How to read the source of DartVM?

How to read the source of DartVM?

I'm trying to learn more about Dart, so I want to read the source of dart.
The dart vm is written in c++, and the code base is huge.
I get the source code from https://github.com/dart-lang/bleeding_edge
Following is just the code inside the runtime package, you can see it has
more than 180K lines of c++ code.
➜ runtime git:(master) ✗ cloc .
752 text files.
746 unique files.
47 files ignored.
http://cloc.sourceforge.net v 1.58 T=6.0 s (117.7 files/s, 52169.5 lines/s)
-------------------------------------------------------------------------------
Language files blank comment
code
-------------------------------------------------------------------------------
C++ 375 32722 21436
180070
C/C++ Header 238 10936 8753
36452
Dart 76 2785 1340
16661
Python 13 254 211
1113
C 2 28 28
107
Bourne Shell 1 16 11
85
Assembly 1 1 3
5
-------------------------------------------------------------------------------
SUM: 706 46742 31782
234493
-------------------------------------------------------------------------------
I have learnt dart for one month, and I've several years of Java
development experience, but I don't know c++. Could someone give me some
advice about learning dart vm? I have a long term plan to learn dart vm.
My question is, to learn dart vm, what kind of knowledge is more
important, that I'd better pay some time to learn it:
Do I need to master c++ before I can really read the source of dart vm?
Do I need to read some books about VM design? If there is any?
Is there any documents or books or blogs about Dart VM that I should read?
and any other advice