Compile procedure headers

Rakefile

@@ -7,8 +7,28 @@ CROSS_GCC = '../riscv32-ilp32d--glibc/bin/riscv32-linux-gcc'
 SYSROOT = '../riscv32-ilp32d--glibc/riscv32-buildroot-linux-gnu/sysroot'
 QEMU = 'qemu-riscv32'
 
+def assemble_stage(output, compiler, source)
+  arguments = [QEMU, '-L', SYSROOT, *compiler]
+
+  puts(arguments * ' ')
+  puts
+  Open3.popen2(*arguments) do |qemu_in, qemu_out|
+    qemu_in.write File.read(*source)
+    qemu_in.close
+
+    IO.copy_stream qemu_out, output
+    qemu_out.close
+  end
+end
+
 desc 'Final stage'
-task default: 'build/stage2'
+task default: ['build/stage2', 'boot/stage2.elna'] do |t|
+  assembler, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
+
+  File.open File::NULL, 'w' do |output|
+    assemble_stage output, exe, assembler
+  end
+end
 
 directory 'build'
 
@@ -21,18 +41,9 @@ end
 
 file 'build/stage2.s' => ['build/stage1', 'boot/stage2.elna'] do |t|
   assembler, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
-  arguments = [QEMU, '-L', SYSROOT, *exe]
 
-  puts(arguments * ' ')
-  puts
-  Open3.popen2(*arguments) do |qemu_in, qemu_out|
-    qemu_in.write File.read(*assembler)
-    qemu_in.close
-
-    File.open t.name, 'w' do |output|
-      IO.copy_stream qemu_out, output
-    end
-    qemu_out.close
+  File.open t.name, 'w' do |output|
+    assemble_stage output, exe, assembler
   end
 end