building of this system:
-
-mknod -m 622 /dev/console c 5 1
-mknod -m 666 /dev/null c 1 3
-mknod -m 666 /dev/zero c 1 5
-mknod -m 666 /dev/ptmx c 5 2
-mknod -m 666 /dev/tty c 5 0
-mknod -m 444 /dev/random c 1 8
-mknod -m 444 /dev/urandom c 1 9
-chown -v root:tty /dev/{console,ptmx,tty}
-
- There are some symlinks and directories required by LFS that are
- created during system startup by the LFS-Bootscripts package. Since this
- is a chroot environment and not a booted environment, those symlinks and
- directories need to be created here:
-
-ln -sv /proc/self/fd /dev/fd
-ln -sv /proc/self/fd/0 /dev/stdin
-ln -sv /proc/self/fd/1 /dev/stdout
-ln -sv /proc/self/fd/2 /dev/stderr
-ln -sv /proc/kcore /dev/core
-mkdir -v /dev/pts
-mkdir -v /dev/shm
-
- Finally, mount the proper virtual (kernel) file systems on the
- newly-created directories:
-
-mount -vt devpts -o gid=4,mode=620 none /dev/pts
-mount -vt tmpfs none /dev/shm
-
- The mount commands executed above may result
- in the following warning message:
-
-can't open /etc/fstab: No such file or directory.
-
- This file—/etc/fstab—has not
- been created yet but is also not required for the file systems to be
- properly mounted. As such, the warning can be safely ignored.
-
-
-
-
diff --git a/chapter06/hotplug.xml b/chapter06/hotplug.xml
deleted file mode 100644
index d66e0c7e7..000000000
--- a/chapter06/hotplug.xml
+++ /dev/null
@@ -1,223 +0,0 @@
-
-
- %general-entities;
-]>
-
-
-
-
- Hotplug-&hotplug-version;
-
-
- Hotplug
-
-
-
-
-
- The Hotplug package contains scripts that react upon hotplug events
- generated by the kernel. Such events correspond to every change in the kernel
- state visible in the sysfs
- filesystem, e.g., the addition and removal of hardware. This package also
- detects existing hardware during boot and inserts the relevant modules into the
- running kernel.
-
-
- &buildtime;
- &diskspace;
-
-
- 0.01 SBU
- 460 KB
-
-
-
-
- &dependencies;
-
-
- Bash, Coreutils, Findutils, Gawk, and Make
-
-
-
-
-
-
- Installation of Hotplug
-
- This package does not come with a test suite.
-
- Install the Hotplug package:
-
-make install
-
- Copy a file that the install
target omits.
-
-cp -v etc/hotplug/pnp.distmap /etc/hotplug
-
- Remove the init script that Hotplug installs since we are going to be
- using the script included in the LFS-Bootscripts package:
-
-rm -rfv /etc/init.d
-
- Network device hotplugging is not yet supported by the LFS-Bootscripts
- package. For that reason, remove the network hotplug agent:
-
-rm -fv /etc/hotplug/net.agent
-
- Create a directory for storing firmware that can be loaded by
- hotplug:
-
-mkdir -v /lib/firmware
-
-
-
-
-
- Contents of Hotplug
-
-
- Installed program
- Installed scripts
- Installed files
-
-
- hotplug
- /etc/hotplug/*.rc, /etc/hotplug/*.agent
- /etc/hotplug/hotplug.functions, /etc/hotplug/blacklist,
- /etc/hotplug/{pci,usb}, /etc/hotplug/usb.usermap, /etc/hotplug.d,
- and /var/log/hotplug/events
-
-
-
-
- Short Descriptions
-
-
-
-
- hotplug
-
- This script is called by default by the Linux kernel when
- something changes in its internal state (e.g., a new device is
- added or an existing device is removed)
-
- hotplug
-
-
-
-
-
- /etc/hotplug/*.rc
-
- These scripts are used for cold plugging, i.e., detecting and
- acting upon hardware already present during system startup. They are
- called by the hotplug initscript included in
- the LFS-Bootscripts package. The *.rc scripts try
- to recover hotplug events that were lost during system boot because,
- for example, the root filesystem was not mounted by the kernel
-
- /etc/hotplug/*.rc
-
-
-
-
-
- /etc/hotplug/*.agent
-
- These scripts are called by hotplug in response
- to different types of hotplug events generated by the kernel. Their
- action is to insert corresponding kernel modules and call any
- user-provided scripts
-
- /etc/hotplug/*.agent
-
-
-
-
-
- /etc/hotplug/blacklist
-
- This file contains the list of modules that should never be
- inserted into the kernel by the Hotplug scripts
-
- /etc/hotplug/blacklist
-
-
-
-
-
- /etc/hotplug/hotplug.functions
-
- This file contains common functions used by other scripts in the
- Hotplug package
-
- /etc/hotplug/hotplug.functions
-
-
-
-
-
- /etc/hotplug/{pci,usb}
-
- These directories contain user-written handlers for hotplug
- events
-
- /etc/hotplug/{pci,usb}
-
-
-
-
-
- /etc/hotplug/usb.usermap
-
- This file contains rules that determine which user-defined handlers to
- call for each USB device, based on its vendor ID and other
- attributes
-
- /etc/hotplug/usb.usermap
-
-
-
-
-
- /etc/hotplug.d
-
- This directory contains programs (or symlinks to them) that are
- interested in receiving hotplug events. For example, Udev puts its
- symlink here during installation
-
- /etc/hotplug.d
-
-
-
-
-
- /lib/firmware
-
- This directory contains the firmware for devices that need to
- have their firmware loaded before use
-
- /lib/firmware
-
-
-
-
-
- /var/log/hotplug/events
-
- This file contains all the events that hotplug
- has called since bootup
-
- /var/log/hotplug/events
-
-
-
-
-
-
-
-
-
diff --git a/chapter06/introduction.xml b/chapter06/introduction.xml
index 5e9cfd5c3..588d84780 100644
--- a/chapter06/introduction.xml
+++ b/chapter06/introduction.xml
@@ -55,11 +55,4 @@
there is a list of programs and libraries (along with brief descriptions of
these) that the package installs.
