Kernel Panic Unable to mount root fs on unknown-block(31,3)

[nada]

Using the latest qemu:
qemu-system-arm.exe -kernel C:\Users\a\Downloads\kernel-qemu-4.4.34-jessie -cpu arm1176 -m 256 -machine versatilepb -cdrom C:\Users\a\Downloads\picore-9.0.3.img

Gives error:
Kernel Panic Unable to mount root fs on unknown-block(31,3)

I have tried different ARMv6 ARMv7 images/kernels with the same result.

[Thomas Huth (th-huth)]

Did it work with a previous version of QEMU? If yes, which version? And since you're using -kernel ... don't you maybe have to use -initrd here, too?

[Peter Maydell (pmaydell)]

That's a guest error message, meaning it couldn't mount the root filesystem. This is almost certainly because you're not telling the guest kernel the right argument for where to find its rootfs (which you've provided with -cdrom). Googling suggests that you're getting this kernel from https://github.com/dhruvvyas90/qemu-rpi-kernel -- which has a readme file which tells you what command line options you need to use. Specifically:
 * you need to have 'root=/dev/sda2' in your -append argument
 * you want to use -hda rather than -cdrom

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]