[yyjjll]

Greetings, I'm kinda new here ...

I wonder if there's anyway to run embedded C programs on the 7100 device, below the Java VM layers, and above the OS.

A major problem with the Java VM is it's too slow for computationally intensive tasks.

I've asked RIM about this issue and of course I got the answer no, since Java Midlet is the only thing officially opened to developers.

However, according to what I've found, 7100 runs on an ARM processor, and nothing should prevent one from running compiled C/C++ programs on the processor.

Does anyone have any idea on this? Thanks.

[Mark Rejhon]

Unfortunately, no, there is no way. RIM threw in a lot of security mechanisms for a very good reason (government, etc). These mechanisms are not unique, a similiar example is how difficult it has been to "hack" a Microsoft X-Box to run Linux, for example.

If you have a critical routine that you MUST optimize to run as fast as possible, one way is to to use Java bytecode assembler, which is something not for the faint of heart. Very few people have the courage to try bytecode assembly for Java, and it is not standardized, but it provides a method of low-level programming in Java Virtual Machine bytecode. Google for "Jasmin Java" for more info. You'll probably be jumping through a lot of hoops to modify files in an existing .jar file (decompile into Jasmin, edit the file, and recompile back to bytecode). Be warned, that this is extremely, extremely DIFFICULT. But it will be valid Java bytecode on all JVM's.

Also, not all the BlackBerries use the same processor. No guarantee's you'll be running on an ARM9.

[yyjjll]

Thanks Mark.

[AndyCanfield]

I ran into the same problem for doing thing like projection transformations for my GIS apps on the Blackberry. I ended up using a fixed point library for a lot of stuff but for things like the projection shifting I mentioned I had to go to the server side to do it. Speed wasn't so much of an issue for me as accuracy was and with fixed point I wasn't able to get the precision I needed. I needed between 14 and 29 places behind the decimal and the digits in front of the decimal needed to go up to the millions and tens of millions positions. My fixed point library keeps track of both the digits in front and behind the decimal within a single integer for speed reasons vice a class that keeps track of two integers per number. So there simply wasn't enough room in my fixed point stuff for that kind of accuracy. Bottom line was I ended up doing a lot of server side stuff for those computations and then pass the result back to the device. All the server side stuff for the most part is done in C++ with a few libraries being in C. However we have a ton of bandwidth for our mds where I work so even with 50+ users hitting the app at the same time it's still so fast the users don't know that the computation for some of it is being done server side not device side. We use 7510's, and like your 7100, RIM has it locked down so it's d@mn near impossible to bootstrap in your own C or C++ app.

[DoomBringer]

Write your own C interpreter in Java... ha