MicroBlaze: How to extract the BRAM Code out of an ELF file?

[musche@dataio.com]

HI We have a MicroBlaze implemented within a Zync. We want to update the program for the MicroBlaze on the fly. The plan is to reload a program within the BRAM without an ELF file loader. Simplest way: Stop MicroBlaze - load new ByteCode into BRAM - Start MicroBlaze. --> How can we extract the ByteCode out of an elf file? Thank you for your help.

[ibaie]

Hi musche@dataio.com

Not sure if I understood properly the complete use case but I would say you can use objcopy to generate the bin file from the ELF so you can load it.

Regards

Ibai

[musche@dataio.com]

Hi Ibai, Can you point me to an example on how to extract the byte code by using object copy. The idea is to upload a new byte code into the MicroBlaze by the processor at run time.

[stephenm · Accepted solution]

So, as Ibai said, you can use the mb-objcopy to convert the elf to binary:

mb-objcopy -O binary executable.elf executable.bin

You can use the -j to copy just certain sections in the ELF. For example, here I copy just the vector sections.

mb-objcopy -O binary -j .vectors.reset -j .vectors.sw_exception -j .vectors.interrupt -j .vectors.hw_exception user_application.elf vector_section.bin

In your application, you could use somew thing similar to the use case here:

https://mcuoneclipse.com/2016/11/01/getting-the-memory-range-of-sections-with-gnu-linker-files/

Then use mb-objcopy to copy just this section to a binary file.