[base system & package/block-extroot] Merged 23110-23112 which allows block-extroot to be

loaded as a module rather than being required to be in the image.  Thanks JoW for pushing
and helping with this.


git-svn-id: svn://svn.openwrt.org/openwrt/branches/backfire@23113 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/base-files/files/lib/functions/boot.sh

@@ -6,19 +6,66 @@ mount() {
 	/bin/busybox mount "$@"
 }
 
+boot_hook_splice_start() {
+	export -n PI_HOOK_SPLICE=1
+}
+
+boot_hook_splice_finish() {
+	local hook
+	for hook in $PI_STACK_LIST; do
+		local v; eval "v=\${${hook}_splice:+\$${hook}_splice }$hook"
+		export -n "${hook}=${v% }"
+		export -n "${hook}_splice="
+	done
+	export -n PI_HOOK_SPLICE=
+}
+
+boot_hook_init() {
+	local hook="${1}_hook"
+	export -n "PI_STACK_LIST=${PI_STACK_LIST:+$PI_STACK_LIST }$hook"
+	export -n "$hook="
+}
+
 boot_hook_add() {
-    	local hook="${1}_hook"
-	local value="$2"
-	local sep=" "
-	
-	eval "$hook=\"\${$hook:+\${$hook}\${value:+\$sep}}\$value\""
+	local hook="${1}_hook${PI_HOOK_SPLICE:+_splice}"
+	local func="${2}"
+
+	[ -n "$func" ] && {
+		local v; eval "v=\$$hook"
+		export -n "$hook=${v:+$v }$func"
+	}
+}
+
+boot_hook_shift() {
+	local hook="${1}_hook"
+	local rvar="${2}"
+
+	local v; eval "v=\$$hook"
+	[ -n "$v" ] && {
+		local first="${v%% *}"
+
+		[ "$v" != "${v#* }" ] && \
+			export -n "$hook=${v#* }" || \
+			export -n "$hook="
+
+		export -n "$rvar=$first"
+		return 0
+	}
+
+	return 1
 }
 
 boot_run_hook() {
-    local boot_func
-    for boot_func in $(eval "echo \"\$${1}_hook\""); do
-	$boot_func "$1" "$2"
-    done
+	local hook="$1"
+	local func
+
+	while boot_hook_shift "$hook" func; do
+		local ran; eval "ran=\$PI_RAN_$func"
+		[ -n "$ran" ] || {
+			export -n "PI_RAN_$func=1"
+			$func "$1" "$2"
+		}
+	done
 }
 
 find_mtd_part() {
@@ -98,3 +145,4 @@ ramoverlay() {
 	mount -t tmpfs root /tmp/root
 	fopivot /tmp/root /rom 1
 }
+