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Bootloader Source

PostPosted: Tue Dec 16, 2014 10:42 am
by bjpirt
Hi All,
Does anybody know if the bootloader source is available anywhere? I'd love to use it as a starting point for some modifications I've got in mind. Also, it would be nice to silence it during boot to stop it spewing out boot messages.
Cheers,
Ben

Re: Bootloader Source

PostPosted: Tue Dec 16, 2014 3:23 pm
by RogerClark
What do you mean by bootloader ?

Basically, AFIK none of the SDK libs or other low level code is available as source.

The only way to modify it would probably be to disassemble the SDK modify the assembler code and re-assemble.

Or if you just want to stop that message, you could probably find the bytes and replace with zeros to terminate the string.

Re: Bootloader Source

PostPosted: Tue Dec 16, 2014 3:42 pm
by Sjaak
RogerClark wrote:What do you mean by bootloader ?

Basically, AFIK none of the SDK libs or other low level code is available as source.

The only way to modify it would probably be to disassemble the SDK modify the assembler code and re-assemble.

Or if you just want to stop that message, you could probably find the bytes and replace with zeros to terminate the string.


There is a rom inside the chip that sets up the gpio's, mmc and spi and boots from there. You won;t find it in the SDK..

here is a dump/disassembly of it: viewtopic.php?f=13&t=214&hilit=disassembly


Still unknown if it is reprogrammable (prolly not).

Re: Bootloader Source

PostPosted: Thu Dec 18, 2014 8:27 am
by bjpirt
What do you mean by bootloader ?


I mean the bit of code that boots first and then decides which user program to run. I'm probably going to write my own but it would be good to have a place to start from

There is a rom inside the chip that sets up the gpio's, mmc and spi and boots from there. You won;t find it in the SDK..


Hmm, hopefully that's not the piece of code that's dumping stuff to the serial port because that sounds like it will be tricky to upgrade if not impossible.

So it sounds like there is no source available :-( Will have to ask Espressif nicely...

Cheers,
Ben