Allwinner A64
The Allwinner A64 is also known as the Sunxi i50
Key Features
The A64 runs quad Arm Cortex A53 cores at a little over 1GHz, and a Mali GPU.
Interfaces;
- UART
- Ethernet
- I²C
- I²S
- SDIO
- USB host & OTG
- Video in & out
The A64 is usually paired with the AXP803 PMIC to handle power management. The CPU talks to it over an I²C-like bus called RSB used only for this purpose.
The best known devices that use the A64 are the Pine64 A64-LTS and the PinePhone. It is also used in a variety of devices and dev boards from other manufacturers.
Docs
Allwinner stuff is general well documented at linux-sunxi.org
Allwinner A64 User Manual v1.1
9front
The most up-to-date eperimental kernel for 9front on the A64 is by driusan, which is currently being built for the PinePhone. It is possible to cut out the phone only stuff and boot it on the A64-LTS board.
If you are trying to run 9front on the Pine64 A64-LTS, the u-boot used by FreeBSD includes the drivers for the ethernet, so it can be used to load kernels and plan9.ini via tftp, rather than loading it from SD card or thumb drive. From u-boot, load plan9.ini to 0x40010000 and the kernel to 0x40100000, then 'go 0x40100000'.
9front currently supports;
- UART
- RSB with PMIC
- I²C
- Ethernet (buggy, interrupt issue)
- SDIO
- KeyADC (the volume buttons)
- RTC
-
CPU tempurature
-
Quectel EG25
The PinePhone has a 4G cell radio. The cell radio is a self contained thing that boots and runs its own firmware. With the UART, is is possible to send it AT commands and send SMS messages.
- Screen
The blacklight, Video out, and touch screen sensor are a work in progress.
- devarch
Files to read CPU temerature, the PLL gate and reset states, and to read and change the CPU clock speed, and the PMIC, are availble in the #P kernel device.