SoCFPGA with CONFIG_THUMB2_KERNEL boot error

[Sascha Hauer]

On Wed, Apr 20, 2016 at 12:26:22PM +0200, Ard Biesheuvel wrote:
> On 20 April 2016 at 11:55, Sascha Hauer <s.hauer at pengutronix.de> wrote:
> > On Wed, Apr 20, 2016 at 11:43:30AM +0200, Ard Biesheuvel wrote:
> >> (replying to self)
> >>
> >> On 20 April 2016 at 11:39, Ard Biesheuvel <ard.biesheuvel at linaro.org> wrote:
> >> > (+ Arnd)
> >> >
> >> > On 20 April 2016 at 11:25, Dave Martin <Dave.Martin at arm.com> wrote:
> >> >> On Tue, Apr 19, 2016 at 04:02:20PM +0200, Steffen Trumtrar wrote:
> >> >>> Hi!
> >> >>>
> >> >>> According to kernelci.org (and validating on my own hardware), the current
> >> >>> socfpga mainline kernel has an issue with CONFIG_THUMB2_KERNEL enabled.
> >> >>>
> >> >>> https://storage.kernelci.org/mainline/v4.6-rc4-11-g12566cc35d0e/arm-multi_v7_defconfig/lab-khilman/boot-socfpga_cyclone5_de0_sockit.html
> >> >>>
> >> >>> vs
> >> >>>
> >> >>> https://storage.kernelci.org/mainline/v4.6-rc4-11-g12566cc35d0e/arm-multi_v7_defconfig+CONFIG_THUMB2_KERNEL=y/lab-khilman/boot-socfpga_cyclone5_de0_sockit.html
> >> >>>
> >> >>> Both boot successfully, but notice that the board fails to bring up CPU1 if
> >> >>> thumb2 support is enabled.
> >> >>>
> >> >>> Any ideas why this might be happening?
> >> >>
> >>
> >> Actually, this looks like a problem with the secondary entry point to
> >> me. Could you try this?
> >
> > Been there, done that. Unfortunately this does not solve the problem.
> >
> 
> How about if you put this on top?
> 
> diff --git a/arch/arm/mach-socfpga/headsmp.S b/arch/arm/mach-socfpga/headsmp.S
> index 5d94b7a2fb10..c160fa3007e9 100644
> --- a/arch/arm/mach-socfpga/headsmp.S
> +++ b/arch/arm/mach-socfpga/headsmp.S
> @@ -13,6 +13,7 @@
>  #include <asm/assembler.h>
> 
>         .arch   armv7-a
> +       .arm

\o/

This did the trick, it now boots with two cpus up. Thanks for looking
into this issue.

I'll create a patch for this.

Sascha

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