The 0x1212120c could be a red herring. This value is as you say placed onto the stack of a task when the task is created. Once the stack has been unwound the value will just be left in memory and will legitimately be used by other variables. It looks like an 8 bit type (set to 0c) is using the same memory location.
Is it possible that the task causing the error is corrupting something? Have you created a large buffer or array as a stack variable or something like that.
From the information so far there is nothing obviously wrong so it is difficult.
Could one of your exception mode stacks be clashing with your task stack?
Try to examine the heap area (maybe fill the empty area with a known value to see if any of it is getting corrupted). Also if you single step through the part of the code where the abort is occurring then you may be able to provide more details.
its the weirdest thing… I’ve stepped through every function, isr and macros I went through and found that I was crashing exactly after I’ve gone into Task4… right there for some reason isAlnum function (which isn’t called anywhere in my code) gets called (traced in assembly) before any variable declares… and from there it crashes.
What I’ve done, I’ve created a new file with the same code, did a build clean then compile/make… and wat do u know? it now works…
sorry if i’ve wasted your time guys… next time I’ll try that first (bowing head in shame)