[PATCH 0/5] Apple M1 Support

Sat Sep 25 18:45:54 CEST 2021

> From: Simon Glass <sjg at chromium.org>
> Date: Sat, 25 Sep 2021 08:42:30 -0600
> 
> Hi Mark,
> 
> On Sat, 25 Sept 2021 at 07:52, Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
> >
> > > From: Simon Glass <sjg at chromium.org>
> > > Date: Sat, 25 Sep 2021 07:27:41 -0600
> > >
> > > Hi Mark,
> > >
> > > On Sat, 25 Sept 2021 at 02:11, Mark Kettenis <mark.kettenis at xs4all.nl> wrote:
> > > >
> > > > > From: Simon Glass <sjg at chromium.org>
> > > > > Date: Fri, 24 Sep 2021 19:20:32 -0600
> > > > >
> > > > > Hi Mark,
> > > > >
> > > > > On Sat, 18 Sept 2021 at 07:54, Mark Kettenis <kettenis at openbsd.org> wrote:
> > > > > >
> > > > > > This series adds basic support for Apple's M1 SoC to U-Boot.
> > > > > > This builds a basic U-Boot that can be used as a payload
> > > > > > for the m1n1 boot loader being developed by the Asahi Linux
> > > > > > project.
> > > > > >
> > > > > > The goal here is to privide an UEFI interface on these machines that
> > > > >
> > > > > provide
> > > > >
> > > > > > allows booting various open source OSes.  This initial series provides
> > > > > > support for the serial port, framebuffer and the USB 3.1 Type-C ports.
> > > > > > It can boot a support OS (e.g. OpenBSD/arm64) from a USB disk.
> > > > > >
> > > > > > Mark Kettenis (5):
> > > > > >   arm: apple: Add initial support for Apple's M1 SoC
> > > > > >   serial: s5p: Add Apple M1 support
> > > > > >   misc: Add Apple DART driver
> > > > > >   arm: dts: apple: Add preliminary device trees
> > > > > >   doc: board: apple: Add Apple M1 documentation
> > > > > >
> > > > > >  arch/arm/Kconfig                              |  22 +
> > > > > >  arch/arm/Makefile                             |   1 +
> > > > > >  arch/arm/dts/t8103-j274.dts                   | 135 +++++
> > > > > >  arch/arm/dts/t8103-j293.dts                   |  97 ++++
> > > > > >  arch/arm/dts/t8103.dtsi                       | 506 ++++++++++++++++++
> > > > > >  arch/arm/include/asm/arch-m1/clk.h            |  11 +
> > > > > >  arch/arm/include/asm/arch-m1/uart.h           |  41 ++
> > > > > >  arch/arm/mach-apple/Kconfig                   |  18 +
> > > > > >  arch/arm/mach-apple/Makefile                  |   4 +
> > > > > >  arch/arm/mach-apple/board.c                   | 163 ++++++
> > > > > >  arch/arm/mach-apple/lowlevel_init.S           |  16 +
> > > > > >  configs/apple_m1_defconfig                    |  14 +
> > > > > >  doc/board/apple/index.rst                     |   9 +
> > > > > >  doc/board/apple/m1.rst                        |  54 ++
> > > > > >  doc/board/index.rst                           |   1 +
> > > > > >  drivers/misc/Kconfig                          |   7 +
> > > > > >  drivers/misc/Makefile                         |   1 +
> > > > > >  drivers/misc/apple_dart.c                     | 171 ++++++
> > > > > >  drivers/serial/Kconfig                        |   2 +-
> > > > > >  drivers/serial/serial_s5p.c                   |  22 +
> > > > > >  include/configs/apple.h                       |  38 ++
> > > > > >  .../interrupt-controller/apple-aic.h          |  15 +
> > > > > >  include/dt-bindings/pinctrl/apple.h           |  13 +
> > > > > >  include/dt-bindings/spmi/spmi.h               |  10 +
> > > > > >  24 files changed, 1370 insertions(+), 1 deletion(-)
> > > > > >  create mode 100644 arch/arm/dts/t8103-j274.dts
> > > > > >  create mode 100644 arch/arm/dts/t8103-j293.dts
> > > > > >  create mode 100644 arch/arm/dts/t8103.dtsi
> > > > > >  create mode 100644 arch/arm/include/asm/arch-m1/clk.h
> > > > > >  create mode 100644 arch/arm/include/asm/arch-m1/uart.h
> > > > > >  create mode 100644 arch/arm/mach-apple/Kconfig
> > > > > >  create mode 100644 arch/arm/mach-apple/Makefile
> > > > > >  create mode 100644 arch/arm/mach-apple/board.c
> > > > > >  create mode 100644 arch/arm/mach-apple/lowlevel_init.S
> > > > > >  create mode 100644 configs/apple_m1_defconfig
> > > > > >  create mode 100644 doc/board/apple/index.rst
> > > > > >  create mode 100644 doc/board/apple/m1.rst
> > > > > >  create mode 100644 drivers/misc/apple_dart.c
> > > > > >  create mode 100644 include/configs/apple.h
> > > > > >  create mode 100644 include/dt-bindings/interrupt-controller/apple-aic.h
> > > > > >  create mode 100644 include/dt-bindings/pinctrl/apple.h
> > > > > >  create mode 100644 include/dt-bindings/spmi/spmi.h
> > > > > >
> > > > > > --
> > > > > > 2.33.0
> > > > > >
> > > > >
> > > > > I gave this a whirl on a Macbook Air A2337 and needed the patch below
> > > > > to build the devicetree files. Sorry the formatting is broken.
> > > > >
> > > > > Also when booting I get this:
> > > > >
> > > > > ...
> > > > > Preparing to boot kernel at 0x808200000 with fdt at 0x8082e8000
> > > > > Valid payload found
> > > > > Preparing to run next stage at 0x808200000...
> > > > > MMU: shutting down...
> > > > > MMU: shutdown successful, clearing caches
> > > > >
> > > > >
> > > > > Then the display clears and it hangs. If I try the J274 devicetree it
> > > > > just reboots at that point.
> > > > >
> > > > > What should I expect? I was hoping for console output as I don't have
> > > > > serial connected. I don't have a suitable serial cable, and the USB
> > > > > gadget mode did not result in a ttyACM0 device appearing.
> > > >
> > > > For framebuffer support you also need the "30bpp framebuffer support"
> > > > series I posted earlier:
> > > >
> > > > https://patchwork.ozlabs.org/project/uboot/list/?series=262617
> > > >
> > > > With that your should get the usual U-Boot output on the screen.  I've
> > > > not tested the Air, but it should work there.
> > >
> > > Ah OK, yes that fixes it, thanks!
> > >
> > > So how do I get the keyboard to work in U-Boot? Or are you using
> > > serial somehow?
> >
> > The laptop keyboard doesn't work yet, so I'm using a USB keyboard when
> > I'm not using a serial console.  You need the xhci-dwc3 diff I sent
> > earlier for that:
> >
> > https://patchwork.ozlabs.org/project/uboot/patch/20210916140009.59009-1-kettenis@openbsd.org/
> 
> Actually that seems to be applied in mainline now. Yes USB keyboard works.
> 
> It looks like the keyboard needs SPI and there is some sort of linux
> keyboard driver, but perhaps not for M1.

