How to use qemu to boot up Android in an ARM host?

I know that I can use the Android emulator, but that requires me to download the entire Android source code and compile it. I tried following how Android boots normally, but the best I got was an infinite bootloop — it seems that I haven’t correctly specified the root partition in -append, but I have no idea where that would be.
I’ve been using the images from here.

Here’s my qemu configuration so far —

sudo qemu-system-aarch64 
-M virt,accel=hvf,highmem=off -m 7G 
-cpu cortex-a57 
-kernel arm64-v8a/kernel-ranchu 
-initrd arm64-v8a/ramdisk.img 
-append "rw console=ttyAMA0,38400 keep_bootcon" 
-smp 4 
-device virtio-gpu-pci,xres=2880,yres=1650 
-drive file=arm64-v8a/system.img,format=raw,index=0,media=disk