e0bd6f31ce
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>
58 lines
1.9 KiB
ReStructuredText
58 lines
1.9 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0+
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Arm Versatile Express
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=====================
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The vexpress_* board configuration supports the following platforms:
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* FVP_Base_RevC-2xAEMvA
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* FVP_BaseR_AEMv8R
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* Juno development board
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Fixed Virtual Platforms
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-----------------------
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The Fixed Virtual Platforms (FVP) are complete simulations of an Arm system,
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including processor, memory and peripherals. They are set out in a "programmer's
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view", which gives a comprehensive model on which to build and test software.
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The supported FVPs are available free of charge and can be downloaded from the
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Arm developer site [1]_ (user registration might be required).
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Supported features:
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* GICv3
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* Generic timer
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* PL011 UART
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* SMC91111 network interface
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The default configuration assumes that U-Boot is boostrapped from the start of
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the DRAM (address 0x80000000 for AEMvA; 0x00000000 for AEMv8R) using a suitable
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bootloader. Alternatively, U-Boot can be launched directly by mapping the binary
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to the same address (using the FVP's --data argument).
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The FVPs can be debugged using Arm Development Studio [2]_.
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FVP_BaseR
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^^^^^^^^^
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On Armv8r64 platforms (such as the FVP_BaseR), U-Boot runs at S-EL2, so
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CONFIG_ARMV8_SWITCH_TO_EL1 is defined so that the next stage boots at S-EL1. If
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S-EL2 is desired instead, the *armv8_switch_to_el1* environment variable is
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available. This can be set to *n* to override the config flag and boot the next
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stage at S-EL2 instead.
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Juno
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----
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The Juno development board is an open, vendor-neutral Armv8-A development
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platform that supports an out-of-the-box Linux software package. A range of
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plug-in expansion options enables hardware and software applications to be
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developed and debugged.
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References
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----------
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.. [1] https://developer.arm.com/tools-and-software/simulation-models/fixed-virtual-platforms
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.. [2] https://developer.arm.com/tools-and-software/embedded/arm-development-studio
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