m33 firmware at

This firmware has three purposes:

• bridge m33 hardware with linux
• minimize power consumption during suspend
• allow user code to run

Design overview

Power management

Power management is done in main.c as well as lpm.c

Hardware bridge

Hardware bridge to linux is split by component:

• app_srtm.c: main linux communication driver
• srtm/services/*: individual protocols for each driver
• app_*.c: hardware implementation for each driver

User defined code

The custom directory contains hooks that can be customized for specific applications.

• custom/custom.c: hooks at various points of lifecycle (boot, before/after suspend) and gpio irq
• custom/cli_custom.c: add commands for CLI (ttyrpmsg0 from linux or console)
• custom/app_tty_custom.c: free form console that can be bound as ttyrpmsgX through linux DTS

Acknowledgement

This was originally based on NXP's power_mode_switch demo as found in https://github.com/nxp-mcuxpresso/mcux-sdk-examples evkmimx8ulp/demo_apps/power_mode_switch directory.