JDK GNU/Linux SPARC and MIPS

[Sunil Amitkumar Janki]

Jonathan Springer wrote:
> The biggest part of porting is the core Hotspot virtual machine 
> itself.  The amount of code that needs to be rewritten to port that to 
> a new platform depends on whether either or both of OS or hardware are 
> new.  OpenJDK is well-organized in that it separates out the 
> platform-dependent code into separate directories.  There are three 
> categories of platform-dependent directory: os, cpu, and os_cpu.
>
> The easiest of your ports would be Linux-SPARC, since there are 
> already directories os=linux and cpu=sparc, so you would just have to 
> write the code in os_cpu=linux_sparc. This is probably about 2500 
> LOC.  Ports to a new os are harder, requiring about 10k LOC (could be 
> more if the OS is especially primitive).  Ports to a new cpu are the 
> hardest, requiring from maybe 25k to 45k LOC, depending on the route 
> you choose and whether you do all the parts.
>
> (Redirected from distro-pkg-dev since this isn't really a distro 
> discussion.)

I have downloaded the latest OpenJDK source code from the OpenJDK
site and checked out the latest IcedTea repository. I want to get 
Linux/SPARC working first so I would like to know if it's better
to start from Solaris/SPARC or Linux/i586 and if there is a big 
difference between Solaris and Linux support.

Neither do I have much experience with this kind of software since I 
have mostly programmed higher-level Java applications. I also have
some C++ experience but nothing as low level as this. So I would 
appreciate it if there was some kind of guide or overview of what
the OpenJDK code is all about.

I also have some knowledge of x86, MIPS and PPC assembly language, 
though it is very basic. I am however prepared to read a lot of 
documentation to get a better understanding of the JDK.

Sunil