Also some minor cleanups to the dracut script.
---
HOWTO.dracut-modules | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++
dracut | 19 +++++---------
2 files changed, 74 insertions(+), 12 deletions(-)
diff --git a/HOWTO.dracut-modules b/HOWTO.dracut-modules
new file mode 100644
index 0000000..82c5606
--- /dev/null
+++ b/HOWTO.dracut-modules
@@ -0,0 +1,67 @@
+How to write a dracut module:
+
+BASIC CONCEPTS
+
+Dracut builds an initramfs by sourcing a bunch of different modules
+from the modules.d directory in the location dracut was installed to
+that perform most of the work of actually installing files on to the
+initramfs. Modules are either directories or symlinks to directories
+that contain an "install" script. These install scripts are sourced
+in directory name lexical order, and should do all the actual work of
+installing the module on to the initrams. Current convention says
+that these directories should begin with two digits, and that the
+numbers 90 - 99 are reserved for dracut.
+
+INSTALLING FILES
+
+There are several different functions defined in dracut-functions
+which should be used to install files. They all handle installing any
+needed dependencies (modules, shared libraries, script interpreters),
+and handle pathname mangling as needed to ensure files get installed
+to the correct location on the initramfs. The inst functions never
+overwrite a file that is already installed on the initramfs, so if you
+need to override functionality in another module, arrange for your
+module to be sourced first and to use the same filenames that the later
+module you want to override uses. The inst functions are:
+
+instmods -- This function takes any number of parameters, all of which
+should be either module names or module group names. Module group
+names should begin with an equals (=) sign, and will include by
+reference all the modules mentioned in
+/lib/modules/$(uname -r)/modules.{groupname}. As a special case,
+"=ata" will include just the modules for sata and pata controllers.
+Instmods also handles installing all module and firmware dependencies
+that the module declares.
+
+dracut_install -- This function takes any number of parameters, all of
+which must be either a full path to a filename or the name of a
+binary. It will install that file on the initramfs with the same name
+and path as the original file.
+
+inst_hook -- This function installs a hook. It takes 3 parameters:
+ $1 = the type of hook. Currently, there are pre-udev,
+ pre-mount, mount, and pre-pivot hooks.
+ $2 = hook priority. This is a 2 digit number in the range
+ of 00 - 99. Lower numbers run first.
+ $3 = Full path to the hook to install.
+
+inst_rule -- This function installs udev rules. It takes any number
+of parameters, and installs all files in /lib/udev/rules.d on the initramfs.
+
+inst -- This function is a general-purpose file installation
+function. It takes 2 parameters:
+ $1 = The source file. If this is not the full path to the
+ source file, we will try to search for it as a binary file.
+ $2 (optional) = The destination on the initramfs for the
+ file. If this is omitted, the installation location will have
+ the same path as the source file.
+
+USEFUL VARIABLES:
+
+$initdir = The directory that the initramfs is being built in. If you
+need to install something that one of the inst functions does not
+handle, you can use this to figure out where the initramfs root
+filesystem is.
+
+$moddir = The location of the current module. Use this to install
+files from the module.
diff --git a/dracut b/dracut
index 5811f57..dacc9e6 100755
--- a/dracut
+++ b/dracut
@@ -3,12 +3,10 @@
# Generator script for a dracut initramfs
# Tries to retain some degree of compatibility with the command line
# of the various mkinitrd implementations out there
-#
# Copyright 2008, Red Hat, Inc. Jeremy Katz <[email protected]>
# GPLv2 header here
-
[ -f /etc/dracut.conf ] && . /etc/dracut.conf
while (($# > 0)); do
@@ -24,7 +22,7 @@ while (($# > 0)); do
esac
shift
done
-[[ $dracutmodules ]] || dracutmodules="all"
+[[ $dracutmodules ]] || dracutmodules="all"
[[ $2 ]] && kernel=$2 || kernel=$(uname -r)
[[ $1 ]] && outfile=$(readlink -f $1) || outfile="/boot/initrd-$kernel.img"
@@ -36,26 +34,23 @@ fi
[[ $allowlocal && -f dracut-functions ]] && dsrc="." ||
dsrc=/usr/libexec/dracut
. $dsrc/dracut-functions
-initfile=$dsrc/init
-switchroot=$dsrc/switch_root
-rulesdir=$dsrc/rules.d
-hookdirs="pre-udev pre-mount pre-pivot"
+hookdirs="pre-udev pre-mount pre-pivot mount"
-initdir=$(mktemp -d -t initramfs.XXXXXX)
+readonly initdir=$(mktemp -d -t initramfs.XXXXXX)
trap 'rm -rf "$initdir"' 0 # clean up after ourselves no matter how we die.
-export initdir hookdirs rulesdir dsrc dracutmodules modules
+export initdir hookdirs dsrc dracutmodules modules
# Create some directory structure first
-for d in bin sbin usr/bin usr/sbin usr/lib etc proc sys sysroot dev/pts; do
- mkdir -p "$initdir/$d";
+for d in bin sbin usr/bin usr/sbin usr/lib etc proc sys sysroot dev/pts; do
+ mkdir -p "$initdir/$d"
done
# source all our modules
for moddir in "$dsrc/modules.d"/*; do
[[ -d $moddir || -L $moddir ]] || continue
mod=${moddir##*/}; mod=${mod#[0-9][0-9]};
- if [[ $dracutmodules = all ]] || strstr "$dracutmodules" "$mod"; then
+ if [[ $dracutmodules = all ]] || strstr "$dracutmodules" "$mod"; then
[[ -x $moddir/install ]] && . "$moddir/install"
fi
done
--
1.6.0.6
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