From d22a765755ba318ce162a976f51d44000a201394 Mon Sep 17 00:00:00 2001
From: Stephen Warren <swarren@wwwdotorg.org>
Date: Fri, 1 Apr 2016 21:14:15 -0600
Subject: ARM: add Raspberry Pi 3 64-bit config
On all Pis so far, the VC FW provides a short stub to set up the ARM CPU
before entering the kernel (a/k/a U-Boot for us). This feature is not
currently supported by the VC FW when booting in 64-bit mode. However,
this feature will likely appear in the near future, and this U-Boot port
assumes that such a feature is in place. Without that feature, or a
temporary workaround described below, U-Boot will not boot.
Once the VC FW does provide the ARM stub, u-boot.bin built for rpi_3 can
be used drectly as kernel7.img, in the same way as any other RPi port. The
following config.txt is required:
# Fix mini UART input frequency, and setup/enable up the UART.
# Without this option, U-Boot will not boot, even if you don't care
# about the serial console. This option will always be required for
# all RPi3 use-cases, unless the PL011 UART is used, which is not
# yet supported by rpi_3* builds of U-Boot.
enable_uart=1
# Boot in AArch64 (64-bit) mode.
# It is possible that a future VC FW will remove the need for this
# option, instead auto-setting 32-/64-bit mode based on the "kernel"
# filename present on the SD card.
arm_control=0x200
Prior to the VC FW providing the ARM boot stub, you can use the following
steps to build an equivalent stub into the U-Boot binary:
git clone https://github.com/swarren/rpi-3-aarch64-demo.git \
../rpi-3-aarch64-demo
(cd ../rpi-3-aarch64-demo && ./build.sh)
Build U-Boot for rpi_3 in the usual way
cat ../rpi-3-aarch64-demo/armstub64.bin u-boot.bin > u-boot.bin.stubbed
Use u-boot.bin.stubbed as kernel7.img on the Pi SD card.
In this case, the following additional entries are required in config.txt:
# Tell the FW to load the kernel image at address 0, the reset vector.
kernel_old=1
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
---
include/configs/rpi_3.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
create mode 100644 include/configs/rpi_3.h
(limited to 'include/configs/rpi_3.h')
diff --git a/include/configs/rpi_3.h b/include/configs/rpi_3.h
new file mode 100644
index 0000000000..0dd9e7e40a
--- /dev/null
+++ b/include/configs/rpi_3.h
@@ -0,0 +1,14 @@
+/*
+ * (C) Copyright 2012-2016 Stephen Warren <swarren@wwwdotorg.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __CONFIG_H
+#define __CONFIG_H
+
+#define CONFIG_SYS_CACHELINE_SIZE 64
+
+#include "rpi-common.h"
+
+#endif
--
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