I am trying to load a simple kernel using the qemu emulator but, qemu gets stuck at "Booting from hard disk".

The source code for the kernel can be found in the following link: https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-828-operating-system-engineering-fall-2012/ , in the lab 1 assignment in the directory obj/kern/kernel.img. Pdf of lab1, tar.gz of lab1, pointers1.c. The task was:
The first part concentrates on getting familiarized with x86 assembly language, the QEMU x86 emulator, and the PC's power-on bootstrap procedure. The second part examines the boot loader for our 6.828 kernel, which resides in the boot directory of the lab tree ...
% cd lab % make ... + mk obj/kern/kernel.img.. Now you're ready to run QEMU, supplying the file obj/kern/kernel.img, created above, as the contents of the emulated PC's "virtual hard disk." This hard disk image contains both our boot loader (obj/boot/boot) and our kernel (obj/kernel).
% make qemu