Re: [PATCH v7] RISC-V: enable XIP

From: David Hildenbrand
Date: Fri Apr 09 2021 - 08:46:30 EST


Also, will that memory properly be exposed in the resource tree as
System RAM (e.g., /proc/iomem) ? Otherwise some things (/proc/kcore)
won't work as expected - the kernel won't be included in a dump.
Do we really need a XIP kernel to included in kdump?
And does not it sound weird to expose flash as System RAM in /proc/iomem? ;-)

See my other mail, maybe we actually want something different.


I have just checked and it does not appear in /proc/iomem.

Ok your conclusion would be to have struct page, I'm going to implement this
version then using memblock as you described.

I'm not sure this is required. With XIP kernel text never gets into RAM, so
it does not seem to require struct page.

XIP by definition has some limitations relatively to "normal" operation,
so lack of kdump could be one of them.

I agree.


I might be wrong, but IMHO, artificially creating a memory map for part of
flash would cause more problems in the long run.

Can you elaborate?


BTW, how does XIP account the kernel text on other architectures that
implement it?

Interesting point, I thought XIP would be something new on RISC-V (well, at least to me :) ). If that concept exists already, we better mimic what existing implementations do.

--
Thanks,

David / dhildenb