Re: [PATCH 06/28] nios2: Memory management

From: Ezequiel Garcia
Date: Tue Apr 22 2014 - 12:28:37 EST


On Apr 23, Chung-Lin Tang wrote:
> On 2014/4/22 äå 11:35, Ezequiel Garcia wrote:
> > On Apr 22, Tobias Klauser wrote:
> >> On 2014-04-22 at 16:24:43 +0200, Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx> wrote:
> >>> Hi Ley Foon,
> >>>
> >>> On Apr 18, Ley Foon Tan wrote:
> >>>> +/*
> >>>> + * PAGE_SHIFT determines the page size
> >>>> + */
> >>>> +#define PAGE_SHIFT 12
> >>>> +#define PAGE_SIZE 4096
> >>>> +#define PAGE_MASK (~(PAGE_SIZE - 1))
> >>>> +
> >>>
> >>> How about something like this:
> >>>
> >>> /* PAGE_SHIFT determines the page size */
> >>> #define PAGE_SHIFT 12
> >>> #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
> >>> #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
> >>>
> >>> Otherwise, the PAGE_SIZE macro above produces some warnings, IIRC.
> >>
> >> AFAIR old nios2 GCC versions (the 4.1 version from Windriver, IIRC)
> >> would complain about something like the above, that's the reason I added
> >> an explicit value for PAGE_SIZE back then.
> >>
> >
> > Other than being "pretty" the above fix is to remove a mismatch type
> > warning. You can get rid of the warning in different ways:
> >
> > ifdef __ASSEMBLY__
> > define PAGE_SIZE 4096
> > else
> > define PAGE_SIZE 4096UL
> > endif
> >
> >> I assume with the new nios2 GCC this should no longer be necessary and
> >> Ezequiel's fix should be fine.
> >
> > Speaking of GCC... is there a libc available to test this kernel port?
> > (which I assume uses the generic syscall ABI)
>
> It's submitted to libc-alpha, also still review in progress.
>

Do you plan to support uclibc?

--
Ezequiel GarcÃa, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
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