Open Source Summit Japan & Automotive Linux Summit 2021

Embedded systems are close collaboration of software and hardware. Initial hardware bring-up where Linux is able to boot is a challenging but interesting area of development. As more and more complex embedded devices are coming every day, it is important for embedded software programmer to understand the complete bring-up flow. Knowledge of reading and understanding of PCB schematics, know-how of various probe points on PCB, measuring some of the critical clocks and voltages of important power rails are very important for any board bring-up. Understanding of PCB schematic helps software programmer to correctly programs the GPIOs, PMIC configuration via I2C, configuration of correct debug port for debugging the software and help in programming any other external peripherals which are connected over any serial communication protocols. This talk will walk through all the steps involved in a typical hardware bring-up process, right from the external power is supplied till a distribution of embedded Linux is booted. Talk about the sanity testing of the board bring-up, tools which helps in debugging BootROM and subsequent bootloader stages, modification of device tree for booting Linux to creating a minimal root file system to get to the user space where an application gets his life.