-
- At this point, you may wish to keep your finished temporary
- tools for use in future LFS builds by creating a tarball of the
- /tools directory and
- storing it in a safe location.
-
-
diff --git a/chapter06/iproute2.xml b/chapter06/iproute2.xml
index 84e4244e0..fdf93aa08 100644
--- a/chapter06/iproute2.xml
+++ b/chapter06/iproute2.xml
@@ -25,8 +25,8 @@
&diskspace;
- 0.1 SBU
- 4.3 MB
+ 0.2 SBU
+ 4.8 MB
diff --git a/chapter06/kernfs.xml b/chapter06/kernfs.xml
index 2bdf9f9c3..3c9e68c0b 100644
--- a/chapter06/kernfs.xml
+++ b/chapter06/kernfs.xml
@@ -8,33 +8,72 @@
- Mounting Virtual Kernel File Systems
+ Preparing Virtual Kernel File Systems
- Various file systems exported by the kernel are used to communicate to and
- from the kernel itself. These file systems are virtual in that no disk space is
- used for them. The content of the file systems resides in memory.
+
+ /dev/*
+
- Begin by creating directories onto which the file systems will be
- mounted:
+ Various file systems exported by the kernel are used to communicate to
+ and from the kernel itself. These file systems are virtual in that no disk
+ space is used for them. The content of the file systems resides in
+ memory.
-mkdir -pv $LFS/{proc,sys}
+ Begin by creating directories onto which the file systems will be
+ mounted:
- Now mount the file systems:
+mkdir -pv $LFS/{dev,proc,sys}
-mount -vt proc proc $LFS/proc
+
+ Creating Initial Device Nodes
+
+ When the kernel boots the system, it requires the presence of a few
+ device nodes, in particular the console and null devices. The device nodes will be created
+ on the hard disk so that they are available before udev
+ has been started, and additionally when Linux is started in single user mode
+ (hence the restrictive permissions on console). Create the devices by running the
+ following commands:
+
+mknod -m 600 $LFS/dev/console c 5 1
+mknod -m 666 $LFS/dev/null c 1 3
+
+
+
+
+ Mounting and Populating /dev
+
+ The recommended method of populating the /dev directory with devices is to mount a
+ virtual filesystem (such as tmpfs) on the /dev directory, and allow the devices to be
+ created dynamically on that virtual filesystem as they are detected or
+ accessed. This is generally done during the boot process by Udev. Since
+ this new system does not yet have Udev and has not yet been booted, it is
+ necessary to mount and populate /dev manually. This is accomplished by bind
+ mounting the host system's /dev
+ directory. A bind mount is a special type of mount that allows you to
+ create a mirror of a directory or mount point to some other location. Use
+ the following command to achieve this:
+
+mount --bind /dev $LFS/dev
+
+
+
+
+ Mounting Virtual Kernel File Systems
+
+ Now mount the remaining virtual kernel filesystems:
+
+mount -vt devpts devpts $LFS/dev/pts
+mount -vt tmpfs shm $LFS/dev/shm
+mount -vt proc proc $LFS/proc
mount -vt sysfs sysfs $LFS/sys
- Remember that if for any reason you stop working on the LFS
- system and start again later, it is important to check that these file
- systems are mounted again before entering the chroot
- environment.
