udev: generate blacklist on boot

udev will read /etc/modprobe.d/*.conf and blacklist all modules that are listed as

blacklist <module>

We parse rc.conf at boot and generate such a .conf file. It cannot be written to
/etc this early, so we save it to /run. A symlink exists in /etc to get the desired
functionality.

With this patch (and an analogous one in mkinitcpio) load-modules.sh can be removed
from the udev package without loss of significant functionality.

Setting MOD_AUTOLOAD will then no longer take effect, nor will kernel parameters.
Thouhgh, kernel parameters might still affect the initramfs as the implementation
is independent.

Original-idea-by: Benjamen Richer <br@waldteufel-online.net>
Based-on-patch-by: David Reisner <d@falconindy.com>
Signed-off-by: Tom Gundersen <teg@jklm.no>

1 files changed, 25 insertions, 0 deletions

diff --git a/modprobe-blacklist b/modprobe-blacklist
new file mode 100755
index 0000000..8af5d90
--- /dev/null
+++ b/modprobe-blacklist
@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# /etc/rc.gen-modules-list
+#
+
+. /etc/rc.conf
+
+declare -a blacklist
+for mod in "${MODULES[@]}"; do
+	case $mod in
+		!*) blacklist+=("${mod:1}") ;;
+		*) ;;
+	esac
+done
+
+# create new module blacklist in /run/initscripts, there should be a symlink in /etc/modprobe.d/ pointing here
+if [[ $blacklist ]]; then
+	/bin/mkdir -p /run/initscripts
+	echo "# Autogenerated from rc.conf at boot, do not edit" > /run/initscripts/modprobe-blacklist.conf
+	(( ${#blacklist[@]} )) && printf 'blacklist %s\n' "${blacklist[@]}" >> /run/initscripts/modprobe-blacklist.conf
+fi
+
+unset blacklist
+
+# vim: set noet ts=2 sw=2: