[Aboriginal] Aboriginal for Cortex-A15

[Rob Landley]

On 05/30/2016 02:00 AM, Baumann, Christoph (C.) wrote:
> Hello!
> 
> As currently Aboriginal has no target definition for ARMv7 (Cortex-A15 to be more precise),

The toolchain we're using is the last GPLv2 release, and that only had
armv6. We updated the binutils to the last version out of git before the
license switch, which does have armv7 support, but the kernel build gets
confused.

I hope to move the project to LLVM, but it's not quite ripe yet.

> I started setting it up myself.
> Compilation succeeds, but so far the resulting image wouldn't boot at all.
> QEMU crashes even before trying to start the kernel: "PFLASH: Possible BUG
> - Write block confirm".
> The qemu command used is this:
> qemu-system-arm -m 1024M -M vexpress-a15 -serial stdio -cpu cortex-a15 -nographic -no-reboot -kernel linux -initrd rootfs.cpio.gz -append "mem=1024M panic=1 HOST=armv7lhf $KERNEL_EXTRA" $QEMU_EXTRA
>
> As kernel config I used arch/arm/configs/vexpress_defconfig.

I haven't tried that one, but in general the kernel's gcc feature probes
of the old toolchain's capabilities and what features it tries to select
don't agree. (And sometims fail silently.)

> Any hints or ideas?

Tristan Van Berkholm has a fork with GPLv3 licensed gcc/binutils versions:


http://lists.landley.net/htdig.cgi/aboriginal-landley.net/2016-February/001584.html

I also note that you can build an armv5l or armv6l root filesystem and
use a different toolchain to build your kernel. (I have qemu using the
external initramfs load support by default, so building cpio and vmlinux
separately should work fine.)

Rob