Running out of memory?

RE: Running out of memory?

butch — Thu, 30 Mar 2017 13:23:23 GMT

I suggest you use debugger to understand the crash. Assume the 'crash' is infinite loop in the default hardfault handler. Pause the program and examine the registers to see whether the stack pointer is invalid. Or some other general purpose register (as a pointer into the heap) is invalid. Where invalid means: out of range of real memory addresses. You might need a basic understanding of assembly language and the ARM architecture. I think there are two sets of registers (for the main context and the interrupt/handler context) and you might need to examine the main context, i.e. where your app was when the hardfault occurred.

RE: Running out of memory?

Jonathan — Mon, 27 Mar 2017 23:58:16 GMT

I've tripled check, static in a class means "one global instance, regardless of how many objects you allocate". "ld" is the GNU linker, as far as I know I'm using armlink. Technically I haven't allocated 0 heap, I've got some heap, I'm trying to get a lot more, but my goal isn't either to use heap. I'm just trying to solve my crash. I gave it a lot of thoughts over the weekend and realized it may also be a stack overflow issue.

RE: Running out of memory?

butch — Thu, 23 Mar 2017 16:09:48 GMT

I'm not familiar with Keil. I use the linker script file .ld to specify zero heap. What I am asking is: do you intend to have zero use of the heap and specify that somewhere? I don't think the compiler knows that you have allocated zero heap (in the linker script), and will generate code to use the heap. AFAIK, static doesn't mean you can only have one instance, it means "not on the heap".

RE: Running out of memory?

Jonathan — Thu, 23 Mar 2017 14:52:43 GMT

Oh and sorry, not static because I want to be able to use other instances of the object.

RE: Running out of memory?

Jonathan — Thu, 23 Mar 2017 14:51:19 GMT

Heap is allocated thru the scatter file (using Keil) I don't know of another way to allocate it when not having a arm_startup_nrf51.s . Unless I'm mistaken, "this" will be allocated during compilation. Looking at the map file, the bigger my object is, the bigger my zero-init section is (specifically, the ZI section of my main.o increases with the size of the object). So I would conclude my object is definitely not on the heap.

My hypothesis is not valid and was that maybe the SD would allocate something dynamically and run out of memory. All I know is the issue doesn't happen if my object is smaller.

RE: Running out of memory?

butch — Thu, 23 Mar 2017 13:26:42 GMT

What architectural reason? I am not sure about it either, but if the properties are not static, they are accessed through a "this" pointer, and I wonder where and when they are allocated. You did not answer whether you have allocated any heap. What is your hypothesis about when and why the hard fault occurs?

RE: Running out of memory?

Jonathan — Thu, 23 Mar 2017 10:30:10 GMT

No I don't want them static (for architecture reasons). Members properties might be on the heap, indeed, though afaik that's not how it works. I do have some heap allocated in my scatter file, but my own code should not allocate anything on the heap, and as far as I understand neither does the SD.

RE: Running out of memory?

butch — Wed, 22 Mar 2017 15:35:49 GMT

Maybe you need "static" on the data members of the class e.g "static Otp OTP". That is, maybe the data member instances are on the heap. Also, are you saying that you have no heap allocated in your linker script, so that you will get a hard fault if the compiler generates any code that uses the heap?