CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS and bcm2835_defconfig

[Stephen Warren]

On 03/10/2014 03:21 PM, Vince Weaver wrote:
> Hello
> 
> I buit the current
> 	git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-rpi.git
> kernel on a Raspberry Pi.
> 
> I used 
> 	make bcm2835_defconfig
> 	make zImage
> but the results zImage hung at boot.
> 
> It turned out that for some reason 
> 	CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
> and
> 	CONFIG_ARCH_USE_BUILTIN_BSWAP=y
> 
> were enabled.  Once I disabled them and re-built, the kernel booted fine 
> (USB and ethernet worked too!).
> 
> I'm not sure if this is a bcm2835_defconfig issue or something that's 
> wrong with the generic upstream kernel config...

I think this is indeed wrong. I'll try investigating tonight.

What compiler/toolchain are you using to build the kernel? I haven't
seen any issue using the ARM cross-compilers that are packaged by amd64
Ubuntu.