[PATCH 1/5] libmm score API

[Hesham Moustafa]

On Mon, Aug 26, 2013 at 8:21 PM, Gedare Bloom <gedare at rtems.org> wrote:

> On Mon, Aug 26, 2013 at 2:15 PM, Hesham Moustafa
> <heshamelmatary at gmail.com> wrote:
> >
> >
> >
> > On Mon, Aug 26, 2013 at 5:22 PM, Sebastian Huber
> > <sebastian.huber at embedded-brains.de> wrote:
> >>
> >> On 2013-08-26 02:14, Hesham AL-Matary wrote:
> >>>
> >>> +/**
> >>> + * @brief _Memory_management_Region Flags defs
> >>> + */
> >>> +#define RTEMS_MM_REGION_NO_PROTECTION           0x0
> >>> +#define RTEMS_MM_REGION_PROTECTION_READ_ONLY    0x1
> >>> +#define RTEMS_MM_REGION_PROTECTION_WRITE        0x2
> >>> +#define RTEMS_MM_REGION_NO_ACCESS               0x3
> >>> +//#define RTEMS_MM_REGION_PROTECTION_EXEC   0x4
> >>
> >>
> >> I prefer to actually have flags here and not a single integer value.
> >>
> >> So I would use this:
> >>
> >> #define RTEMS_MM_REGION_BIT_READ 0
> >> #define RTEMS_MM_REGION_BIT_WRITE 1
> >> #define RTEMS_MM_REGION_BIT_EXECUTE 2
> >> #define RTEMS_MM_REGION_BIT_CACHE 3
> >> #define RTEMS_MM_REGION_BIT_DEVICE 4
> >> #define RTEMS_MM_REGION_BIT_SHARED 5
> >>
> > Some of these flags are not supported on some architectures like
> > RTEMS_MM_REGION_BIT_SHARED, or targets that do not have
> > Cache Unit. How should we handle some of these flags for such
> > targets that do not support these features in hardware ?
> I would think the BSP will have to handle / ignore the attributes that
> do not make sense for it?
>
> I think of that solution too. But the developer may expect to apply this
attribute and wonder why it does not work as expected.

> >>
> >> #define RTEMS_MM_REGION_READ (1U << RTEMS_MM_REGION_BIT_WRITE)
> >> etc.
> >>
> >> This can be used to get architecture specific values easily:
> >>
> >> ((flags >> RTEMS_MM_REGION_BIT_READ) & 0x1U) << ARCH_READ_SHIFT
> >>
> > That make sense.
> >>
> >> --
> >> Sebastian Huber, embedded brains GmbH
> >>
> >> Address : Dornierstr. 4, D-82178 Puchheim, Germany
> >> Phone   : +49 89 189 47 41-16
> >> Fax     : +49 89 189 47 41-09
> >> E-Mail  : sebastian.huber at embedded-brains.de
> >> PGP     : Public key available on request.
> >>
> >> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
> >>
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> >
> >
> >
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>
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