allwinner: Add Allwinner A64 support

The Allwinner A64 SoC is quite popular on single board computers.
It comes with four Cortex-A53 cores in a singe cluster and the usual
peripherals for set-top box/tablet SoC.

The ATF platform target is called "sun50i_a64".

[Andre: adapted to amended directory layout, removed unneeded definitions ]

Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/docs/plat/allwinner.rst b/docs/plat/allwinner.rst
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+Trusted Firmware-A for Allwinner ARMv8 SoCs
+===========================================
+
+Trusted Firmware-A (TF-A) implements the EL3 firmware layer for Allwinner
+SoCs with ARMv8 cores. Only BL31 is used to provide proper EL3 setup and
+PSCI runtime services.
+U-Boot's SPL acts as a loader, loading both BL31 and BL33 (typically U-Boot).
+Loading is done from SD card, eMMC or SPI flash, also via an USB debug
+interface (FEL).
+BL31 lives in SRAM A2, which is documented to be accessible from secure
+world only.
+
+Current limitations:
+
+-  Missing PMIC support
+
+After building bl31.bin, the binary must be fed to the U-Boot build system
+to include it in the FIT image that the SPL loader will process.
+bl31.bin can be either copied (or sym-linked) into U-Boot's root directory,
+or the environment variable BL31 must contain the binary's path.
+See the respective `U-Boot documentation`_ for more details.
+
+To build:
+
+::
+
+    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=sun50i_a64 DEBUG=1 bl31
+
+.. _U-Boot documentation: http://git.denx.de/?p=u-boot.git;f=board/sunxi/README.sunxi64;hb=HEAD