-
- Additional file systems will soon be mounted from within the
- chroot environment. To keep the host up to date, perform a fake
- mount
for each of these now:
-
-mount -vft tmpfs tmpfs $LFS/dev
-mount -vft tmpfs tmpfs $LFS/dev/shm
-mount -vft devpts -o gid=4,mode=620 devpts $LFS/dev/pts
+
diff --git a/chapter06/pkgmgt.xml b/chapter06/pkgmgt.xml
index 76ea123e2..4ce94106d 100644
--- a/chapter06/pkgmgt.xml
+++ b/chapter06/pkgmgt.xml
@@ -39,14 +39,6 @@
the Hints subproject and see if one of them
fits your need.
-
- As no particular package management technique is mentioned in LFS,
- the commands in the remainder of this book must be performed while logged in
- as user root and no longer as user
- lfs. Also, double check that
- $LFS is set.
-
-
Upgrade Issues
diff --git a/chapter06/udev.xml b/chapter06/udev.xml
index 96d2ec579..f78ab1cec 100644
--- a/chapter06/udev.xml
+++ b/chapter06/udev.xml
@@ -26,7 +26,7 @@
0.1 SBU
- 3.8 MB
+ 4.8 MB
@@ -43,19 +43,31 @@
Installation of Udev
+ Create some devices and directories that Udev cannot handle due to
+ them being required very early in the boot process:
+
+install -dv /lib/{firmware,udev/devices/{pts,shm}}
+mknod -m0666 /lib/udev/devices/null c 1 3
+ln -sv /proc/self/fd /lib/udev/devices/fd
+ln -sv /proc/self/fd/0 /lib/udev/devices/stdin
+ln -sv /proc/self/fd/1 /lib/udev/devices/stdout
+ln -sv /proc/self/fd/2 /lib/udev/devices/stderr
+ln -sv /proc/kcore /lib/udev/devices/core
+
Compile the package:
-make EXTRAS=extras/run_directory
+make EXTRAS="extras/ata_id extras/cdrom_id extras/edd_id \
+ extras/firmware extras/floppy extras/scsi_id \
+ extras/usb_id extras/volume_id"
The meaning of the make option:
- EXTRAS=extras/run_directory
+ EXTRAS=...
- This builds the udev_run_devd and
- udev_run_hotplugd binaries, which are required
- for correct handling of hotpluggable devices.
+ This builds several helper binaries that can aid in writing custom
+ Udev rules.
@@ -66,7 +78,10 @@
Install the package:
-make DESTDIR=/ EXTRAS=extras/run_directory install
+make DESTDIR=/ \
+ EXTRAS="extras/ata_id extras/cdrom_id extras/edd_id \
+ extras/firmware extras/floppy extras/scsi_id \
+ extras/usb_id extras/volume_id" install
The meaning of the make parameter:
@@ -87,16 +102,78 @@
cp -v ../&udev-config-file; /etc/udev/rules.d/25-lfs.rules
+ Create some rules that work around broken sysfs attribute creation
+ timing in linux-2.6.15:
+
+cat >> /etc/udev/rules.d/10-wait_for_sysfs.rules << "EOF"
+ACTION=="add", DEVPATH=="/devices/*", ENV{PHYSDEVBUS}=="?*", WAIT_FOR_SYSFS="bus"
+ACTION=="add", SUBSYSTEM=="net", WAIT_FOR_SYSFS="address"
+EOF
+
Install the documentation that explains how to create Udev rules:
install -m644 -D -v docs/writing_udev_rules/index.html /usr/share/doc/udev-&udev-version;/index.html
-
-
- Run the udevstart program to create our full
- complement of device nodes.
+
-/sbin/udevstart
+ When Udev is started by the LFS-Bootscripts, a replay of all kernel
+ device events happens. These events tell Udev what devices exist.
+ Sometimes the Udev bootscript doesn't wait long enough for
+ udevd to process all of the replayed events and
+ consequently the devices for those missed events are not created before the
+ script exits. Since udevd is still running in the
+ background, the devices will be created a few milliseconds later, but the
+ next bootscript to run may require a device to exist before it has been
+ created. To avoid such missed events, and to avoid hardcoding an overly
+ long wait time, It is recommended that you run the following commands to
+ aid the LFS development team in debugging these missed events and finding
+ an acceptable solution more quickly.
+
+ First, create a simple C file:
+
+cat > bug.c << EOF
+/* Simple event recorder */
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <argz.h>
+int main(int argc, char * argv[])
+{
+ char * envz;
+ size_t len;
+ int bug;
+ bug = open("/dev/bug", O_WRONLY | O_APPEND);
+ if (bug == -1)
+ return 0;
+ setenv("_SEPARATOR", "--------------------------------------", 1);
+ argz_create(environ, &envz, &len);
+ argz_stringify(envz, len, '\n');
+ envz[len-1]='\n';
+ write(bug, envz, len);
+ close(bug);
+ free(envz);
+ return 0;
+}
+EOF
+
+ Now compile it:
+
+gcc -o /lib/udev/bug bug.c
+
+ The next step adds a simple logging rule to run this program.
