[LEDE-DEV] [OpenWrt-Devel] Adding host Java support to the buildbots

[Dana Myers]

On 12/29/2016 11:50 PM, Ralph Sennhauser wrote:
> Hi Dana
>
> On Thu, 29 Dec 2016 12:30:37 -0800
> Dana Myers <k6jq at comcast.net> wrote:
>
>> In reference to https://github.com/openwrt/packages/pull/3686
>>
>> We've added OpenWRT support for:
>>
>> * JamVM 2.0: Java JVM
>> * GNU Classpath 2.0: Java class library
> There is no classpath 2.0

Right you are - serves me right for spewing version numbers off the top
of my head from something I initially did two years :-) It's classpath 0.99
>
>> * RXTX Java serial communications library
>>
>> However, the build bots won't build these packages yet because
>> a host Java compiler is required. To build these packages, I
>> install:
> The main reason to use jamvm with gnu classpath is you can bootstrap it
> without a jdk, right? If you already require a host jdk why not go for
> jamvm with the openjdk classpath to get full java support?

I don't understand the question about bootstrapping and host vs target JDK.
Host JDK is used specifically for javac to compile Java to bytecodes; target has
no dependency on JDK otherwise.

Classpath was, for many years, the only library supported by JamVM, is much
smaller than OpenJDK (valuable on resource-constrained systems) and remains
the default library supported by JamVM. For the purposes of my project from which
I contributed, Classpath is adequate and appears to avoid concerns about encumbrance
of the target builds/devices with OpenJDK. Most specifically, however, was the apparent
lack of support for MIPS32 which is a show-stopper for the AR71xx architecture I'm using.

If someone is interested in contributing OpenJDK, I'd be happy to consult.

>
>>       openjdk-7-jdk
>>
>> (which also pulls in openjdk-7-jre and openjdk-7-jre-headless)
>>
>> What needs to be done to add openjdk-7-jdk to the build bots?

Something like 'apt-get install openjdk-7-jdk' (if I recall correctly, still on coffee #1
here).

Cheers,
Dana