CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS and bcm2835_defconfig

[Vince Weaver]

On Wed, 12 Mar 2014, Vince Weaver wrote:

> On Wed, 12 Mar 2014, Will Deacon wrote:
> > 
> > I just took the tree you mentioned above, merged together 3.14-rc6,
> > for-3.15/soc and for-3.15/dt. Using the defconfig (+ appended dtb options)
> > and cross-compiling with a dated linaro toolchain, it booted fine on my rpi:
> > 
> >   Uncompressing Linux... done, booting the kernel.
> >   [    0.000000] Booting Linux on physical CPU 0x0
> >   [    0.000000] Initializing cgroup subsys cpuset
> >   [    0.000000] Initializing cgroup subsys cpu
> >   [    0.000000] Initializing cgroup subsys cpuacct
> >   [    0.000000] Linux version 3.14.0-rc6+ (will at tiny-lites) (gcc version 4.8.2 20130603 (prerelease) (crosstool-NG linaro-1.13.1-4.8-2013.06 - Linaro GCC 2013.06) ) #8 Wed Mar 12 10:51:44 GMT 2014
> >   [    0.000000] CPU: ARMv6-compatible processor [410fb767] revision 7 (ARMv7), cr=00c5387d
> >   [    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT nonaliasing instruction cache
> >   [    0.000000] Machine model: Raspberry Pi Model B
> >   [    0.000000] bootconsole [earlycon0] enabled
> >   [    0.000000] Memory policy: Data cache writeback
> >   [    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 97536
> >   [...]
> > 
> > Which compiler are you using?
> 
> it's the gcc 4.6.3 that comes with the version of raspian on the rasp-pi 
> (I'm compiling natively).  Let me try again and double check there weren't 
> any other changes.

I re-built from scratch using the bcm2835_defconfig and again it hangs at 
boot, actually it looks like it hangs just after

	Uncompressing Linux...

on the serial console.

The only difference in .config between a working config and the hanging 
one are
	CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
	CONFIG_ARCH_USE_BUILTIN_BSWAP

Unfortunately my machine is remote and I won't be able to get in and 
reboot it and do more testing until probably Friday.

Vince