Re: [PATCH 1/2] doc: Add documentation for the Arm VExpress64 board configs

[Andre Przywara <andre.przywara@arm.com>]

On Fri, 17 Dec 2021 09:37:12 -0700
Simon Glass <sjg@chromium.org> wrote:

Hi,

> On Tue, 14 Dec 2021 at 10:55, Andre Przywara <andre.przywara@arm.com> wrote:
> >
> > From: Peter Hoyes <Peter.Hoyes@arm.com>
> >
> > Create a new documentation section for Arm Ltd boards with a sub-page
> > for the FVP VExpress64 system.
> >
> > Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
> > [Andre: remove Juno stub]
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> >  doc/board/armltd/fvp64.rst | 30 ++++++++++++++++++++++++++++++
> >  doc/board/armltd/index.rst | 10 ++++++++++
> >  doc/board/index.rst        |  1 +
> >  3 files changed, 41 insertions(+)
> >  create mode 100644 doc/board/armltd/fvp64.rst
> >  create mode 100644 doc/board/armltd/index.rst
> >
> > diff --git a/doc/board/armltd/fvp64.rst b/doc/board/armltd/fvp64.rst
> > new file mode 100644
> > index 0000000000..9817b0aa3f
> > --- /dev/null
> > +++ b/doc/board/armltd/fvp64.rst
> > @@ -0,0 +1,30 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +
> > +Fixed Virtual Platforms
> > +=======================
> > +
> > +The Fixed Virtual Platforms (FVP) are complete software 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
> > +
> > +The default configuration assumes that U-Boot is bootstrapped using a suitable
> > +bootloader, such as Trusted Firmware-A [4]_. The u-boot binary can be passed  
> 
> TF-A has become a bootloader?!

As much as U-Boot is firmware, yes :-P

The full featured TF-A suite contains a whole loading stage (BL2), some
platforms have MMC and even USB drivers. We can also put a Linux kernel
directly into DRAM, then TF-A directly drops into Linux directly.

The point is that for those virtual platforms a boot*loader* is strictly
speaking not required, since you can much easier load through your host
- either via semihosting or by letting the model programme put your
binaries directly into the emulated DRAM.

> 
> > +into the TF-A build: ``make PLAT=<platform> all fip BL33=u-boot.bin``  
> 
> What is <platform> in this case?

That depends on the exact model, but just "fvp" would probably be good
enough to put in here.

Cheers,
Andre

> > +
> > +The FVPs can be debugged using Arm Development Studio [2]_.
> > +
> > +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/armltd/index.rst b/doc/board/armltd/index.rst
> > new file mode 100644
> > index 0000000000..caa6fd2bb0
> > --- /dev/null
> > +++ b/doc/board/armltd/index.rst
> > @@ -0,0 +1,10 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +.. Copyright (C) 2021 Arm Ltd.
> > +
> > +ARM Ltd. boards and emulated systems
> > +====================================
> > +
> > +.. toctree::
> > +   :maxdepth: 2
> > +
> > +   fvp64
> > diff --git a/doc/board/index.rst b/doc/board/index.rst
> > index 74ea33e081..78b486538b 100644
> > --- a/doc/board/index.rst
> > +++ b/doc/board/index.rst
> > @@ -11,6 +11,7 @@ Board-specific doc
> >     AndesTech/index
> >     amlogic/index
> >     apple/index
> > +   armltd/index
> >     atmel/index
> >     congatec/index
> >     coreboot/index
> > --
> > 2.25.1
> >  
> 
> Regards,
> Simon