Re: [lowrisc-dev] What is your opinion about RISCV priv. spec 1.9.1 ?
On 9 November 2016 at 10:04, Reinoud Zandijk <reinoud(a)netbsd.org> wrote:
Dear folks,
the title asks the question already: what do you like or dislike of the RISCV
priv. spec 1.9.1 as posted. What parts would you do different or what ideas
really ought to go but also what parts do you really like in it?
This is certainly a very broad question. I've never been a believer in
config-string (at least, until better motivation than device tree's
big-endian encoding is given) and have been following recent
discussion. I'm starting to understand why people are pushing for it,
but given the requirement for compatibility with the devicetree scheme
I worry there is so little room to diverge from the established
device-tree standard that config-string won't really have a
significant advantage over DT.
I have wondered whether it would make sense to iteratively approve the
specification, so that the most important parts to e.g. run Linux can
be standardised sooner rather than later - e.g. have the Foundation
standardise the PLIC and page table format asap, then take longer to
argue about the SBI, efficient virtualisation support etc. Perhaps it
just can't be split up, but the fact it's so expansive is going to be
a real test for the RISC-V standards approval process.
I think it might be worth having more recommendations for implementers
as part of the platform specification, even to the point of having a
recommended (but of course not required) memory map for a typical
Linux-capable system.
What are your thoughts Reinoud?
Best,
Alex