Flashing .hex files

[JonathanCBU]

Hello,

I need to flash .hex files programmatically, and I am already using pylink for RTT viewer stuff so I'd like to keep using the same library.

Now, JFlashLite can flash a hex file using the GUI without any issue, but the flash_file method doesn't seem to work (I'm assuming that's because of the address encoding within hex files).

When attempting to flash using Jlink.flash_file(<hex_file>, 0) I see the UI appear, but it never moves past erasing, and it always crashes with JLinkFlashException: Programming error occured.

Is there a recommended method for flashing hex files? If not, Is the next best thing parsing the file and flashing it in byte chunks?

[hkpeprah]

You can use intelhex to read in the HEX file to a bytes array, then use .flash() to flash it:

import intelhex

ih = intelhex.IntelHex()
ih.fromfile('myfile.hex', format='hex')
data = ih.tobinarray()

[JonathanCBU]

Ahhh I see, and then I should be able to flash that whole set of data starting at adder 0?

[hkpeprah]

Yup!

[JonathanCBU]

That method definitely made a flash-able bin array (although I needed one more step of data_list = data.tolist()).

Unfortunately though, the .erase() function does not seem to reliably work reliably. It did work a few times, but I cannot pinpoint what is changing between attempts. Per this discussion I am making sure the Jlink is halted before erasing, but I do not always see that erasing happens.

Here is how I am setting up my Jlink.

import pylink
import intelhex

jlink = pylink.JLink()
jlink.open(<jlink_sn>)
jlink.set_tif(pylink.enums.JLinkInterfaces.SWD)
jlink.connect(<chip_name>)

ih = intelhex.IntelHex()
ih.fromfile(<hex_file>, format='hex')
data = ih.tobinarray()
d_list = data.tolist()

# in an python session I would confirm jlink.halted() returns true before continuing
jlink.halt()

current_mem = jlink.memory_read(0, len(d_list))

# here I would see the JLink UI flash on screen for less than a second and the function would return 0
jlink.erase() 

 # should be a list of 255 but instead returns the same thing as current_mem
erased_mem = jlink.memory_read(0, len(d_list))

# fails if erased_mem is not a list of 255 (fails with "ValueError: Invalid error code: -3")
jlink.flash(d_list, 0)

Note: The only times I have seen .erase() work I have had to run it twice and it still returned 0, but other times I have tried running it upwards of 10 times without seeing it work.

[hkpeprah]

Do you have the debugging logs? The logs that print to the Python logger? Sometimes, the CPU isn't halted properly due to something else on the device waking it up.