wip: better packaging?

pkgs/development/misc/msp430/gcc-support.nix

···
     '';
     homepage = https://www.ti.com/tool/msp430-gcc-opensource;
     license = licenses.bsd3;
-    platforms = platforms.all;
+    platforms = [ "msp430-none" ];
     maintainers = with maintainers; [ aerialx ];
   };
 }

pkgs/development/misc/msp430/newlib.nix

···
-{ runCommand, lndir, newlib, msp430GccSupport }:
+{ stdenvNoCC, lndir, newlib, msp430GccSupport }:
 
-runCommand "msp430-${newlib.name}" {
+stdenvNoCC.mkDerivation {
+  name = "msp430-${newlib.name}";
   inherit newlib;
   inherit msp430GccSupport;
 
   preferLocalBuild = true;
   allowSubstitutes = false;
+
+  buildCommand = ''
+    mkdir $out
+    ${lndir}/bin/lndir -silent $newlib $out
+    ${lndir}/bin/lndir -silent $msp430GccSupport/include $out/${newlib.incdir}
+    ${lndir}/bin/lndir -silent $msp430GccSupport/lib $out/${newlib.libdir}
+  '';
 
   passthru = {
     inherit (newlib) incdir libdir;
   };
-} ''
-  mkdir $out
-  ${lndir}/bin/lndir -silent $newlib $out
-  ${lndir}/bin/lndir -silent $msp430GccSupport/include $out/${newlib.incdir}
-  ${lndir}/bin/lndir -silent $msp430GccSupport/lib $out/${newlib.libdir}
-''
+
+  meta = {
+    platforms = [ "msp430-none" ];
+  };
+}