[Buildroot] [PATCH 1/6] boot/arm-trusted-firmware: support 32bit Arm targets

Etienne Carriere etienne.carriere at linaro.org
Fri Mar 15 09:00:03 UTC 2019


On Thu, 14 Mar 2019 at 23:24, Thomas Petazzoni
<thomas.petazzoni at bootlin.com> wrote:
>
> Hello,
>
> On Wed,  6 Mar 2019 11:11:35 +0100
> Etienne Carriere <etienne.carriere at linaro.org> wrote:
>
> > This change allows one to build the TF-A (Trusted Firmware A) for
> > 32bit Armv7 and Armv8 platforms which arm-trusted-firmware supports
> > since release v1.5.
> >
> > BR2_aarch64 is changed to BR2_ARM_CPU_ARMV8A as the later complemented
> > by BR2_ARM_CPU_ARMV7A better represents to architectures that can
> > support Arm Trusted Firmware A.
> >
> > When BR2_arm is enabled, TF-A is built in Aarch32 mode.
> > Selection between Armv8-A (default) and Armv7-A (ARM_ARCH_MAJOR=7) is
> > expected from BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES.
>
> It seems a bit annoying to require passing ARM_ARCH_MAJOR=7 in those
> additional variable. Why don't we do it automatically in
> arm-trusted-firmware.mk. We have all the knowledge required, no?
>
> > +ifeq ($(BR2_arm),y)
> > +ARM_TRUSTED_FIRMWARE_MAKE_OPTS += ARCH=aarch32
>
> Can we do:
>
> ifeq ($(BR2_arm),y)
> ARM_TRUSTED_FIRMWARE_MAKE_OPTS += ARCH=aarch32 ARM_ARCH_MAJOR=7
> else
> ARM_TRUSTED_FIRMWARE_MAKE_OPTS += ARCH=aarch64 ARM_ARCH_MAJOR=8
> endif
>
> for example ?

Well... I guess yes. Until there comes Aarch32 Armv8-A platforms.
So, yes, you're right. Your change will relax ARM_ARCH_MAJOR from
..._ADDITIONAL_VARIABLES.

regards,
etienne

>
> Thomas
> --
> Thomas Petazzoni, CTO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com



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