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

Peter Korsgaard
2016-12-11T20:01:59Z

>>>>> "Afzal" == Afzal Mohammed <afzal.mohd.ma@gmail.com> 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.

--
Bye, Peter Korsgaard