Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Print kernel args as late as possible before jumping into kernel.

Print kernel args when booting the kernel.

Determine kernel load address dynamically from u-boot memory map.

The generic ELF loading code maps the kernel into low memory
by subtracting KERN_BASE. So the copyin/copyout/readin functions
are always called with low addresses. This code finds the largest
DRAM block from the U-Boot memory map and adds that base to
the addresses.

In particular, this fixes ubldr on AM3358, which has DRAM
mapped to 0x80000000 at power-on.

Move U-Boot compatibility library to WARNS=2 level.

style(9) & style.Makefile(9)

Reviewed by: raj

MFp4 (e500):

Add support for U-Boot. This uses the U-Boot API as developed by
Rafal and which is (will be) part of U-Boot 1.3.2 and later.

Credits to: raj@