Ideas for calling bootloader from application code?

sima · ‎2009-03-09

Posted on March 10, 2009 at 05:39

sima · ‎2011-05-17

Posted on May 17, 2011 at 13:05

Hello all, a boot loader question again :-]

I want to be able to activate the boot loader from my application code. I have an idea how to do that.

At reset, the boot loader is called. If the boot loader doesnâ€™t receive any boot loader specific command within X second it calls the application code through itâ€™s reset vector.

When the application code receives a boot loader specific command it must call the boot loader though the boot loaders reset vector.

But before the call I save information in SRAM at a specific location to indicate to the boot loader what command was received so the boot loader can continue from that point.

What do you think of the idea?

trevor1 · ‎2011-05-17

Posted on May 17, 2011 at 13:05

Hi

You could just save the data in backup registers and then reset to run your bootloader. The bootloader will then be able to read the backup registers. This is what I do.

The backup registers are not cleared by a reset.

Regards

Trevor

sima · ‎2011-05-17

Posted on May 17, 2011 at 13:05

But I thought using SRAM was easier and faster.

I dont't think SRAM gets erased if I jump to the bootloaders Reset_Handler()?

Or does it get erased by the start up code before main()?

trevor1 · ‎2011-05-17

Posted on May 17, 2011 at 13:05

I'm not sure, I guess it depends on your pre main start-up code -- which will depend on what tools you are using. It should be easy to try.