+
+cat > /etc/udev/rules.d/90-bug.rules << "EOF"
+ACTION=="add", RUN+="bug"
+EOF
+
+ When booting the new LFS system, if any events are missed, a warning
+ message will appear and a /dev/bugreport file will be
+ created. The warning message will tell you where to send feedback.
+
+
@@ -108,8 +185,9 @@
Installed directory
- udev, udev_run_devd, udev_run_hotplugd, udevcontrol, udevd,
- udevinfo, udevmonitor, udevsend, udevstart, and udevtest
+ ata_id, cdrom_id, create_floppy_devices, edd_id, firmware_helper,
+ scsi_id, udevcontrol, udevd, udevinfo, udevmonitor, udevtest, usb_id
+ and vol_id
/etc/udev
@@ -119,38 +197,66 @@
-
- udev
+
+ ata_id
- Creates device nodes in /dev
- or renames network interfaces (not in LFS) in response to hotplug
- events
-
- udev
+ Provides Udev with a unique string and
+ additional information (uuid, label) for an ATA drive
+
+ ata_id
-
- udev_run_devd
+
+ cdrom_id
- Executes programs and scripts in the /etc/dev.d/ directory in response to
- hotplug events
-
- udev_run_devd
+ Provides Udev with the capabilities of a
+ CD-ROM or DVD-ROM drive
+
+ cdrom_id
-
- udev_run_hotplugd
+
+ create_floppy_devices
- Executes programs and scripts in the /etc/hotplug.d/ directory in response
- to hotplug events
-
- udev_run_hotplugd
+ Creates all possible floppy devices based on the CMOS type
+
+ create_floppy_devices
+
+
+
+
+
+ edd_id
+
+ Provides Udev with the EDD ID for a BIOS disk drive
+
+ edd_id
+
+
+
+
+
+ firmware_helper
+
+ Uploads firmware to devices
+
+ firmware_helper
+
+
+
+
+
+ scsi_id
+
+ Provides Udev with a unique SCSI identifier
+ based on the data returned from sending a SCSI INQUIRY command to
+ the specified device
+
+ scsi_id
@@ -169,8 +275,9 @@
udevd
- A daemon that reorders hotplug events before submitting them to
- udev, thus avoiding various race conditions
+ A daemon that listens for uevents on the netlink socket,
+ creates devices and runs the configured external programs in
+ response to these uevents
udevd
@@ -180,7 +287,7 @@
udevinfo
- Allows users to query the udev database for
+ Allows users to query the Udev database for
information on any device currently present on the system; it also
provides a way to query any device in the sysfs tree to help create udev
@@ -194,56 +301,52 @@
udevmonitor
- Prints the event received from the kernel and the event which
- udev sends out after rule processing
+ Prints the event received from the kernel and the environment
+ which Udev sends out after rule processing
udevmonitor
-
- udevsend
-
- Delivers hotplug events to udevd
-
- udevsend
-
-
-
-
-
- udevstart
-
- Creates device nodes in /dev
- that correspond to drivers compiled directly into the kernel; it
- performs that task by simulating hotplug events presumably dropped by
- the kernel before invocation of this program (e.g., because the root
- filesystem has not been mounted) and submitting such synthetic hotplug
- events to udev
-
- udevstart
-
-
-
-
udevtest
- Simulates a udev run for the given device,
- and prints out the name of the node the real udev
- would have created or (not in LFS) the name of the renamed network
- interface
+ Simulates a uevent for the given device, and prints out the
+ name of the node the real udevd would have created,
+ or the name of the renamed network interface
udevtest
+
+ usb_id
+
+ Provides Udev with information about USB
+ devices
+
+ usb_id
+
+
+
+
+
+ vol_id
+
+ Provides Udev with the label and uuid of a
+ filesystem
+
+ vol_id
+
+
+
+
/etc/udev
- Contains udev configuation files,
+ Contains Udev configuation files,
device permissions, and rules for device naming
/etc/udev
diff --git a/chapter07/bootscripts.xml b/chapter07/bootscripts.xml
index 775215e7e..a5c589c76 100644
--- a/chapter07/bootscripts.xml
+++ b/chapter07/bootscripts.xml
@@ -56,7 +56,7 @@
Installed scripts
- checkfs, cleanfs, console, functions, halt, hotplug, ifdown, ifup,
+ checkfs, cleanfs, console, functions, halt, ifdown, ifup,
localnet, mountfs, mountkernfs, network, rc, reboot, sendsignals,
setclock, static, swap, sysklogd, template, and udev
@@ -125,16 +125,6 @@
-
- hotplug
-
- Loads modules for system devices
-
- hotplug
-
-
-
-
ifdown
diff --git a/chapter07/network.xml b/chapter07/network.xml
index c09f92431..ac6082271 100644
--- a/chapter07/network.xml
+++ b/chapter07/network.xml
@@ -23,6 +23,48 @@
symlinks from all run-level directories (/etc/rc.d/rc*.d).
