[9fans] 9vx bootimage build instructions?

[EBo]

Doing some multipipe testing I'm running out of procs.  I was able to 
build a hacked boot image run under kvm, and now would like to do the 
same for 9vx.

Looking at sys/lib/dist/pc/plan9.ini, the images reference by both 
bootfile and nobootprompt do not exist.  Can someone give me the recipe 
for the special sauce to build/install a new boot image into 9vx?

  Thanks and best regards,

  EBo --