Writing to the UART offer an opportunity to receive and transmit out of the SoC, and therefore the simplest OS should be rather easy to write, simply by receiving and transmiting at the UART interface.
Below are the many examples of simple program written for some popular SoC: Singpolyma » Writing a Simple OS Kernel — Part 7, Serial Port Driver https://singpolyma.net/2013/02/writing-a-simple-os-kernel-part-7-serial-port-driver/ And a simple example to write to UART: http://wiki.osdev.org/ARM_RaspberryPi_Tutorial_C http://balau82.wordpress.com/2010/02/14/simplest-bare-metal-program-for-arm/ http://www.valvers.com/embedded-linux/raspberry-pi/step01-bare-metal-programming-in-cpt1 http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/ https://www.freebsd.org/doc/en/articles/serial-uart/ http://stackoverflow.com/questions/6870712/beagleboard-bare-metal-programming http://www.raspberry-projects.com/pi/programming-in-c/uart-serial-port/using-the-uart A complete program running on baremetal RPI writing Hello to UART is shown below: http://wiki.osdev.org/ARM_RaspberryPi_Tutorial_C And just in case u have got no money to buy any SoC board: http://balau82.wordpress.com/2010/02/28/hello-world-for-bare-metal-arm-using-qemu/ (which have a very good explanation of generating the binaries and laying it out in memories for the hardware simulator). -- You received this message because you are subscribed to the Google Groups "linuxkernelnewbies" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
