[RFC v3 PATCH 00/25] Allow NOMMU for MULTIPLATFORM

Hi all,

  You can find an R toolchain here:
https://github.com/mickael-guene/fdpic_manifest/releases/download/v7-r-1.0.1/toolset-v7-r-1.0.1-0-gbdcc6a7c-armv7-r.tgz

  It's an fdpic toolset for cortex-r cpu class. gcc version is
quite old (4.7).

  Note also that generated code may crash on class A cpu due to
generation of udiv/sdiv which is optional for class A.
(cortex a15 is ok but not a9).

Hope it helps

Regards
Mickael

On 12/11/2016 09:01 PM, Peter Korsgaard wrote:

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"Afzal" == Afzal Mohammed [off-list ref] writes:

Hi,

 >> You can build a toolchain and initramfs with Buildroot. Have a look at
 >> the stm32f429 nommu config:
 >>
 >> https://git.buildroot.net/buildroot/tree/configs/stm32f429_disco_defconfig

 > iiuc, it builds one for Cortex-M. i already had a file system w/
 > busybox compiled using a Cortex-M toolchain (stolen from
 > Pengutronix's OSELAS.Toolchain), which works on Cortex M4 (Vybrid
 > VF610 M4 core). But it does not work here, i.e. on Cortex A, seems the
 > above mentioned also would have the same effect.

Hmm, I'm not sure why a cortex-M toolchain wouldn't work on cortex-A, I
thought the 'M' instruction set was a pure subset of the 'A'.

 > And in buildroot, couldn't see Cortex R option in menuconfig, and
 > selecting Cortex-A's excludes flat binary target & presents only with
 > ELF.

We indeed don't have cortex-R support. I'm not aware of any cortex-R
Linux support.

When you select a cortex-A variant, then we enable MMU support by
default, but you can disable it under toolchain options (Enable MMU) and
then the flat binary option is available.