+
+ Creating stable names for network interfaces
+
+ Instructions in this section are optional if you have only one
+ network card.
+
+ With Udev and modular network drivers, the network interface numbering
+ is not persistent across reboots by default, because the drivers are loaded
+ in parallel and, thus, in random order. For example, on a computer having
+ two network cards made by Intel and Realtek, the network card manufactured
+ by Intel may become eth0 and the
+ Realtek card becomes eth1. In some
+ cases, after a reboot the cards get renumbered the other way around. To
+ avoid this, create Udev rules that assign stable names to network cards
+ based on their MAC addresses.
+
+ First, find out the MAC addresses of your network cards:
+
+grep -H . /sys/class/net/*/address
+
+ For each network card (but not for the loopback interface),
+ invent a descriptive name, such as realtek
, and create
+ Udev rules similar to the following:
+
+cat > /etc/udev/rules.d/26-network.rules << "EOF"
+ACTION=="add", SUBSYSTEM=="net", SYSFS{address}=="52:54:00:12:34:56", NAME="realtek"
+ACTION=="add", SUBSYSTEM=="net", SYSFS{address}=="00:a0:c9:78:9a:bc", NAME="intel"
+EOF
+
+ These rules will always rename the network cards to
+ realtek
and intel
, independently of the
+ original numbering provided by the kernel. Use these names instead of
+ eth0
in the network interface configuration files created
+ below.
+
+
+ Persistent names must be different from the default network
+ interface names assigned by the kernel.
+
+
+
+
Creating Network Interface Configuration Files
diff --git a/chapter07/udev.xml b/chapter07/udev.xml
index 5f98e6139..7d4bcc495 100644
--- a/chapter07/udev.xml
+++ b/chapter07/udev.xml
@@ -23,13 +23,15 @@
Linux systems in general traditionally use a static device creation
method, whereby a great many device nodes are created under /dev (sometimes literally thousands of nodes),
- regardless of whether the corresponding hardware devices actually exist. This is
- typically done via a MAKEDEV script, which contains a number
- of calls to the mknod program with the relevant major and
- minor device numbers for every possible device that might exist in the world.
- Using the Udev method, only those devices which are detected by the kernel get
- device nodes created for them. Because these device nodes will be created each
- time the system boots, they will be stored on a MAKEDEV script, which contains a
+ number of calls to the mknod program with the relevant
+ major and minor device numbers for every possible device that might exist in
+ the world.
+
+ Using the Udev method, only those devices which are detected by the
+ kernel get device nodes created for them. Because these device nodes will be
+ created each time the system boots, they will be stored on a tmpfs file system (a virtual file system that
resides entirely in system memory). Device nodes do not require much space, so
the memory that is used is negligible.
@@ -50,160 +52,278 @@
naming, was perhaps the most critical. It is generally accepted that if
device names are allowed to be configurable, then the device naming policy
should be up to a system administrator, not imposed on them by any
- particular developer(s). The devfs
- file system also suffers from race conditions that are inherent in its design
- and cannot be fixed without a substantial revision to the kernel. It has also
- been marked as deprecated due to a lack of recent maintenance.
+ particular developer(s). The devfs file system also suffers from race
+ conditions that are inherent in its design and cannot be fixed without a
+ substantial revision to the kernel. It has also been marked as deprecated
+ due to a lack of recent maintenance.
- With the development of the unstable 2.5 kernel tree, later released as
- the 2.6 series of stable kernels, a new virtual filesystem called sysfs came to be. The job of sysfs is to export a view of the system's
- hardrware configuration to userspace processes. With this userspace-visible
- representation, the possibility of seeing a userspace replacement for
- devfs became much more
- realistic.
+ With the development of the unstable 2.5 kernel tree, later released
+ as the 2.6 series of stable kernels, a new virtual filesystem called
+ sysfs came to be. The job of
+ sysfs is to export a view of
+ the system's hardware configuration to userspace processes. With this
+ userspace-visible representation, the possibility of seeing a userspace
+ replacement for devfs became
+ much more realistic.
Udev Implementation
- The sysfs filesystem was
- mentioned briefly above. One may wonder how sysfs knows about the devices present on
- a system and what device numbers should be used for them. Drivers that have
- been compiled into the kernel directly register their objects with
- sysfs as they are detected by
- the kernel. For drivers compiled as modules, this registration will happen
- when the module is loaded. Once the sysfs filesystem is mounted (on /sys), data which the built-in drivers
- registered with sysfs are
- available to userspace processes and to udev for device
- node creation.
