The GDT works but technically the length is incorrect. Fix this and add a
comment.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Add code to jump to a 64-bit Linux kernel. We need to set up a flat page
table structure, a new GDT and then go through a few hoops in the right
order.
Signed-off-by: Simon Glass <sjg@chromium.org>