README.md

*** 8,5 ***
--- 8,39 ---
  - [doc/building.md](doc/building.md) (markdown version)
  
  See <https://openjdk.org/> for more information about the OpenJDK
  Community and the JDK and see <https://bugs.openjdk.org> for JDK issue
  tracking.
+ 
+ ## Particulars related to Babylon
+ 
+ The Babylon JDK builds like any other JDK, see the build instructions above.
+ 
+ ### Code shared between `java.base` and `jdk.compiler` modules
+ 
+ A subset of code in `java.base` is copied with package renaming into
+ the `jdk.compiler` module. This is the set of code required to build
+ and serialize code models. Due to bootstrapping constraints, compiling
+ the compiler it cannot depend on all code in `java.base`. In the future
+ we may come up with a better solution. For now the build has been modified
+ to copy the code, which leverages the script `cr-util/copy-to-compiler.sh`.
+ 
+ ### Testing
+ 
+ Specific compiler tests can be executed using `jtreg`, for example:
+ 
+ ```
+ jtreg -jdk:./build/macosx-x86_64-server-release/jdk/ -ea -esa -avm -va test/langtools/tools/javac/reflect/
+ ```
+ 
+ Specific runtime tests can be executed using `jtreg`, for example:
+ 
+ ```
+ jtreg -jdk:./build/macosx-x86_64-server-release/jdk/ -ea -esa -avm -va test/jdk/java/lang/reflect/code/
+ ```
+ 
+ In addition, the runtime tests can be executed using make with the test group
+ `jdk_lang_reflect_code` as follows:
+ 
+ ```
+ make test TEST=jdk_lang_reflect_code
+ ```