Re: Unix platform working group future agenda (to be discussed in next meeting (06/09 8AM PST))
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One additional topic: All the various architecture specs have little to lots of optional features or parameters that can be implementation-specific. Some of these probably want to have minimum requirements specified in the Linux platform spec (similar to what the ARM SBSA does, for example). For example:
A minimum reservation set size for LR/SC.
Minimum supported ASID size.
Minimum number and width of hardware performance counters. Support for the small set of standard Linux perf mon events.
If the Hypervisor extension is supported:
Minimum supported VMID size
Full support for CSR's like htval and htinst
Past RV64GC, what other extensions should be required? For example, the BitManip Zba/Zbb/Zbs extensions (and maybe Zbc) have value for general compiled code? In the future the hypervisor and vector extensions probably want to become a requirement (but as say part of a future next "level" of platform spec).
Minimum and recommended mtime frequency.
Standard system watchdog timer?
Standard system UART for early boot communication.
The Debug spec (which provides facilities for self-hosted as well as external debug) has most features as optional. At least for self-hosted debug purposes, should there be a minimum set of trigger module requirements for how many triggers and what trigger features are available?
Presenting on-chip peripherals as PCIe integrated endpoints? (SBSA provides a lot of standardization along these lines. But this may be a bridge too far at this early stage of platform standardization.)
On Tue, Jun 2, 2020 at 6:08 PM Atish Patra <atish.patra@...> wrote: