[PATCH v3 7/7] doc: board: apple: Add Apple M1 documentation

[Simon Glass]

Hi Mark,

On Thu, 14 Oct 2021 at 14:15, Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
>
> > From: Simon Glass <sjg at chromium.org>
> > Date: Mon, 11 Oct 2021 13:10:02 -0600
> >
> > Hi Mark,
> >
> > On Mon, 11 Oct 2021 at 10:40, Mark Kettenis <kettenis at openbsd.org> wrote:
> > >
> > > Provide preliminary instructions on how to get U-Boot to run on
> > > Apple Silicon Macs.
> >
> > Apple-Silicon
> >
> > This is ambiguous. The Macs are not made out of silicon. It is a Mac
> > using Apple Silicon.
>
> Well, this is the marketing term that tends to be used to distinguish
> them from the Macs with an Intel CPU in them.  It doesn't have to make
> sense ;).
>
> >
> > >
> > > Signed-off-by: Mark Kettenis <kettenis at openbsd.org>
> > > ---
> > >  doc/board/apple/index.rst |  9 +++++++
> > >  doc/board/apple/m1.rst    | 56 +++++++++++++++++++++++++++++++++++++++
> > >  doc/board/index.rst       |  1 +
> > >  3 files changed, 66 insertions(+)
> > >  create mode 100644 doc/board/apple/index.rst
> > >  create mode 100644 doc/board/apple/m1.rst
> > >
> > > diff --git a/doc/board/apple/index.rst b/doc/board/apple/index.rst
> > > new file mode 100644
> > > index 0000000000..8446847818
> > > --- /dev/null
> > > +++ b/doc/board/apple/index.rst
> > > @@ -0,0 +1,9 @@
> > > +.. SPDX-License-Identifier: GPL-2.0+
> > > +
> > > +Apple
> > > +=====
> > > +
> > > +.. toctree::
> > > +   :maxdepth: 2
> > > +
> > > +   m1
> > > diff --git a/doc/board/apple/m1.rst b/doc/board/apple/m1.rst
> > > new file mode 100644
> > > index 0000000000..2f2d940a4c
> > > --- /dev/null
> > > +++ b/doc/board/apple/m1.rst
> > > @@ -0,0 +1,56 @@
> > > +.. SPDX-License-Identifier: GPL-2.0+
> > > +
> > > +U-Boot for Apple Silicon Macs
> >
> > Apple-Silicon
> >
> > > +=============================
> > > +
> > > +Allows Apple Silicon Macs to boot U-Boot via the m1n1 bootloader
> >
> > Apple-Silicon
> >
> > > +developed by the Asahi Linux project.  At this point the machines with
> > > +the following SoCs work:
> > > +
> > > + - Apple M1 SoC
> > > +
> > > +On these SoCs the following hardware is supported:
> > > +
> > > + - S5L serial port
> > > + - Framebuffer
> > > + - USB 3.1 Type-C ports
> > > +
> > > +Device trees are currently provided for the M1 Mac mini (2020, J274)
> > > +and M1 MacBook Pro 13" (2020, J293).  The M1 MacBook Air (2020) is
> > > +expected to work with the J293 device tree.  The M1 iMac (2021) may
> >
> > Tested on MacBook Air 2020 A2337
> > Tested-by: Simon Glass <sjg at chromium.org>
> >
> > > +work with the J274 device tree.
> > > +
> > > +Building U-Boot
> > > +---------------
> > > +
> > > +.. code-block:: bash
> > > +
> > > +    $ export CROSS_COMPILE=aarch64-none-elf-
> > > +    $ make apple_m1_defconfig
> > > +    $ make
> > > +
> > > +This will build ``u-boot-nodtb.bin`` as well as devices trees for some
> > > +of the supported machines.  These device trees can be found in the
> > > +``arch/arm/dts`` subdirectory of your build.
> > > +
> > > +Image creation
> > > +--------------
> > > +
> > > +In order to run U-Boot on an Apple Silicon Mac, U-Boot has to be used
> > > +as a payload for the m1n1 bootloader.  Instructions for building m1n1
> > > +can be found here:
> > > +
> > > +    https://github.com/AsahiLinux/docs/wiki/SW%3Am1n1
> > > +
> > > +.. code-block:: bash
> > > +
> > > +    $ cat m1n1.macho t8103-j274.dtb u-boot-nodtb.bin > u-boot.macho
> >
> > or just u-boot.bin which is more normal
>
> But that one has the DTB baked in, so it makes no sense to use it in
> this context as the DTB is provided separately.

Yes, that's true. Please add a note explaining that.

Regards,
Simon