+
+ Sysfs
- The S10udev initscript takes care of creating
- these device nodes when Linux is booted. This script starts by registering
- /sbin/udevsend as a hotplug event handler. Hotplug events
- (discussed below) are not usually generated during this stage, but
- udev is registered just in case they do occur. The
- udevstart program then walks through the /sys filesystem and creates devices under
- /dev that match the descriptions.
- For example, /sys/class/tty/vcs/dev contains the
- string 7:0
This string is used by udevstart
- to create /dev/vcs with major number
- 7 and minor 0. The names and
- permissions of the nodes created under the /dev directory are configured according to the
- rules specified in the files within the /etc/udev/rules.d/ directory. These are
- numbered in a similar fashion to the LFS-Bootscripts package. If
- udev can't find a rule for the device it is creating,
- it will default permissions to 660 and ownership to
- root:root.
+ The sysfs filesystem was
+ mentioned briefly above. One may wonder how sysfs knows about the devices present on
+ a system and what device numbers should be used for them. Drivers that
+ have been compiled into the kernel directly register their objects with
+ sysfs as they are detected by
+ the kernel. For drivers compiled as modules, this registration will happen
+ when the module is loaded. Once the sysfs filesystem is mounted (on /sys), data which the built-in drivers
+ registered with sysfs are
+ available to userspace processes and to udevd for device
+ node creation.
- Once the above stage is complete, all devices that were already present
- and have compiled-in drivers will be available for use. This leads us to the
- devices that have modular drivers.
+
- Earlier, we mentioned the concept of a hotplug event
- handler.
When a new device connection is detected by the kernel,
- the kernel will generate a hotplug event and look at the file
- /proc/sys/kernel/hotplug to determine the userspace
- program that handles the device's connection. The udev
- bootscript registered udevsend as this handler. When
- these hotplug events are generated, the kernel will tell
- udev to check the /sys filesystem for the information pertaining
- to this new device and create the /dev
- entry for it.
+
+ Udev Bootscript
- This brings us to one problem that exists with udev,
- and likewise with devfs before it.
- It is commonly referred to as the chicken and egg
problem. Most
- Linux distributions handle loading modules via entries in
- /etc/modules.conf. Access to a device node causes the
- appropriate kernel module to load. With udev, this method
- will not work because the device node does not exist until the module is loaded.
- To solve this, the S05modules bootscript was added to the
- LFS-Bootscripts package, along with the
- /etc/sysconfig/modules file. By adding module names to the
- modules file, these modules will be loaded when the
- computer starts up. This allows udev to detect the devices
- and create the appropriate device nodes.
+ The S10udev initscript takes care of creating
+ device nodes when Linux is booted. The script starts by unsetting the
+ hotplug event handler from the default of /sbin/hotplug
+ This is done because, instead of the kernel calling out to an external
+ binary, udevd will listen on a netlink socket for
+ hotplug events that the kernel raises. The bootscript copies any static
+ device nodes that exist in /lib/udev/devices to /dev. This is necessary because some devices,
+ directories and symlinks are needed before the dynamic device handling
+ processes are available during the early stages of booting a system.
+ Creating static device nodes in
+ /lib/udev/devices also provides
+ an easy workaround for devices that are not supported by the dynamic
+ device handling infrastructure. The bootscript then starts the Udev
+ daemon, udevd, which will act on any hotplug events it
+ receives. Finally, the bootscript "coldplugs" any devices that
+ have already been registered with the kernel by forcing them to raise
+ hotplug events which udevd will then handle.
- Note that on slower machines or for drivers that create a lot of device
- nodes, the process of creating devices may take a few seconds to complete.
- This means that some device nodes may not be immediately accessible.
+
+
+
+ Device Node Creation
+
+ To obtain the right major and minor number for a device, Udev relies
+ on the information provided by sysfs in /sys. For example,
+ /sys/class/tty/vcs/dev contains the string
+ 7:0
. This string is used by udevd
+ to create a device node with major number 7 and minor
+ 0. The names and permissions of the nodes created
+ under the /dev directory are
+ determined by rules specified in the files within the /etc/udev/rules.d/ directory. These are
+ numbered in a similar fashion to the LFS-Bootscripts package. If
+ udevd can't find a rule for the device it is creating,
+ it will default permissions to 660 and ownership to
+ root:root. Documentation on the syntax of the Udev
+ rules configuration files are available in
+ /usr/share/doc/udev-&udev-version;/index.html
+
+
+
+
+ Module Loading
+
+ Device drivers compiled as modules may have aliases built into them.
