Raspberry Pi 5

This appendix gives information about the Raspberry Pi 5 support in Circle.

Currently is only a subset of features supported on the Raspberry Pi 5. See the main project README for details!

The Cortex-A76 CPU of the Raspberry Pi 5 supports only AArch64 in the mode, which is used by Circle (EL1), so AArch32 is and will not be supported.

Installing

The resulting kernel image file has the name kernel_2712.img. Additionally the following files are required on the SD card:

  • bcm2712-rpi-5-b.dtb (can be downloaded in boot/)

  • config.txt (copy boot/config64.txt and rename it)

RP1 southbridge

The Raspberry Pi 5 features the RP1 southbridge, which provides many of the available peripherals. The RP1 peripherals are accessible automatically on entry into main() in Circle applications. No specific action is necessary for this purpose.

Display support

The firmware support for frame buffer device(s) is not as comfortable on the Raspberry Pi 5 as on earlier models. Because Circle relies on this firmware support, there are limitations, when using HDMI displays (e.g. no configuration in config.txt, cannot set display resolution from application) and DSI displays (e.g. the Official 7” touchscreen) do not work at all.

Fan support

If you want to use the Case Fan or Active Cooler with the Raspberry Pi 5 and the class CCPUThrottle, you have to add the option gpiofanpin=45 to the file cmdline.txt.

Serial devices

The serial bootloader is supported via the dedicated UART connector. Please note that the UART connector is the serial device ttyS11 (nDevice = 10), which is the default on the Raspberry Pi 5 for applications, which do not explicitly select a serial device number like all sample programs. This can be changed with the system option SERIAL_DEVICE_DEFAULT. The serial device at GPIO14/15 has the device number 0 (ttyS1).

Sound devices

The only option to generate sound is currently via USB streaming.