[lowrisc-dev] Address bit width

Francesco Viggiano francesco.vgg at gmail.com
Thu Jul 14 21:30:09 BST 2016


Oh I'm sorry Wei, I meant the variable PAddrBits in Configs.scala . By the
way I'm not using an up-to-date version of lowRISC.

Francesco

On Thu, Jul 14, 2016 at 1:19 PM Wei Song <ws327 at cam.ac.uk> wrote:

> Hello Francesco,
>
> I did not find this pALen variable in current Configs.scala.
> However, even you managed to change this, it would not work.
> The current Rocket chip uses Sv39 address model by default, that means
> 39-bit physical address using 3-level page tables.
> I think it is much more possible to expand the physical address width to
> 39 and work out-straight.
> More than 39, it will need some significant changes.
>
> -Wei
>
> On 14/07/2016 13:06, Francesco Viggiano wrote:
> > Hello guys,
> >
> > Do you support 64 bit addresses in order to have a  total memory space
> > larger then 4 Gb? I see there is "pALen" variable in Configs.scala, if I
> > change that value to 64 the compilation get broken. Do I need to set
> other
> > parameters to accomplish that purpose?
> >
> > Bests,
> >
> > Francesco
>
> --
| Francesco Viggiano,  Columbia University, Staff associate researcher at
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