Mottek: 2003-04-29

Something completely different

... well, not really. But I took a closer look at the latest ARM compilers to find out how to make them work with the Newton tools. The advantage of using the ARM compilers are probably better code generation and definitely the support for StrongARM specific opcodes. The most interesting case are the 64 bit multiplication operations and support for 64 bit integers which are more or less required for optimized MP3 and Ogg decoding (you see where I'm getting at...)

Turns out that it is not impossible to use the new compilers, but also not trivial. The first hurdle is of course how to get the compilers. Thankfully, I can play with the latest tools at work, including the ADS tools. But the next step is a bit more challenging. The ARM tools are a distinct relative of the Norcroft tools used by the NCT. They differ however in the file formats they use. The ARM tools are nowadays ELF-based, whereas the Norcroft tools used AIF and AOF as object formats. This requires that the complete compilation and linking process has to be done with the same tool chain. Switching file formats in between stages doesn't really work that well...

The last step in that process is the conversion from an AIF image to the format used by the NTK. This step is done by the AIFtoNTK tool that unfortunately does not like the AIF image created by the new ARMLink and FromELF tools. Add the different debugging symbols to the mix and you end up with a total mess. But all is not lost, the AIFtoNTK tool might be easy to reverse engineer (it is only a couple of dozen kilobytes large). It takes the code, relocation and debugging symbol areas from the AIF and puts them in an NTK wrapper. That shouldn't be too hard to reimplement...

However, there are still quite a few other projects I'd like to improve before I get back to this.