The boot fails for the same reason as in the mentioned question - just booting a kernel without anything else doesn't do much good. You must provide a disk. Or an initrd image. But just enabling initrd doesn't give you an initrd image magically. You need to prepare one and provide it to qemu like so:
qemu-system-i386 -kernel <your kernel> -initrd <your initrd image>
It's quite likely that you need to provide a disk as well.
There are a dozen or so ways to create and use disks for qemu, so here I explain just a very simple approach (see here for more).
First create a file, e.g.
qemu-img create -f raw mydisk.img 1G
which will create a 1 GiB-disk.
You can use this like so:
qemu <other options> -hda mydisk.img
If your initrd expects something (like a usable system) on your disk, you need to fill it first by mounting it to the local host, e.g.:
losetup /dev/loop0 mydisk.img
you can treat
/dev/loop0 like any other block device, i.e. you can run
fdisk on it etc. Once you have created partitions and filesystems you can mount them and put there what you need.
An alternative approach is to use an installation ISO image and attch that as a CD-ROM, e.g.
qemu <other options> -hda mydisk.img -hdb myiso.img -boot d
This will boot you into the system on the virtual CD-ROM, from there you can modify your disk as you like.