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riscv / configuration-structure

RISC-V Configuration Structure
https://jira.riscv.org/browse/RVG-50
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Questions or clarifications on configuration structure yaml and schema #106

Open swarajIMG opened 2 years ago

swarajIMG commented 2 years ago

Hi,

There are a few questions/issues formulating the configuration structure yaml.

  1. The schema has a TODO against trace actions 2-4. The intention is to use traceOnSupported, traceOffSupported, traceNotifySupported. Can you let us know if this is alright?

  2. The schema has icount, itrigger, etrigger and mcontrol6 to be optional. Not mentioning any of these would mean its not supported?

  3. haltGroupCount and resumeGroupCount support values of integer 1 to 31 in the schema. Absence of halt group and resume group would need them to be 0. Is it a schema issue?

  4. How do we imply that the Quick Access Command is not supported in the yaml? I see in the schema that QuickAccessCommand ::= SEQUENCE { supported = NULL, …}

  5. If the dscratch registers are not implemented, the hartinfo will have nscratch to be 0 and dataaccess in yaml to be none: NULL. Does that sound right?

Thanks in advance for your help.

Regards, Swaraj

timsifive commented 2 years ago

configuration-structure is not yet ratified, and might see dramatic changes before that happens. I would caution against implementing it already, but feedback is still appreciated.

  1. You can't add your own guesses to the schema that you yourself use. Unless you happen to guess exactly what will be in the future spec, it will be incompatible. Having said that, your suggestion makes sense, and if you make a PR for the change I'll probably merge it.
  2. Yes. In general for the schema, things that aren't mentioned are not supported.
  3. These values are optional, so when they're not supported then they are omitted from the description.
  4. quickAccessCommand is an optional sequence, so you can omit it altogether.
  5. Yes, that sounds right.