[Qemu-discuss] qemu microblazeel system reboot does not work

[Waldemar Brodkorb]

Hi,

I am trying to implement a automatic testing framework for musl
libc¹ with help of qemu system emulation. It works so far for
arm/mips/mipsel/powerpc/x86/x86_64 architectures. Now I am working
on the microblaze/microblazeel support, and I have a system with
Linux 3.11.10 and Glibc 2.18, which boots up fine².

I am using qemu 1.7.0 and starting the system with
qemu-system-microblazeel -M petalogix-s3adsp1800 -kernel \
qemu-microblazeel-initramfs-piggyback-kernel \
-nographic -dtb qemu.dtb -no-reboot

The qemu.dtb is generated after modifying the original
petalogix-s3adsp1800.dts file via dtc³. I added the 
hard-reset-gpios value, which is used by the linux kernel
in arch/microblaze/kernel/reset.c to trigger a system reset
on real FPGA hardware. In Qemu the kernel just hangs without 
getting back to my shell.

My question is, what is the best way to implement the restart
functionality in Qemu? Are there any examples where other machine
emulations using GPIO for system reset/reboot?
Or do I misunderstood the problem and I have a configuration issue
in the DTS or kernel?

I also tried to run Xilinx modified version of Qemu with -M
microblaze-fdt and qemu.dtb, it bootups fine, but did not reboot
successfully. And finally I also tried Qemu from Labx
(https://github.com/labx-technologies-llc/mb-qemu-labx) without
success.

Thanks for any help.

best regards
 Waldemar

P.s.: qemu-microblazeel-initramfs-piggyback-kernel is linux.bin with
included initramfs. you can get it via:
http://www.openadk.org/qemu-microblazeel-initramfs-piggyback-kernel


¹ http://www.musl-libc.org/
² http://www.openadk.org/qemu-mbel.log
³ http://www.openadk.org/qemu.dts.diff
  http://www.openadk.org/qemu.dts