+ Aliases are visible in the output of the modinfo
+ program and are usually related to the bus-specific identifiers of devices
+ supported by a module. For example, the snd-fm801
+ driver supports PCI devices with vendor ID 0x1319 and device ID 0x0801,
+ and has an alias of pci:v00001319d00000801sv*sd*bc04sc01i*
.
+ For most devices, the bus driver exports the alias of the driver that
+ would handle the device via sysfs. E.g., the
+ /sys/bus/pci/devices/0000:00:0d.0/modalias file
+ might contain the string
+ pci:v00001319d00000801sv00001319sd00001319bc04sc01i00
.
+ The rules that LFS installs will cause udevd to call
+ out to /sbin/modprobe with the contents of the
+ MODALIAS uevent environment variable (that should be the
+ same as the contents of the modalias file in sysfs),
+ thus loading all modules whose aliases match this string after wildcard
+ expansion.
+
+ In this example, this means that, in addition to
+ snd-fm801, the obsolete (and unwanted)
+ forte driver will be loaded if it is
+ available. See below for ways in which the loading of unwanted drivers can
+ be prevented.
+
+ The kernel itself is also able to load modules for network
+ protocols, filesystems and NLS support on demand.
+
+
+
+
+ Handling Hotpluggable/Dynamic Devices
+
+ When you plug in a device, such as a Universal Serial Bus (USB) MP3
+ player, the kernel recognizes that the device is now connected and
+ generates a hotplug event. This hotplug event is then handled by
+ udevd as described above.
+
+
- Handling Hotpluggable/Dynamic Devices
+ Problems with Loading Modules and Creating Devices
- When you plug in a device, such as a Universal Serial Bus (USB) MP3
- player, the kernel recognizes that the device is now connected and generates
- a hotplug event. If the driver is already loaded (either because it was
- compiled into the kernel or because it was loaded via the
- S05modules bootscript), udev will be
- called upon to create the relevant device node(s) according to the
- sysfs data available in
- /sys.
+ There are a few possible problems when it comes to automatically
+ creating device nodes.
- If the driver for the just plugged in device is available as a module but
- currently unloaded, the Hotplug package will load the appropriate module
- and make this device available by creating the device node(s) for it.
+
+ A kernel module is not loaded automatically
-
+ Udev will only load a module if it has a bus-specific alias and the
+ bus driver properly exports the necessary aliases to sysfs. In other cases, one should
+ arrange module loading by other means. With Linux-&linux-version;, Udev is
+ known to load properly-written drivers for PCI, USB, SCSI, SERIO and
+ FireWire devices.
-
- Problems with Creating Devices
+
- There are a few known problems when it comes to automatically creating
- device nodes:
+ To determine if the device driver you require has the necessary
+ support for Udev, run modinfo with the module name as
+ the argument. Now try locating the device directory under
+ /sys/bus and check whether there is
+ a modalias file there.
- 1) A kernel driver may not export its data to sysfs.
+ If the modalias file exists in sysfs, the driver supports the device and
+ can talk to it directly, but doesn't have the alias, it is a bug in the
+ driver. Load the driver without the help from Udev and expect the issue
+ to be fixed later.
- This is most common with third party drivers from outside the kernel
- tree. Udev will be unable to automatically create device nodes for such
- drivers. Use the /etc/sysconfig/createfiles
- configuration file to manually create the devices. Consult the
- devices.txt file inside the kernel documentation or
- the documentation for that driver to find the proper major/minor
- numbers.
+ If there is no modalias file in the relevant
+ directory under /sys/bus, this
+ means that the kernel developers have not yet added modalias support to
+ this bus type. With Linux-&linux-version;, this is the case with ISA and
+ IDE busses. Expect this issue to be fixed in later kernel versions.
- 2) A non-hardware device is required. This is most common with
- the Advanced Linux Sound Architecture (ALSA) project's Open Sound
- System (OSS) compatibility module. These types of devices can be
- handled in one of two ways:
+
-
+ Udev is not intended to load wrapper
drivers such as
+ snd-pcm-oss and non-hardware drivers such as
+ loop at all.
-
- Adding the module names to
- /etc/sysconfig/modules
-
+
-
- Using an install
line in
- /etc/modprobe.conf. This tells the
- modprobe command when loading this module,
- also load this other module, at the same time.
- For example:
+
+ A kernel module is not loaded automatically, and Udev is not
+ intended to load it
-install snd-pcm modprobe -i snd-pcm ; modprobe \
- snd-pcm-oss ; true
+ If the wrapper
module only enhances the functionality
+ provided by some other module (e.g., snd-pcm-oss
+ enhances the functionality of snd-pcm by making the
+ sound cards available to OSS applications), configure
+ modprobe to load the wrapper after Udev loads the
+ wrapped module. To do this, add an install
line in
+ /etc/modprobe.conf. For example:
- This will cause the system to load both the
- snd-pcm and snd-pcm-oss
- modules when any request is made to load the driver
- snd-pcm.
