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authorPeter Hoyes <Peter.Hoyes@arm.com>2021-08-19 16:53:14 +0100
committerTom Rini <trini@konsulko.com>2021-09-02 11:19:57 -0400
commite0bd6f31ce41771964b64dc86dcd976c8bdb116a (patch)
tree7e23bf801e9d1201a94a588413fe8f3fe5a37591 /doc
parent30e5a449e8c7739965757879bb17efbd3a8f0ee2 (diff)
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doc: Add documentation for the Arm vexpress board configs
Create a new documentation section for Arm Ltd boards with a sub-page for the vexpress board (FVP-A, FVP-R and Juno). Document how the armv8_switch_to_el1 environment variable can be used to switch between booting from S-EL2/S-EL1 at runtime on the BASER_FVP. Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Diffstat (limited to 'doc')
-rw-r--r--doc/arch/arm64.rst3
-rw-r--r--doc/board/armltd/index.rst9
-rw-r--r--doc/board/armltd/vexpress64.rst57
-rw-r--r--doc/board/index.rst1
4 files changed, 69 insertions, 1 deletions
diff --git a/doc/arch/arm64.rst b/doc/arch/arm64.rst
index 80498f6..f20eb8f 100644
--- a/doc/arch/arm64.rst
+++ b/doc/arch/arm64.rst
@@ -18,7 +18,8 @@ Notes
classical firmware (like initial hardware setup, CPU errata workarounds
or SMP bringup). U-Boot can be entered in EL2 when its main purpose is
that of a boot loader. It can drop to lower exception levels before
- entering the OS.
+ entering the OS. For ARMv8-R it is recommened to enter at S-EL2, as for this
+ architecture there is no S-EL3.
2. U-Boot for arm64 is compiled with AArch64-gcc. AArch64-gcc
use rela relocation format, a tool(tools/relocate-rela) by Scott Wood
diff --git a/doc/board/armltd/index.rst b/doc/board/armltd/index.rst
new file mode 100644
index 0000000..b6786c1
--- /dev/null
+++ b/doc/board/armltd/index.rst
@@ -0,0 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Arm Ltd
+=============
+
+.. toctree::
+ :maxdepth: 2
+
+ vexpress64.rst
diff --git a/doc/board/armltd/vexpress64.rst b/doc/board/armltd/vexpress64.rst
new file mode 100644
index 0000000..37ef564
--- /dev/null
+++ b/doc/board/armltd/vexpress64.rst
@@ -0,0 +1,57 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Arm Versatile Express
+=====================
+
+The vexpress_* board configuration supports the following platforms:
+
+ * FVP_Base_RevC-2xAEMvA
+ * FVP_BaseR_AEMv8R
+ * Juno development board
+
+Fixed Virtual Platforms
+-----------------------
+
+The Fixed Virtual Platforms (FVP) are complete simulations of an Arm system,
+including processor, memory and peripherals. They are set out in a "programmer's
+view", which gives a comprehensive model on which to build and test software.
+
+The supported FVPs are available free of charge and can be downloaded from the
+Arm developer site [1]_ (user registration might be required).
+
+Supported features:
+
+ * GICv3
+ * Generic timer
+ * PL011 UART
+ * SMC91111 network interface
+
+The default configuration assumes that U-Boot is boostrapped from the start of
+the DRAM (address 0x80000000 for AEMvA; 0x00000000 for AEMv8R) using a suitable
+bootloader. Alternatively, U-Boot can be launched directly by mapping the binary
+to the same address (using the FVP's --data argument).
+
+The FVPs can be debugged using Arm Development Studio [2]_.
+
+FVP_BaseR
+^^^^^^^^^
+
+On Armv8r64 platforms (such as the FVP_BaseR), U-Boot runs at S-EL2, so
+CONFIG_ARMV8_SWITCH_TO_EL1 is defined so that the next stage boots at S-EL1. If
+S-EL2 is desired instead, the *armv8_switch_to_el1* environment variable is
+available. This can be set to *n* to override the config flag and boot the next
+stage at S-EL2 instead.
+
+Juno
+----
+
+The Juno development board is an open, vendor-neutral Armv8-A development
+platform that supports an out-of-the-box Linux software package. A range of
+plug-in expansion options enables hardware and software applications to be
+developed and debugged.
+
+References
+----------
+
+.. [1] https://developer.arm.com/tools-and-software/simulation-models/fixed-virtual-platforms
+.. [2] https://developer.arm.com/tools-and-software/embedded/arm-development-studio
diff --git a/doc/board/index.rst b/doc/board/index.rst
index 8588e45..827f086 100644
--- a/doc/board/index.rst
+++ b/doc/board/index.rst
@@ -10,6 +10,7 @@ Board-specific doc
advantech/index
AndesTech/index
amlogic/index
+ armltd/index
atmel/index
congatec/index
coreboot/index