QEMU localboot cannot see block devices

Hi team,
I got the complete build instructions working and able to run in qemu. I get as far as the "Systemboot" text art and then a boot loop starts. First fbnetboot is tried ( I don't have network configured ) and then sit0 and then localboot, which I am trying to get to work, by attaching an .iso as a cdrom device to the qemu command line.

madhan@madhan-HP-Notebook:~/coreboot$ sudo qemu-system-x86_64 -M q35 -enable-kvm -bios build/coreboot.rom -m 1024 -object rng-random,filename=/dev/urandom,id=rng0 -vga cirrus --serial /dev/tty -cdrom ./ubuntu-18.04.3-live-server-amd64.iso

However it seems like no block devices are seen. I tried attaching a scsi device, a block device and an usb device (all qcow2 image files that I could get to work in "HEADS" earlier) but same result. Also the uroot shell does not have lspci, lsmod, insmod etc. and so I am not able to look at the devices enumerated. But firstly, how do I know the tinylinux payload that we built got control or not? Should we dig into this on the uroot side or the tinylinux side? Any pointers please?

2019/12/02 16:02:19 Running boot command: [localboot -grub -d]
2019/12/02 16:02:19 Getting list of supported filesystems
2019/12/02 16:02:19 Supported file systems: [ext3 ext2 ext4 iso9660 udf]
2019/12/02 16:02:19 trying to mount all the available block devices with all the supported file system types
2019/12/02 16:02:19 mounted: []
2019/12/02 16:02:19 No boot configuration found
2019/12/02 16:02:19 Error executing &{/bbin/localboot [localboot -grub -d] []  <nil> 0xc00000e020 0xc00000e028 [] <nil> 0xc0000db2f0 exit status 1 <nil> <nil> true [0xc00000e148 0xc00000e020 0xc00000e028] [0xc00000e148] [] [] 0xc0000708a0 <nil>}: exit status 1

Thanks,
Madhan

Start with the QEMU command and the localboot log showing that no block devices were mounted, then determine whether the tinylinux payload received control. Investigate whether device enumeration belongs to uroot or tinylinux; the issue is resolved when the attached ISO or other block device is detected and localboot finds its boot configuration.