This patch changes release VM image generation to use makefs(8) instead of using md(4), then newfs, and mounting and unmounting things many times. This provides a number of benefits:
- Simpler generation of images (the patch is net-negative): no need to attach md(4) devices and mount and unmount things
- Reduced privileges needed: if not for needing to have devfs mounted in the image at a few points, could do this in a zero-privilege jail
- Can generate cross-endian file systems: this enables generation of powerpc64 VM images (tested and working) on amd64 hosts
I have tested generation of amd64 and powerpc64 images and they work as before, with identical file system parameters and organization.