Implementing HTTP support for libsa

by Zoltan for The NetBSD Foundation

libsa is the shared code for the bootloaders. currently, tftp is widely used to load the initial kernel if the block-device is not available yet (for example, for AoE/iSCSI). tftp uses udp by default, and the protocol itself does not define nor use any kind of authentication. having HTTP support would be a great ease for testing images. the project would involve writing/porting a minimalistic TCP stack.