Replace bootwrapped kernel instructions from User Guide
Replace bootwrapped kernel instructions from User Guide

The instructions to boot the bootwrapped kernel were outdated.

Also, the bootwrapped kernel boot flow isn't really useful. It was meant
to be a replacement for the Trusted Firmware-A, not to be used as the next
step during boot.

The instructions have been removed in favour of the new build option
ARM_LINUX_KERNEL_AS_BL33. This new system directly boots the Linux
kernel from BL31, and requires RESET_TO_BL31 to be 1. Also, the kernel
has to be preloaded in memory, so PRELOADED_BL33_BASE has to be set to its
address. This way, the runtime services of the Trusted Firmware-A are
available for the kernel in the least possible amount of time.

This new system requires the DTB to be patched so that the kernel knows
where the ramdisk is. A short script to add this information to the DTB
has been added to the User Guide. The information related to it can be
found in the following file in the Linux kernel tree:
``Documentation/devicetree/bindings/chosen.txt``

Change-Id: Ide135580959e09f6aa8e4425f37ea55d97439178
Signed-off-by: Antonio Nino Diaz <5c24ff39be768bf31f4deee44042a11772cfd02a@arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware