Hi Maciej, > In any case you'll have to find a MIPS I or MIPS II distribution, like an > older version of Debian. I will see what I can find. I currently have Black Rhino based on Debian and tailored for the R5900, as you verified. > The three-argument MUL is a part of the base MIPS32 architecture BTW, > originating from the IDT R4650 and the NEC Vr5500 processors. It has > nothing to do with the DSP ASE (though it may have been claimed originally > to be a DSP enhancement). Ah, I was referring to a press release that appears to be written by MIPS Technologies (linked from Wikipedia): In addition, DSP enhancements such as multiply (MUL) and multiply and add (MADD) instructions have been standardized and added to the new architectures. While these instructions have been available as licensee-specific extensions in the past, this is the first time that they have been available as a standard part of the MIPS(R) architecture. https://www.thefreelibrary.com/MIPS+Technologies,+Inc.+Enhances+Architecture+to+Support+Growing+Need...-a054531136 > > For this reason the R5900 patch modifies the __{save,restore}_dsp macros, > > mips_dsp_state::dspcontrol, DSP_INIT, sigcontext32::sc_dsp, etc. I've seen > > the cpu_has_dsp macro too, but haven't looked at the details of this yet. > > Given that the R5900 does not expand DSP support anyhow that sounds > suspicious to me. Yes, I agree. Fredrik