1 year ago.
How to load and excecute a Cortex M4 from SWD without a loader?
How to load and excecute a Cortex M4 from SWD without a loader? I have a unique need to load a firmware image into SRAM via SWD interface, the boot it up from SWD interface without using a regular Firmware loader. What is the correct sequence to boot the Firmware image from SRAM? I am working with Cortex M4.
1 year ago.
You will have to do some research on the specific Cortex-M4 device that you are using as each silicon manufacturer will offer different boot options. We're not familiar with any vendor that allows one to boot over SWD. SWD is used for debugging and in application/mission mode the SWD pins after booting are usually multiplexed to have other functionality. Vendors will most certainly have an option to boot from SRAM but naturally you will need to get that memory programmed before you start executing from there!
For example - if you consult a STM32 reference manual you'll find several pins (BOOT0, BOOT1 and potentially others) that set the boot mode. ST also have a detailed application note which describes how to use their internal bootloader to program flash through their supported peripherals. We think a document like this is what you are after:
Please check with your device manufacturer's website for similar literature. The device manufacturer will be best suited to answer any questions you have about the boot process and device programming.
-Ralph, Team Mbed