This patch changes the -tftp option to take a root directory instead of 
a prefix.  I know it's common for a TFTP server to take a prefix but 
it's easier typing wise to expose files as being part of a root.  For 
example, without this patch, to PXE boot:

qemu -hda disk.img -tftp /home/anthony/tftpboot -bootp 
/home/anthony/tftpboot/pxelinux.0

With the patch:

qemu -hda disk.img -tftp /home/anthony/tftpboot -bootp /pxelinux.0

Also helps deal with the fact that TFTP filenames are limited to 512 
characters.

Regards,

Anthony Liguori