Apple Macbook Air M1 (apple-tonga)

== Contributors ==
# Asahi Linux Project
== Users owning this device ==
== How to enter flash mode ==
for DFU mode: https://support.apple.com/en-gb/guide/apple-configurator-2/apdd5f3c75ad/mac
== Bootloader ==
According to Asahi Linux's Wiki, m1n1 is the bootloader for Linux kernel booting.
m1n1 is the bootloader developed by the Asahi Linux project to bridge the Apple (XNU) boot ecosystem to the Linux boot ecosystem.
= What it does(from their wiki) =
*Initializes hardware
*Puts up a pretty logo
*Loads embedded (appended) payloads, which can be:
*Device Trees (FDTs), with automatic selection based on the platform
*Initramfs images (compressed CPIO archives)
*Kernel images in Linux ARM64 boot format (optionally compressed)
*Configuration statements
*Chainloads another version of itself from a FAT32 partition (if configured to do so)
Proxy mode enables a huge toolset of developer features, from reducing your Linux kernel test cycle to 7 seconds, to live hardware probing and experimentation, to a hypervisor capable of running macOS or Linux and tracing hardware accesses in real time while providing a virtual UART over USB. 
m1n1 can load U-Boot as a payload.
=== U-Boot ===
U-Boot is the default payload for m1n1 stage 2, and is used to provide a standard preboot environment familiar to AArch64 developers. External boot is not supported with the native Apple Silicon boot tooling, making U-Boot a hard necessity for providing a PC-like boot environment.
It is able to boot from any external media (USB drive, network, etc.) and users an execute any EFI binaries.
==== U-Boot Status ====
Feature 	Status
USB-A Ports	Not working due to their controller requiring firmware which we cannot redistribute.
USB devices	Certain USB devices which expose multiple functions (hubs with NICs, fancy gaming keyboards, etc.) do not work.
USB Hubs 	Hubs with SD Card slots may cause U-Boot crash.
== Installation ==
This device now have a WIP port in postmarketOS,like any other Linux port for Apple M1, you'll need to set up a simple UEFI environment to continue installation. Asahi Linux website and their script can help you to do this. 
Use pmbootstrap to generate a postmarketOS image, then follow this guide to deploy it to an USB stick. 
After you finished deploying postmarketOS on your USB stick, you need to do some extra work to boot your system: 
# Download rEFInd and install it to your MacBook's EFI partition( just copy refind_aa64.efi to the root of the EFI partition, rename it to BOOTAA64.efi );
# Power off your Mac when you finished setting up UEFI environment, then plug in your USB drive and turn on your Mac again;
# When you see rEFInd boot menu, select "boot vmlinux-asahi from 486 MiB Volume" and hit enter.
== UART Debug Port ==
This device has UART port on the USB-C port closest to the edge. To activate this, you need to send various of commands via USB-PD.
If you enabled UART successfully, here is a command reference :
=== 103: PD reset ===
This needs a 0x8000 argument (taken from the get action info reply).
=== 105: Reboot ===
This needs a 0x8000 argument (taken from the get action info reply).
==== about reboot command ====
the command "5AC8012,0105,80000000" is sent through the Serial Monitor of Arduino IDE. if you want to reboot Mac more conveniently.
=== 106: DFU / hold mode ===
This needs a 0x8001 argument (taken from the get action info reply). It only works properly in DFP mode (Mac acting as UFP).
This mode is special. On the Mac Mini, a hard shutdown normally disables PD communications and UFP mode (Rd open). However, a hard shutdown from this mode (e.g. holding down the power button) will power down the machine while PD communications remain active. The machine can also be rebooted via 105 into normal mode, and again PD is not reset and existing modes remain active. This can be used to maintain debug connectivity through a machine reset.
=== 306: Debug UART ===
Pin order: TX, RX
This can be mapped to pin sets 0-2 (D+/D- B, D+/D- A, or SBU1/2). The UART uses 1.2V voltage levels.
pin 1 is TX and pin 2 is RX, orientation-aware (for CC=CC2 they are flipped). In other words, the SBU pin on the same side of the connector (A or B) as your CC pin is TX.
=== 606: DFU USB ===
Pin order: D+, D- (of course)
This is automatically mapped to pin set 1 (D+/D- primary) in DFU mode, but can be moved.
=== 4606: Debug USB(What we need) ===
Interesting. This is not main-CPU-driven, it enumerates even when the system is off (in persistent mode). It re-enumerates on power transitions.
=== 0803: An I²C bus (3.3V) ===
Pin order: SCL, SDA
Device addresses seen (unshifted): 0x38, 0x3f
It doesn't do anything interesting during normal boot, but does in macOS.
Also, sometimes it just sends START 00 STOP (no ACK cycle) at slower speed (?)
=== 0809: Another I²C bus (3.3V) ===
Pin order: SCL, SDA
Device addresses seen (unshifted): 0x6b, 0x38, 0x3f,
=== TBD ===
0206 weak (30kΩ) pull to 1.2V, no reaction to gnd, no transitions. Good chance this is SWD.
0301 1.2V, one pin drives high, the other no drive. Another UART? high-z in DFU mode, no activity except high pin tracking power/boots.
0303 Only maps to pinsets 1-2? Seems to be GND? No transitions seen. Unused UART mode?
== See also ==
This device does currently boot and works to a degree, it has a actively developed Linux port (https://asahilinux.org/).
Initial merge request: MR5913 
== Notes ==
Now you can install other Linux like Debian from this website:[Other].
To use Asahi's graphics driver, Update your kernel to their develop branch.