All about PXE...
At MeetBSD California 2010 (#meetbsdca), one of the break out sessions "finishing" and merging the mini-tcp stack and HTTP loader support in pxeboot gain enough interest. The idea would be to get this eventually into base.
The code as-is, does work with an old version os 6(?)-stable. However BTX and the loader changed enough since then, that some updating will be needed to get this into 8-stable and -head.
From the README:
pxe_http library is user space implementation of simplified TCP/IP4 stack with support of sockets. Socket implementation is similar to common sockets, but differs, so I call this variant of sockets - "PXE sockets" features (read: simpliest ever implementation of): * supports TCP/UDP PXE sockets * DHCP client * DNS client * http based filesystem * ICMP echo