An update from the Corellium folks working on Linux on the Apple M1, looks like they already got everything working:
Asahi Linux Progress Report: January/February 2021
21–30 of 69 posts
Re: Asahi Linux Progress Report: January/February 2021
#22Earlier quoted context omitted.
It's not really a question of firmware support; the standards need amending to support all of this, and then OSes need to implement core support. Basically, there will never be a way to run Windows natively on Apple Silicon without someone pushing to have a pile of new Apple-specific stuff added to ACPI, and then getting Microsoft to implement support for it. The only way to run Windows on Apple Silicon without all o…
Doesn't the MacOS kernel use some bastardized version of device tree? I'm not sure of their commitment to UEFI/ACPI..
It pre-dates Device Tree support on Linux for Arm. Both have a common ancestor (OpenFirmware, notably used for PowerPC Macs)
Re: Asahi Linux Progress Report: January/February 2021
#23I wonder if it is possible for any Linux laptop with USB-C to deliver USB-PD commands to M1 USB-C devices in order to get the serial stuff working?
Re: Asahi Linux Progress Report: January/February 2021
#24An update from the Corellium folks working on Linux on the Apple M1, looks like they already got everything working: https://twitter.com/cmwdotme/status/1355660127433535490
Everything except the GPU (and display controller)... which is a bigger challenge than every other driver combined :) (their kernel runs only on the boot-time framebuffer so far)
Unfortunately, we've yet to hear any feedback from Corellium (they've been CCed on my upstream submissions), nor have they interacted with the Linux kernel community in any other way, so I have no idea what their plans are.
So far, after working with upstream on solving the core problems I mentioned in this article, the M1 support series we are submitting supersedes Corellium's patches for FIQ, the nGnRnE issue, SMP, AIC, UART; we settled on different solutions for all of those from how Corellium did it. I²C is also another one that will be superseded most likely (Corellium wrote their own driver instead of improving the PASemi one; it doesn't seem like there are any show-stoppers that would warrant that approach). I don't know what they're going to do moving forward; perhaps they will re-base on top of mainline and drop their conflicting patches, or perhaps they will attempt to maintain their kernel as a Linux fork...
Re: Asahi Linux Progress Report: January/February 2021
#25How did they figure all of this out from a non-documented platform, especially the specifics of Stage 1 (LLB)? [1] It blows my mind. [1] https://github.com/AsahiLinux/docs/wiki/SW:Boot
That's mostly just imported from existing iPhone research, where people have been reverse engineering iBoot (from exploitable phones, since it's encrypted) for a long time now. Combining that with what is known about how the M1 works from observation / the boot config data structures yields a decent picture, without actually seeing the code.
Here's a fun one though: how I found and documented the Apple-proprietary memory compression/uncompression instructions.
https://twitter.com/marcan42/status/1362450439845781505
A lot of the hardware research ends up looking like this; twiddle random bits and see what happens. For more complex drivers (e.g. the GPU), my plan is to run macOS under a thin hypervisor built on m1n1 that can log hardware accesses.
Re: Asahi Linux Progress Report: January/February 2021
#26An update from the Corellium folks working on Linux on the Apple M1, looks like they already got everything working: https://twitter.com/cmwdotme/status/1355660127433535490
Everything except the GPU (and display controller)... which is a bigger challenge than every other driver combined :) (their kernel runs only on the boot-time framebuffer so far) Unfortunately, we've yet to hear any feedback from Corellium (they've been CCed on my upstream submissions), nor have they interacted with the Linux kernel community in any other way, so I have no idea what their plans are. So far, after wor…
Hmm, I see them participating on linux-arm-kernel list, nothing since January though:
Re: Asahi Linux Progress Report: January/February 2021
#27I wonder if it is possible for any Linux laptop with USB-C to deliver USB-PD commands to M1 USB-C devices in order to get the serial stuff working?
It depends on whether the PD controller chip supports sending SOP'DEBUG/SOP"DEBUG packets, and, for those that do, whether it is exposed to the host OS or the firmware running on it does so.
However, even once you have that working, you still need to connect the other pins to a serial port adapter, and I don't know if any other laptops implement this in a compatible way, so you would probably still need some kind of cut-up cable that breaks out the serial wires.
Re: Asahi Linux Progress Report: January/February 2021
#28I wonder if it is possible for any Linux laptop with USB-C to deliver USB-PD commands to M1 USB-C devices in order to get the serial stuff working?
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Re: Asahi Linux Progress Report: January/February 2021
#29I wonder if it is possible for any Linux laptop with USB-C to deliver USB-PD commands to M1 USB-C devices in order to get the serial stuff working?
It depends on whether the PD controller chip supports sending SOP'DEBUG/SOP"DEBUG packets, and, for those that do, whether it is exposed to the host OS or the firmware running on it does so. However, even once you have that working, you still need to connect the other pins to a serial port adapter, and I don't know if any other laptops implement this in a compatible way, so you would probably still need some kind of…
So what is different about an M1 that lets you do this without the serial port adaptor?
Re: Asahi Linux Progress Report: January/February 2021
#30Earlier quoted context omitted.
It depends on whether the PD controller chip supports sending SOP'DEBUG/SOP"DEBUG packets, and, for those that do, whether it is exposed to the host OS or the firmware running on it does so. However, even once you have that working, you still need to connect the other pins to a serial port adapter, and I don't know if any other laptops implement this in a compatible way, so you would probably still need some kind of…
So what is different about an M1 that lets you do this without the serial port adaptor?
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