Re: Firefox crashes all the time on the RaspBerry Pi Zero 2W

On Apr 13, 2025, at 09:41, Mark Millard <[email protected]> wrote:

> On Apr 13, 2025, at 04:20, Andrew Haley <[email protected]> wrote:
> 
>> On 13/04/2025 11:51, Ronald Klop wrote:
>>> Op 29-03-2025 om 23:31 schreef Mario Marietto:
>>>> Hello to everyone.
>>>> 
>>>> I've installed FreeBSD 14.2 on my Raspberry Pi Zero 2W.
>>>> The problem that I'm having is that Firefox crashes all the time. The errors that it gives are :
>>>> 
>>> The warnings  Firefox is printing might be misleading. The most concrete thing it says is "Segmentation fault (core dumped)". So you could look up the core dump and use a debugger to check what is going on. As Firefox is a big piece of software this might not be trivial.
>> 
>> Is this a 64-bit build?
>> 
>> Some early revisions of the Cortex-A53 have an erratum (835769) whereby
>> it is possible for a 64-bit multiply-accumulate instruction in
>> AArch64 state to generate an incorrect result.  The details are quite
>> complex and hard to determine statically, since branches in the code
>> may exist in some circumstances, but all cases end with a memory
>> (load, store, or prefetch) instruction followed immediately by the
>> multiply-accumulate operation.
>> 
>> Cortex-A53_MPCore_Software_Developers_Errata_Notice_21.pdf
>> https://gcc.gnu.org/legacy-ml/gcc-patches/2014-10/msg00906.html
>> 
>> To work on these computers, all software must be compiled with the
>> -mfix-cortex-a53-835769 compiler option.
>> 
>> We have seen this crash in the wild.
>> 
> 
> On a Zero 2 W? That was released in 2021-Oct. The RPi3B was
> released in 2016-Feb. The errata with 835769 was published
> in the 2014-Oct-08 ARM-EPM-048406 v14 document.
> 
> There is also 843419 from the 2015-Feb-20 ARM-EPM-048406 v16
> document. And there are others.
> 
> Looking at what FreeBSD reports for the r0p? revision would
> be relevant to what REVIDR register bits might report about
> the status of such errata for a Cortex-A53.
> 
> r0p0:
> REVIDR[0] 810919 CatB Clearing of the global exclusive monitor can fail to set the event register 
> REVIDR[1] 812869 CatA Instruction stream might be corrupted 
> 
> r0p1:
> REVIDR[2] 821523 CatA Hazarding snoop request might cause deadlock 
> REVIDR[6] 829070 CatA Speculative data reads might be performed to Device memory 
> 
> r0p2:
> REVIDR[2] 821523 CatA Hazarding snoop request might cause deadlock 
> REVIDR[4] 823273 CatA Rare Load or store which fails condition code check might cause data corruption
> REVIDR[5] 823819 CatB A snoop request to a core coincident with retention entry might cause deadlock
> REVIDR[6] 829070 CatA Speculative data reads might be performed to Device memory
> REVIDR[7] 835769 CatA AArch64 multiply-accumulate instruction might produce incorrect result
> 
> r0p3:
> REVIDR[6] 829070 CatA Speculative data reads might be performed to Device memory 
> REVIDR[7] 835769 CatA AArch64 multiply-accumulate instruction might produce incorrect result 
> 
> r0p4:
> REVIDR[7] 835769 CatA AArch64 multiply-accumulate instruction might produce incorrect result 
> REVIDR[8] 843419 CatA A load or store might access an incorrect address
> REVIDR[9] 859374 CatC AArch64 memory streaming performance might be lower than expected when using a 64KB translation granule
> 
> Does anything report the Cortex-A53 REVIDR value as well?
> 

I looked at a old serial console capture of a boot log from
a very old RPi3B. It showed r0p4:

CPU  0: ARM Cortex-A53 r0p4 affinity: 

But I did not see anything that looked to be based on REVIDR.

===
Mark Millard
marklmi at yahoo.com