[yocto] [meta-raspberrypi] poky linux build fails if ARM erratum mfix linker switch is specified

[Adrian Bunk]

On Mon, Nov 04, 2019 at 10:48:57AM -0500, Steve Pavao wrote:
> 
> > On Nov 3, 2019, at 1:25 PM, Adrian Bunk <bunk at stusta.de> wrote:
> > 
> > On Sun, Nov 03, 2019 at 05:56:45PM +0000, Andrei Gherzan wrote:
> >> On 3 November 2019 13:18:53 GMT, Khem Raj <raj.khem at gmail.com> wrote:
> >>> On Sun, Nov 3, 2019 at 2:46 AM Andrei Gherzan <andrei at gherzan.ro>
> >>> wrote:
> >>>> I was thinking about this. The erratum seems to show that this
> >>> applies
> >>>> to all revisions of a53. So it sounds like we should add it in
> >>>> `tune-cortexa53.inc`.
> >>>> 
> >>> 
> >>> Up to r0b4 only so maybe not all a53 implementations are impacted
> >>> 
> >> 
> >> As far as I know that is the latest revision. Do you mean that newer revision might come up with this fixed? 
> > 
> > It is fixed in some r0p4 implementations, indicated in REVIDR[8].
> 
> I am closer to understanding why I experience an error when building with the ARM errata switches.
> 
> I believe it is related to 32-bit app support in my poky Linux 64-bit build (I add this to support vcgencmd and vcdbg 32-bit apps.)
> 
> When I remove the 32-bit support, the build completes OK.  As of now, adding the following seems to work fine to acheive this:
> 
> TARGET_CC_ARCH_append += " -mfix-cortex-a53-843419 -mfix-cortex-a53-835769”
> 
> Something in the following block seems to be the culprit.:
> 
> # for vcgencmd and vcdbg 32-bit executable support in the OS image (comment out for -c populate_sdk)
> require conf/multilib.conf
> MULTILIBS = "multilib:lib32"
> DEFAULTTUNE_virtclass-multilib-lib32 = "armv7a"
> IMAGE_INSTALL_append += " vcgencmd lib32-glibc lib32-libgcc lib32-libstdc++ vcdbg rpi-setup \
> “
> 
> I will post again when I have localized the build problem further.  Maybe there’s some 64-bit vs. 32-bit build confusion going on, and the armv7a default tune switch for 32-bits is colliding with the errata switches.

The errata switches are only valid for aarch64, not for armv7a.
There is likely some kind of "invalid option" earlier in your build.

> - Steve Pavao
> Korg R&D

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed