Comment 11 for bug 524893

A qemu bug seems possible, but unlikely. I have other kernels and initrd gzipped cpio archivies that are very similar and run fine with qemu versatile. The only difference here is the cpu is cortex-a8 but this doesn't seem related to initrd processing.

I also took the initrd.gz and extracted it with gunzip and cpio and took the filesystem data and put the same data into an ext4 filesystem as described by https://wiki.ubuntu.com/ARM/RootfsFromScratch/QemuDebootstrap
then I could boot the kernel and filesystem just fine using:

qemu-system-arm -M versatilepb -cpu cortex-a8 -m 256 -kernel vmlinuz -hda rootfs.img -nographic -append "rootwait root=/dev/sda console=ttyAMA0,115200 init=/bin/sh rw"

Since this boots fine there is nothing wrong with the filsystem information itself.

qemu loader and ramdisk size don't seem related. The initrd is loaded by qemu after the kernel at 0x800000 so if there is any corruption the initrd file would overwrite the kernel, not the other way around.
The kernel size is only 0x2ca574

I think the next step is to look at the kernel configuration, I couldn't extract it using extract-ikconfig

What's the best way to get the kernel configuration?