update compilation notes

doc/compile/README.md

@@ -183,6 +183,39 @@ If you want mrbtest.a only, You should set ```conf.build_mrbtest_lib_only```
 
 	conf.build_mrbtest_lib_only
 
+### Bintest
+
+Tests for mrbgem tools using CRuby.
+To have bintests place *.rb scripts to ```bintest/``` directory of mrbgems.
+See ```mruby-bin-*/bintest/*.rb``` if you need examples.
+If you want a temporary files use `tempfile` module of CRuby instead of ```/tmp/```.
+
+You can enable it with following:
+
+	conf.enable_bintest = true
+
+### C++ ABI
+
+mruby can use C++ exception to raise exception internally.
+It is called C++ ABI mode.
+By using C++ exception it can release C++ stack object correctly.
+Whenever you mix C++ code C++ ABI mode would be enabled automatically.
+If you need to enable C++ ABI mode explicity add the following:
+
+	conf.enable_cxx_abi
+
+### Debugging mode
+
+To enable debugging mode add the following:
+
+	conf.enable_debug
+
+When debugging mode is enabled
+* Macro ```MRB_DEBUG``` would be defined.
+	* Which means ```mrb_assert()``` macro is enabled.
+* Debug information of irep would be generated by ```mrbc```.
+	* Because ```-g``` flag would be added to ```mrbc``` runner.
+    * You can have better backtrace of mruby scripts with this.
 
 ## Cross-Compilation
 
@@ -202,6 +235,20 @@ like this:
 All configuration options of ```MRuby::Build``` can also be used
 in ```MRuby::CrossBuild```.
 
+### Mrbtest in Cross-Compilation
+
+In cross compilation, you can run ```mrbtest``` on emulator if
+you have it by changing configuration of test runner.
+
+	conf.test_runner do |t|
+      t.command = ... # set emulator. this value must be non nil or false
+      t.flags = ... # set flags of emulator
+
+	  def t.run(bin) # override `run` if you need to change the behavior of it
+	    ... # `bin` is the full path of mrbtest
+	  end
+	end
+
 ## Build process
 
 During the build process the directory *build* will be created in the