If I use runqemu to run a hddimg there's some warnings:

$ runqemu qemux86-64 /data/poky-master/tmp/deploy/images/intel-corei7-64/core-image-sato-base-intel-corei7-64.hddimg /data/poky-master/tmp/deploy/images/intel-corei7-64/bzImage-intel-corei7-64.bin nographic

readlink: missing operand
Try 'readlink --help' for more information.

[these happen as ROOTFS isn't set]

Running qemu-system-x86_64...
/data/poky-master/tmp/sysroots/x86_64-linux/usr/bin/qemu-system-x86_64 /data/poky-master/tmp/deploy/images/intel-corei7-64/core-image-sato-base-intel-corei7-64.hddimg -net nic,model=virtio -net tap,vlan=0,ifname=tap0,script=no,downscript=no -cpu core2duo -show-cursor -usb -usbdevice tablet -vga vmware -no-reboot -nographic -m 256 -serial mon:stdio -serial null
WARNING: Image format was not specified for '/data/poky-master/tmp/deploy/images/intel-corei7-64/core-image-sato-base-intel-corei7-64.hddimg' and probing guessed raw.
         Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted.
         Specify the 'raw' format explicitly to remove the restrictions.