Portable ARM Basic and SWI trapping.

In :
http://stardot.org.uk/forums/viewtopic.php?f=29&t=11764&p=151653#p151653
Richard Russel (developer of BBC Basic for Windows, as well as other versions), mentions a portable version of his version of BBC BASIC nominally developed for SDL. The proposal was seemingly that some kind of glue-logic was developed such that means that the BASIC module from RISC OS Open could be used on Pi., as it’s designed specifically with the ARM processor in mind. It was felt here might have more ARM programmers, then stardot would.

The technical challenges mentioned in the post are :-

• How to trap SWI’s and convert them into a branch into the emulation layer.
• How to ensure that the BASIC Module gets a relocatable workspace as opposed to a fixed-address one.

Also mentioning here – https://github.com/dboddie/ARM-BBC-BASIC-Plus-for-Android ( which despite the name is NOT Android specific).

It would be interesting, if BASIC (and ARM BASIC Plus) could be made fully relocatable for other reasons, not least the addition of additional features more modern languages now support.(BB4W unlike ARM BASIC V has function pointers.)

Richard Russels’s SDL based framework might also be of interest in implementing ways around the fact that some lo-color modes don’t necessarily work with modern GPU hardware.