Where in OpenJDK repository can I find Hotspot VM source codes?

[zengyijie]

Hi, we are running an outdated Oracle Java JDK6 with Hotspot VM, I have spent quite a while browsing openjdk repository,
but I can’t find the source codes for the specific Hotspot VM version. The repository tip of http://hg.openjdk.java.net/jdk6/jdk6/hotspot/ <http://hg.openjdk.java.net/jdk6/jdk6/hotspot/> is only jdk6-b43, there’s no 1.6.0_45.
Could someone help tell where to find it?
The Oracle JDK version is as follows:

java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode)