[Buildroot] [PATCH] ARC: allow selection of MMU page size
Arnout Vandecappelle
arnout at mind.be
Thu Jul 16 22:40:20 UTC 2015
On 07/16/15 21:04, Alexey Brodkin wrote:
> Modern ARC cores (those sporting MMU of version 3 and 4) allow selection
> of different page sizes (4, 8 or 16 kB) during ASIC design creation.
> And it's important to build a toolchain with page size setting that matches
> hardware.
>
> Otherwise user-space applications will fail on execution due to
> unexpected data layout/alignment etc.
>
> Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
> c: Anton Kolesov <akolesov at synopsys.com>
> Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
> arch/Config.in.arc | 30 ++++++++++++++++++++++++++++++
> package/uclibc/uclibc.mk | 8 ++++++++
> 2 files changed, 38 insertions(+)
>
> diff --git a/arch/Config.in.arc b/arch/Config.in.arc
> index b48a90f..e960eb8 100644
> --- a/arch/Config.in.arc
> +++ b/arch/Config.in.arc
> @@ -40,3 +40,33 @@ config BR2_GCC_TARGET_CPU
> default "arc700" if BR2_arc750d
> default "arc700" if BR2_arc770d
> default "archs" if BR2_archs38
> +
> +choice
> + prompt "MMU Page Size"
It is not really current policy, but wouldn't it make more sense to do
prompt "MMU Page Size" if BR2_arc770d || BR2_archs38
? (i.e., only show it when there's anything to choose).
Also perhaps it makes sense to add a new symbol
BR2_ARC_SUPPORTS_PAGE_SIZE_SELECTION or similar instead of specifying the
individual processors.
Regards,
Arnout
> + default BR2_arc_page_size_8k
> + help
> + MMU starting from version 3 (could be found in ARC 770) and now
> + version 4 (could be found in ARC HS38) allows selection of page
> + size during ASIC design creation. And it's important to build
> + a toolchain with page size setting that matches hardware.
> + Otherwise user-space applications will fail on execution due to
> + unexpected data layout/alignment.
> +
> +config BR2_arc_page_size_4k
> + bool "4KB"
> + depends on BR2_arc770d || BR2_archs38
> +
> +config BR2_arc_page_size_8k
> + bool "8KB"
> +
> +config BR2_arc_page_size_16k
> + bool "16KB"
> + depends on BR2_arc770d || BR2_archs38
[snip]
--
Arnout Vandecappelle arnout at mind be
Senior Embedded Software Architect +32-16-286500
Essensium/Mind http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium BE 872 984 063 RPR Leuven
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