-
+install snd-pcm modprobe -i snd-pcm ; modprobe \
+ snd-pcm-oss ; true
-
+ If the module in question is not a wrapper and is useful by itself,
+ configure the S05modules bootscript to load this
+ module on system boot. To do this, add the module name to the
+ /etc/sysconfig/modules file on a separate line.
+ This works for wrapper modules too, but is suboptimal in that case.
+
+
+
+
+ Udev loads some unwanted module
+
+ Either don't build the module, or blacklist it in
+ /etc/modprobe.conf file as done with the
+ forte module in the example below:
+
+blacklist forte
+
+ Blacklisted modules can still be loaded manually with the
+ explicit modprobe command.
+
+
+
+
+ Udev creates a device incorrectly, or makes a wrong symlink
+
+ This usually happens if a rule unexpectedly matches a device. For
+ example, a poorly-writen rule can match by both a SCSI disk (as desired)
+ and the corresponding SCSI generic device (incorrectly) by vendor.
+ Increase the logging verbosity of Udev, find the offending rule by
+ examining the logs and make it more specific.
+
+
+
+
+ Udev rule works unreliably
+
+ This may be another manifestation of the previous problem. If not,
+ and your rule uses sysfs
+ attributes, it may be a kernel timing issue, to be fixed in later kernels.
+ For now, you can work around it by creating a rule that waits for the used
+ sysfs attribute and appending
+ it to the /etc/udev/rules.d/10-wait_for_sysfs.rules
+ file. Please notify the LFS Development list if you do so and it
+ helps.
+
+
+
+
+ Udev does not create a device
+
+ Further text assumes that the driver is built statically into the
+ kernel or already loaded as a module, and that you have already checked
+ that Udev doesn't create a misnamed device.
+
+ Udev has no information needed to create a device node if a kernel
+ driver does not export its data to sysfs.
+ This is most common with third party drivers from outside the kernel
+ tree. Create a static device node in
+ /lib/udev/devices with the appropriate major/minor
+ numbers (see the file devices.txt inside the kernel
+ documentation or the documentation provided by the third party driver
+ vendor). The static device node will be copied to
+ /dev by the
+ S10udev bootscript.
+
+
+
+
+ Device naming order changes randomly after rebooting
+
+ This is due to the fact that Udev, by design, handles uevents and
+ loads modules in parallel, and thus in an unpredictable order. This will
+ never be fixed
. You should not rely upon the kernel device
+ names being stable. Instead, create your own rules that make symlinks with
+ stable names based on some stable attributes of the device, such as a
+ serial number or the output of various *_id utilities installed by Udev.
+ See also the network interface renaming example in
+ .
+
+
diff --git a/chapter08/kernel.xml b/chapter08/kernel.xml
index 9a9de871b..ad2573624 100644
--- a/chapter08/kernel.xml
+++ b/chapter08/kernel.xml
@@ -24,8 +24,8 @@
&diskspace;
- 4.20 SBU
- 181 MB
+ 2.4 SBU
+ 344 MB
@@ -98,27 +98,13 @@
make
- If using kernel modules, an /etc/modprobe.conf file
- may be needed. Information pertaining to modules and kernel configuration is
- located in the kernel documentation in the If using kernel modules, an /etc/modprobe.conf
+ file may be needed. Information pertaining to modules and kernel
+ configuration is located in and in the
+ kernel documentation in the linux-&linux-version;/Documentation directory.
Also, modprobe.conf(5) may be of interest.
- Be very careful when reading other documentation relating to kernel
- modules because it usually applies to 2.4.x kernels only. As far as we know,
- kernel configuration issues specific to Hotplug and Udev are not documented.
- The problem is that Udev will create a device node only if Hotplug or a
- user-written script inserts the corresponding module into the kernel, and not
- all modules are detectable by Hotplug. Note that statements like the one below
- in the /etc/modprobe.conf file do not work with
- Udev:
-
-alias char-major-XXX some-module
-
- Because of the complications with Hotplug, Udev, and modules, we
- strongly recommend starting with a completely non-modular kernel
- configuration, especially if this is the first time using Udev.
-
Install the modules, if the kernel configuration uses them:
make modules_install
diff --git a/general.ent b/general.ent
index bcf9a8b85..3123456b7 100644
--- a/general.ent
+++ b/general.ent
@@ -1,6 +1,6 @@
-
-
+
+
@@ -52,15 +52,14 @@
-
-
+
-
+
-
+
@@ -83,8 +82,8 @@
-
-
+
+
diff --git a/patches.ent b/patches.ent
index 07ff10904..fa33436cb 100644
--- a/patches.ent
+++ b/patches.ent
@@ -30,7 +30,7 @@
-
+