Add -j option to scripts/crosscompile

docs/Rakefile

@@ -75,7 +75,7 @@ $BINARIES = {
 
 $BINARIES.each do |name, args|
   file "../build/#{name}" do |t|
-    sh "MAKEFLAGS=-j4 ../scripts/crosscompile #{name} #{args}"
+    sh "../scripts/crosscompile -j4 #{name} #{args}"
   end
   task :binaries => ["../build/#{name}"]
 end

scripts/crosscompile

@@ -13,6 +13,11 @@
 set -e
 cd `dirname "$0"`/../build
 
+jobs=-j4
+case "X$1" in
+X-j*) jobs=$1; shift;;
+esac
+
 plat="$1"
 [ -z "$plat" ] && exit 1
 shift
@@ -26,6 +31,7 @@ mkdir install_other
     --prefix="`pwd`/install_other" \
     --bindir="`pwd`/.." \
     "$@"
-make install-binaries
+make "$jobs" install-binaries
 cd ..
 rm -rf tmp
+