ARM-software/arm-trusted-firmware — pull request #139 by athoelke (2014-06-17 11:55:38+00:00)
Title: Initialize CPU contexts from entry_point_info

Consolidate all BL3-1 CPU context initialization for cold boot, PSCI
and SPDs into two functions:
* The first uses entry_point_info to initialize the relevant
cpu_context for first entry into a lower exception level on a CPU
* The second populates the EL1 and EL2 system registers as needed
from the cpu_context to ensure correct entry into the lower EL

This patch alters the way that BL3-1 determines which exception level
is used when first entering EL1 or EL2 durign cold boot - this is now
fully determined by the SPSR value in the entry_point_info for BL3-3,
as set up by the platform code in BL2 (or otherwise provided to BL3-1).

In the situation that EL1 (or svc mode) is selected for a processor
that supports EL2, the context management code will now configure all
essential EL2 register state to ensure correct execution of EL1. This
allows the platform code to run non-secure EL1 payloads directly
without requiring a small EL2 stub or OS loader.