[Libre-soc-dev] SPRs used in microwatt

[Luke Kenneth Casson Leighton]

On 11/6/20, Tobias Platen <libre-soc at platen-software.de> wrote:
> today: first reading powerisa pdf and microwatt test program for mmu
> (tests/mmu/mmu.c)
>
> The following SPRs are used here:
> #define DSISR	18  //Data Storage Interrupt Status Register

don't know this one.

> #define DAR	19  //Data Address Register

or this.

> #define SRR0	26  //Save/Restore Register 0
> #define SRR1	27  //Save/Restore Register 1

know about these two, they're for context switches, to save MSR and PC (NIA)

> #define PID	48  //process ID

know about this one (or, can work it out)

> #define PRTBL	720 //process table -- this one does not appear in Power ISA
> Version 3.0B nor any later version

that's odd (interesting).  what _is_ at 720?

https://github.com/antonblanchard/microwatt/blob/master/decode1.vhdl#L586

ah they are all LDST related.

https://github.com/antonblanchard/microwatt/blob/e40e752b9ab602f5ce1eb79be1fe96932558830d/loadstore1.vhdl#L470

DSISR is related to cache errors

l.