topic Get stack pointer of interrupted task in MQX Software Solutions

Get stack pointer of interrupted task

hbouch — Tue, 15 Nov 2016 15:40:04 GMT

Hello,

Is it possible to get the address of the instruction that will be executed first upon a return from interrupt?

Actually, we would like to know the address of the last executed instruction before SWT watchdog is trigger. This address is saved in a part of RAM that is not initialized at startup and thus can be read by the application during initialization. But since MQX switches stack for interrupt, I'm wondering if there is a way to read the stack of the task that was interrupted.

Thanks,

Hugo

Re: Get stack pointer of interrupted task

danielchen — Tue, 22 Nov 2016 06:05:05 GMT

From the ARM architecture reference.

This is for arm,I think the concept is similar to other processors.

Regards

Daniel

Re: Get stack pointer of interrupted task

hbouch — Fri, 25 Nov 2016 11:55:08 GMT

Hello Daniel,

Thanks for your answer. However, R13 and R14 will contain the SP and LR of the ISR. The LR should contain the return address to _int_kernel_isr.

I'm sure there is a way of reading the saved registers (in the kernel data maybe ?) to see the value of R13 and R14 registers but how?

Regards,

Hugo