[Qemu-devel] [PATCH] Allow -kernel without -hda

[Ed Swierk]

The qemu -kernel option currently requires specifying a hard disk
image with -hda. Ostensibly at least one hard disk is needed for
qemu's boot loader to populate the partition table in its array of
boot sectors.

Passing -hda /dev/zero tricks qemu into booting, which demonstrates
that the requirement is unnecessary. Booting with no disk image is
needed to support diskless configurations where a remote NFS directory
is used as the root filesystem. In this scenario, the user invokes
qemu with -kernel and -initrd options, with a specially configured
initrd that NFS-mounts a filesystem on / before passing control to the
real init.

The attached patch permits using the -kernel option with no disk
images, and skips copying the partition table in this case.

--Ed

qemu-kernel-without-hda.patch
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