On Fri, Sep 5, 2014 at 7:42 PM, Matt Thomas <[email protected]> wrote: > > Having a syscall number is l.sys isn't that useful since you need to fetch > the instruction to read it. > If l.sys could place it in the EEAR SPR so the syscall handler could fetch it > would allow skipping of > loading the syscall number in a register.
The immediate in the l.sys isn't very useful, no. I suspect it was thrown in there since the space was unused anyway, but afaik no-one has ever used that. Storing the immediate into EEAR SPR is an interesting idea, and while that is worth considering to add to the arch spec (it doesn't break anything), depending on it will of course limit you to implementations post that version of the spec. Stefan _______________________________________________ OpenRISC mailing list [email protected] http://lists.openrisc.net/listinfo/openrisc
