Build with optimization does not work with DFU

[Akbar Dhanaliwala]

Hi, I'm using IAR ARM Embedded Workbench (v7.20) to build my Nordic applications. Recently I enabled optimizations (in Project Options: C/C++ Compiler:Optimizations: Level-High-Size). However, when I try to DFU this build it always fails. DFU-ing it works fine when I build my application with optimizations set to None. My guess is that there is a struct or some other data object that is getting optimized that needs to exist at a specific memory location for the DFU to work, but I'm not really sure. Any ideas on why DFU would fail with optimizations turned on? thanks! akbar

[Nikita]

I don't quite understand what do you mean. If you compile your bootloader without optimization then DFU works fine, but if you compile it with optimization then DFU fails? How exactly DFU fails? You not able to discover DFU or some troubles when you try to load your application with DFU?

[Akbar Dhanaliwala]

This is what I'm doing step by step:

1. Open nrf Toolbox v1.9.1 on an Android Device running 4.4.4

2. In DFU-> Select File->DropBox->select application.hex file

3. Select Device-> Choose DfuTarg

4. Upload -> Says: Connecting...->Starting DFU...->Update Failed: Remote DFU Not Supported (3)

-akbar

[Nikita]

What version of softdevice and SDK do you use? And what DFU project do you use?

[Akbar Dhanaliwala]

Softdevice s110 v7.0 DFU from SDK6.0

[scytulip]

I think optimization cannot be applied to any code which relies on hardware performance.

For example, in the API call of nrf_delay_ms, it runs multiple NOP instructions to achieve 1ms unit delay.

In my opinion, if you optimize your code, the compiler may reduce this "redundant" function but totally mess up the timing of your program.