Yes.  It is certaily doable in u-boot, but not a priority.  I plan to
revisit this once I have a driver going in OpenBSD and a better
understanding of how the hardware works.

> > > Also it takes for ever to put a test version on the device...how are
> > > you doing that for development?
> >
> > If you install m1n1.macho without a payload, you can then use the
> > python scripts that come with m1n1 to upload kernels over serial.
> > There is a USB gadget implementation in m1n1, so you don't need a real
> > serial connection.  Just connect a Linux machine to the M1 Mac using a
> > USB cable and a USB serial device should show up on the Linux machine
> > once m1n1 is running on the Mac.  Set the M1N1DEVICE environment
> > variable to the right device name and run:
> >
> > $ python3 linux.py --compression=none u-boot-nodtb.bin t8103-j274.dtb
> 
> OK I see. I did try the USB serial thing but was missing the fact that
> U-Boot seems to kill it. So this works fine, thank you will await your
> next series. Any way to get U-Boot serial console going in the same
> way?

Probably, but the existing USB gadget code in u-boot doesn't seem to
implement USB serial so it would be a significant amount of work.  And
it would only work after you bring the USB controller up, so it
wouldn't be very useful for debugging purposes.

There is a real serial port, and if you have another M1 Mac it should
be fairly easy to access it:

https://github.com/AsahiLinux/docs/wiki/Developer-Quickstart#using-an-m1-machine

Otherwise you need to build some special hardware.