Hi Alec, I'm trying to achieve the latter. A user should be able to add custom instructions without having to touch the decoder.
Robert Am 14.02.2018 um 03:08 schrieb Alec Roelke: > Hi Robert, > > Are you trying to reduce compilation time of gem5 itself by bypassing the > decoder description, or are you trying to add the ability to specify custom > instructions in a simulation script so gem5 doesn't have to be recompiled > at all to add new ones? > > -Alec Roelke > > On Thu, Feb 8, 2018 at 10:34 AM, Robert Scheffel < > robert.scheff...@tu-dresden.de> wrote: > >> Hi all, >> >> as part of my diploma thesis I want to implement an interface for custom >> instructions for the RISC-V ISA. >> The goal is to have a mechanism (plug-in, ...) where a user can easily add >> an instruction, define its opcode and its behaviour without touching the >> decoder. >> >> As changing the underlying decoder results in recompiling and rebuilding >> of almost the whole binary, I think it might be better to define entry >> points in the decoder that give control to a decoding function within a >> plug-in. >> This way the decoder doesn't need to be touched, when a new instruction is >> added. >> A first idea, that comes to my mind, is to describe the behaviour and >> opcodes in a C++ file. From all existing descriptions a custom decoder is >> generated, that takes over decoding, once the gem5 decoder reaches the >> entry point for custom instructions. >> >> Do you see any problem with this approach? Is there a better way to >> implement such an interface? >> >> Kind regards >> >> Robert >> >> _______________________________________________ >> gem5-dev mailing list >> gem5-dev@gem5.org >> http://m5sim.org/mailman/listinfo/gem5-dev > _______________________________________________ > gem5-dev mailing list > gem5-dev@gem5.org > http://m5sim.org/mailman/listinfo/gem5-dev > _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
