This post originated from an RSS feed registered with Python Buzz
by Phillip Pearson.
Original Post: Kinetis E and OpenOCD update, and some Kinetis FTMRH flasher code for you
Feed Title: Second p0st
Feed URL: http://www.myelin.co.nz/post/rss.xml
Feed Description: Tech notes and web hackery from the guy that brought you bzero, Python Community Server, the Blogging Ecosystem and the Internet Topic Exchange
Following up on my last post, I managed to get OpenOCD flashing a Kinetis MKE02Z64VLD2 chip, to the point that I could hook it up to Kinetis Design Studio and program/debug almost as easily as with my J-Link, albeit without unlimited flash breakpoints, and it would often get confused about where it was on startup, although after hitting F8 everything would come back to normal.
I posted to the OpenOCD-devel mailing list and got a bunch of responses from others who had been working on the same problem, including Ivan Meleca, who had written a flash driver for the KE02/4/6 series but hadn't had time to upload it. I tested this out tonight on my MKE02Z64VLD2 and MKE04Z8VTG4 boards and it works well, so look forward to seeing that in mainline OpenOCD soon.
Ivan's code works, so I don't want to mess with it, but I'm proud of a couple of little tricks I figured out for my own implementation. I wrote a Python script to process the output of arm-none-eabi-gcc -g -O0 -mcpu=cortex-m0plus -mthumb -c -Wa,-adhln, extract out the opcodes, and comment everything up nicely, which lets you build self-contained routines that are easy to download and run on target devices. I'm not sure how everybody else wrote their flasher code, but they all seem to have ended up with slightly differently formatted hex bytes embedded in C files, so maybe by hand? Anyway, my flash algorithms and C-to-assembly-to-C code are up on GitHub as myelin-mcu-flash.
Next, my esp8266-jtag boards came back from OSHPark, and I soldered one up and connected it to my LPC-Link2, only to find that OpenOCD doesn't support JTAG operations on CMSIS-DAP adapters, only SWD. So I started writing some code to get that working. The next day, someone wrote on OpenOCD-devel that they were trying to do the same thing. So hopefully we can combine efforts and sort it out. I've learned a lot about JTAG in the last few days -- in a nutshell it's a very complicated way to reset a chip and read and write two registers, but it turns out that you can do a *lot* with those building blocks :)
Previous Topic
