How is Bootloader copied to RAM

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 12:34:46 GMT

Happy to help :)

RE: How is Bootloader copied to RAM

Aadishri GS — Thu, 25 Apr 2019 12:31:58 GMT

Viewing a .map file made this entire discussion more clear. Thanks again for the external read link!

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 11:40:06 GMT

Yes, program code is executed from flash. Give this a read. Hopefully it'll help you understand this stuff better.

RE: How is Bootloader copied to RAM

Aadishri GS — Thu, 25 Apr 2019 11:37:14 GMT

That was clear!

One last question... Is it the same for Application as well? No code is placed in RAM? Only non-persistent data? Does this mean all code executed from Flash? I am little confused about this part

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 11:33:33 GMT

To store any non-persistent data, e.g. variables, buffers, etc.

RE: How is Bootloader copied to RAM

Aadishri GS — Thu, 25 Apr 2019 11:31:19 GMT

Sorry for my chain of questions and thanks for your patience with this beginner.

Typically what can the Bootloader use that RAM region for? Any examples will be extremely helpful

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 11:26:55 GMT

That's just the RAM region that the bootloader has access to. If you're not using a SoftDevice you should have access to all of it.

RE: How is Bootloader copied to RAM

Aadishri GS — Thu, 25 Apr 2019 10:55:37 GMT

Thanks. But, why is there a mention of RAM address range in Memory region? Please refer the image I have attached

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 10:52:53 GMT

No, the bootloader simply "jumps" to the application's start address in flash.

RE: How is Bootloader copied to RAM

Aadishri GS — Thu, 25 Apr 2019 10:49:06 GMT

Sorry, something = Bootloader. Is the question clear? I inferred from the fact that Application is copied from flash area to RAM for execution

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 09:28:25 GMT

I don't understand your question. Where did you get that information that "something" is copied to RAM?

RE: How is Bootloader copied to RAM

Aadishri GS — Thu, 25 Apr 2019 09:25:56 GMT

I understand that only Flash is persistent. I wanted to know if it is copied to RAM before execution on reset and if yes, does the MBR have instruction ready to copy

RE: How is Bootloader copied to RAM

Andy — Thu, 25 Apr 2019 08:56:07 GMT

The bootloader is stored persistently in flash, not in RAM.