Occasionally I run into this kind of problem: I have downloaded my application, and it immediately crashes or looses the connection:
What happened?
What is the problem? It is helpful to understand what happens if I press ‘debug’ in CodeWarrior or any other debugger:
Percepio has released a new V2.2.2 library of FreeRTOS+Trace (see Tracing with FreeRTOS+Trace from Percepio). The new release comes with many improvements. The trace recording is optimized for more efficient recording and longer trace with the same amount of memory.
Note: Because the trace data structure is changed and optimized, I need the latest tool on the PC/host from http://www.percepio.com.
I have updated the Percepio Processor Expert component to generate and use the new trace library V2.2.2. This includes the new settings in the component properties as shown below:
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When I create a project with CodeWarrior for MCU using Processor Expert and S08GB60, I’m asked if I want to have a Debug and/or Release configuration:
Debug or Release in Processor Expert
Debug or Release? For an embedded microcontroller? Does this make any sense?
I’m stressing the CodeWarrior debugger a lot: having multiple boards attached, debugging things in parallel, switching and unplugging boards all the time. I have my eclipse IDE running for several days and nights (up to a week or more), with constantly suspending and resuming and switching networks. And sometimes it is my fault (see Device is Secure?). But well, sometimes the CodeWarrior debugger has a problem too. Luckily, a simple trick gets things back on track.
It is one of these long weekends which allow to catch up on many things. One thing I finally completed was the move to FreeRTOS V7.1.1. With this I did some tests using the Tower boards, including the Kinetis one. So I have rebuild my Kinetis K60 application and was ready to flash the device. But then to my surprise I got this dialog:
Device is secure. Erase to unsecure?
Maybe this situation is familiar to you: My embedded software stopped in the field. I am in front of it, hooked up with my laptop and debugger. And I see: indeed, it has a problem. Maybe just a one-time-thing? Maybe I do a reset and things will work as expected? Not really, according to Debugging Rules.
The thing is this: I’m in a situation which requires some deep investigation. But I do not have the time now. Or my boss, the boss-boss or the customer are standing behind me asking all the good questions for which I don’t have an answer. So in this situation it would be great if you could take a dump of the device memory, reset that board, move on and investigate what happened offline? Here are several ways how to do this…
In eclipse and CodeWarrior for MCU10 the usual thing I do is:
If I need to program another board with the same binary, then I download it to that board too. Fine. But what if I want to skip point 1 and 2? What if I do not have or want a project? All what I have (and need) is a binary file, and I want is to flash that file to my boar. By pressing a button.
Sometimes my embedded application is not doing what I want it to do. I can solve many problems with normal ‘step/stop mode debugging‘: setting breakpoints, step, stop, inspect data, and so on. But not always. If a piece of code is changing a global variable unintentionally, I do not know where to set my breakpoint. Something is changing my variable, and I have no clue from where. It could be a dangling pointer, a stack overflow or something similar which I cannot track down with code breakpoints. What I need is a breakpoint on data: watchpoints!
In many cases I do a full erase-flash-debug cycle: I get my embedded microcontroller flash completely erased and then programmed with my application. Well, that does not work that way if I program with a bootloader. Yes, I can flash the bootloader and then load my target application with the bootloader, but that’s not the scenario I want to use in the development phase. I want to flash my application and keep the bootloader on the target. This means: I need to do erase and program a part of the memory. But how to do this?
It happens to me that I run into a really, really nasty problem. I spend hours (if not weeks) to get it resolved. Strong coffee and the problem keeps me up at long nights. I think every embedded system engineer knows what I’m talking about. Yeah, most of the time it is my fault or an oversight. But once in a while I’m convinced that I have found a real bug. Then I report it back to the vendor to fix it. I hope my report will prevent another engineers to run into the same problem. Or that I learn something else as a by-product. Oh yes….
MCU on Eclipse 