Re: [Milkymist port] virtual memory management

[Yann Sionneau <yann.sionneau%gmail.com@localhost>]

Le 10/02/14 23:00, Yann Sionneau a écrit :
> Thanks for all your explanations, if everything I said here is correct 
> (which would mean I understood correctly your answer) then I think I'm 
> ready to implement all this :)

Hi,

I have made good progress on the NetBSD port, it is now booting up to 
enabling interrupts and cpu_initclocks() call, see the boot log [0].

But then I am wondering how I can map the memory mapped registers of the 
timer0 of Milkymist SoC in order to use it as the main ticking clock.

Basically, I need to map physical address 0xe000.1000 somewhere in 
kernel virtual memory.

Is there somewhere a function like vaddr_t map_paddr(paddr_t, prot)?

I could indeed walk the kernel page table and insert somewhere in a free 
PTE (a NULL one) a reference to the 0xe000.1000 physical address, but 
then how to be sure that the vm subsystem will not allocate this virtual 
address twice?

Is there an "iomapping" mechanism?

Thank you for your help :)

[0] -- http://pastebin.com/MYitt9L4

Best regards,

--
Yann Sionneau