Emulation of polarfire icicle board (riscv) and HSS

[Alexander V. Nikolaev]

Hello!

I tried to run qemu with following options:

$ qemu-system-riscv64 -M microchip-icicle-kit -smp 5 -m 4G \
  -bios ../hart-software-services/Default/hss-envm-wrapper.bin \
  -sd nixos.img -display none -serial stdio -D debug.log -d exec,in_asm,cpu

But got no output (except notice about raw image), I expect to get HSS messages 
on stdout.
debug.log shows that few commands executed, then all CPU stopped.

Could anyone hint me, what I missed. I tried different HSS versions (built by 
recommended compiler
as well as nixos' provided cross-compiler), neither of them didn't works.

Could someone share working command line and if possible a working HSS image as 
well.

Many thanks,
Alex.