wandboard SMP panic

[Andrew Turner]

On Sat, 23 Aug 2014 18:57:57 -0600
Tom Everett <tom at 0x544745.com> wrote:

> 
> Hello everyone.  I am seeing a new panic booting Wandboard:
> 
> Loaded DTB from file 'wandboard-quad.dtb'.
> 
> 
> Kernel entry at 0x12000100...
> 
> 
> Kernel args: (null)
> 
> 
> KDB: debugger backends: ddb
> KDB: current backend: ddb
> Copyright (c) 1992-2014 The FreeBSD Project.
> Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993,
> 1994 The Regents of the University of California. All rights reserved.
> FreeBSD is a registered trademark of The FreeBSD Foundation.
> FreeBSD 11.0-CURRENT #0 r270430M: Sat Aug 23 17:24:21 MDT 2014
>      
> tom at bernice:/storage/home/tom/crochet/crochet-freebsd/work/obj/arm.armv6/storage/home/tom/crochet/src/FreeBSDHead/head/sys/IMX6 
> arm
> FreeBSD clang version 3.4.1 (tags/RELEASE_34/dot1-final 208032)
> 20140512 CPU: Cortex A9-r2 rev 10 (Cortex-A core)
>   Supported features: ARM_ISA THUMB2 JAZELLE THUMBEE ARMv4
> Security_Ext WB disabled EABT branch prediction enabled
> LoUU:2 LoC:1 LoUIS:2
> Cache level 1:
>   32KB/32B 4-way data cache WB Read-Alloc Write-Alloc
>   32KB/32B 4-way instruction cache Read-Alloc
> real memory  = 2147483648 (2048 MB)
> avail memory = 2093891584 (1996 MB)
> WARNING: Some AP's failed to start
> FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
> random device not loaded; using insecure entropy
> panic: Built bad topology at 0xc2510fb4.  CPU mask (f) != (1)
> cpuid = 0
> KDB: enter: panic
> [ thread pid 0 tid 100000 ]
> Stopped at      $d:     ldrb    r15, [r15, r15, ror r15]!
> db>

I had a similar problem. It turned out to be a caching issue in U-Boot.
It appears to not correctly flush the dcache. You can try to run
"dcache off ; dcache flush" before entering ubldr. If this fails you
will need to build a version of U-Boot with the dcache disabled.

Andrew