runtime: Add boot option to preload kernel modules

Signed-off-by: Alexey Gladkov <[email protected]>

Author: legionus

Documentation/BootParameters.md

@@ -15,6 +15,8 @@ The following parameters can be passed via kernel command line.
 - `rd-preload-modules` enables/disables loading a static list of modules before udev service.
 - `rd.driver.blacklist=<comma-separated list>` specifies the list of kernel
   module names that should be added to blacklist before loading any kernel modules.
+- `rd.driver.pre=<comma-separated list>` specifies the list of kernel module
+  names that should be preloaded.
 
 Parameters responsible for mounting the root file system:
 

features/runtime/data/etc/initrd/cmdline.d/base

@@ -23,3 +23,4 @@ register_parameter string ROOTFLAGS
 register_parameter string ROOTFSTYPE
 register_parameter string STOP
 register_array string RD_DRIVER_BLACKLIST
+register_array string RD_DRIVER_PRE

features/runtime/data/etc/rc.d/init.d/modules

@@ -42,6 +42,25 @@ fi
 preload_modules()
 {
 	local check conf modname rc=0
+
+	if [ "${RD_DRIVER_PRE:-0}" != 0 ]; then
+		local i modnames MODS
+
+		i=0
+		while [ $i -lt ${RD_DRIVER_PRE:-0} ]; do
+			eval "MODS=\"\$RD_DRIVER_PRE$i\""
+
+			modnames=()
+			readarray -t -d, modnames <<<"$MODS,"
+
+			for modname in "${modnames[@]}"; do
+				[ -n "$modname" ] && [ "$modname" != $'\n' ] ||
+					continue
+				modprobe "$modname" || rc=1
+			done
+		done
+	fi 2>"/var/log/preload-modules.log"
+
 	for conf in /etc/modules-load.d/*.conf /run/modules-load.d/*.conf /lib/modules-load.d/*.conf /etc/initrd/modules-preudev; do
 		# shellcheck disable=SC2162
 		[ ! -e "$conf" ] ||
@@ -53,7 +72,7 @@ preload_modules()
 				continue
 			modprobe "$modname" $args || rc=1
 		done < "$conf"
-	done 2>"/var/log/preload-modules.log"
+	done 2>>"/var/log/preload-modules.log"
 	return $rc
 }