Enable arm_global_timer for Zynq brakes boot

[Sören Brinkmann]

On Tue, Aug 06, 2013 at 06:09:09PM +0200, Daniel Lezcano wrote:
> On 08/06/2013 03:18 PM, Michal Simek wrote:
> 
> [ ... ]
> 
> >>>>> Soren: Are you able to replicate this issue on QEMU?
> >>>>> If yes, it should be the best if you can provide Qemu, kernel .config/
> >>>>> rootfs and simple manual to Daniel how to reach that fault.
> >>>>
> >>>> I tried to download qemu for zynq but it fails:
> >>>>
> >>>> git clone git://git.xilinx.com/qemu-xarm.git
> >>>> Cloning into 'qemu-xarm'...
> >>>> fatal: The remote end hung up unexpectedly
> >>>
> >>> Not sure which site have you found but
> >>> it should be just qemu.git
> >>> https://github.com/Xilinx/qemu
> >>>
> >>> or github clone.
> >>
> >> Ok, cool I was able to clone it.
> >>
> >>>> I am also looking for the option specified for the kernel:
> >>>>
> >>>> "The kernel needs to be built with this feature turned on (in
> >>>> menuconfig, System Type->Xilinx Specific Features -> Device Tree At
> >>>> Fixed Address)."
> >>
> >> Ok.
> >>
> >>> This also sound like a very ancient tree.
> >>> This is the latest kernel tree - master-next is the latest devel branch.
> >>> https://github.com/Xilinx/linux-xlnx
> >>
> >> Ok, cool. I have the right one.
> 
> Following the documentation, I was able to boot a kernel with qemu for
> the linux-xlnx and qemu-xilinx.
> 
> But this kernel is outdated regarding the upstream one, so I tried to
> boot a 3.11-rc4 kernel without success, I did the following:
> 
> I used the default config file from linux-xlnx for the upstream kernel.
> 
> I compiled the kernel with:
> 
> make -j 5 ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-
> UIMAGE_LOADADDR=0x8000 uImage
> 
> I generated the dtb with:
> 
> make -j 5 ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- dtbs
> 
> For qemu, I started qemu with:
> 
> ./arm-softmmu/qemu-system-arm -M arm-generic-fdt -nographic -smp 2
> -machine linux=on -serial mon:stdio -dtb zynq-zed.dtb -kernel
> kernel/zImage -initrd filesystem/ramdisk.img
> 
> I tried with the dtb available for the upstream kernel:
> 
> zynq-zc706.dtb, zynq-zc702.dtb and zynq-zed.dtb
> 
> Did I miss something ?

Some debugging hints in case you wanna go through this.
Add this additional option to configure:
 --extra-cflags="-DFDT_GENERIC_UTIL_ERR_DEBUG=1

That'll print out a lot of messages when the dtb is parsed. It's likely
that QEMU invalidates some vital node due to its compatible string being
unknown. In that case you can simply add it to the list of known devices
in 
	hw/core/fdt_generic_devices.c
The list is pretty much at the end of that file. I try to get it running
here and might be able to send you a patch.

	Sören