Hi Florian,

quoted

I think it is fine to only target ARMv7. It is harder and harder to
find devices on v5 or v6 CPUs that would want to be using BPF JIT,
IMO.

There are still a ton of Marvell-based routers out there (e.g: Kirkwood,
Orion5x) that are ARMv5 and that prompted Nicholas (hey there) to fix
the cBPF JIT a while ago. I don't think you can just ignore those, it's
fine not to target them initially, but arguably, QEMU has decent support
for some ARMv5 platforms that could be used for testing as well
(realview-eb, versatileab/pbm.

I am using busybox to get the rootfs. Here is what I am doing :-

1. ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make -j4 (for kernel
build as well as busybox build)
2. qemu-system-arm -M vexpress-a9 -dtb
./linux/arch/arm/boot/dts/versatile-ab.dts -kernel ./linux/arch/a
rm/boot/zImage -append "root=/dev/mmcblk0 console=ttyAMA0" -sd
./a9rootfs.ext3 --nographic

Can you help me with running qemu for ARMv5 and ARMv6 ?

quoted

When they "disappear", it's because there isn't a prerequisite met. I
either read the Kconfig files or use "make menuconfig" and "search" to
tell me where a config is defined and what is needed to meet the
prerequisites.

In the case of CPU_BIG_ENDIAN, you need ARCH_SUPPORTS_BIG_ENDIAN,
which appears to be only ARCH_IXP4XX. I don't think you're going to
find an emulator that will handle this, so I'd suggest ignoring this
config for now unless you can find someone with that hardware that you
can work with to test it.

In the case of CONFIG_FRAME_POINTER, I assume you built a
THUMB2_KERNEL? I'd read the notes in arch/arm/Kconfig.debug for
'config FRAME_POINTER'.

It sounds like we are at the point where Shubham's patches should be
posted so people could test/fix on earlier ARM devices for instance.

I would post them as soon as I test them on ARMv5 and ARMv6. If you
can help me with that, please let me know.

Thanks
--
Florian

-Shubham