Mbed-os: KL27Z "Unsupported warning"

[ManDeJan]

I am working with mbed OS 5.7.5 and the KL27Z board,
I get an error if I want to compile that says board not supported
It seems the file /targets/targets.json is out dated, I added a "5" to the release versions of KL27Z and everything worked fine. Is there a reason it is not yet updated?

It says here it is supported: https://os.mbed.com/platforms/FRDM-KL27Z/

[0xc0170]

The target was enabled only for mbed 2 (as you noticed).

@MarceloSalazar Can you review please?

[MarceloSalazar]

@maclobdell please review

[maclobdell]

My apologies, I just realized that I had not commented on this. During testing, this platform was found to run out of memory with some Mbed OS 5 tests with GCC_ARM compiler. It worked fine for IAR and Arm compilers, which are optimized more for small memory footprint. The KL27Z passed tests with Mbed 2 configuration without RTOS, which uses less memory. This is why the platform was marked as Mbed Enabled for Mbed 2 only.

[ManDeJan]

Hi, thanks for the response. After editing targets.json and enabling Mbed OS 5 it worked fine for me with the gcc-arm compiler toolchain. Though I needed to turn on -Os optimizations. Building the following code for the KL25Z target gives a 45K binary. Building it for the KL27Z gives a 53K binary.

#include "mbed.h"

int main() {
    DigitalOut led_pin(LED1);
    while (true) {
        led_pin = 1;
        wait_ms(500);
        led_pin = 0;
        wait_ms(500);
    }
}

These are very similar chips and such a simple program as above shouldn't result in a binary 8 kilobytes larger. After inspecting both binarys I found the KL27Z target contains an additional 115 symbols, I am suspecting most of these functions are simply not marked as inline and are not necessary. Here are the symbols for both projects: https://pastebin.com/3jgPRqbi (kl27z) https://pastebin.com/vBV8UFxm (kl25z).

[ciarmcom]

ARM Internal Ref: MBOTRIAGE-249

[0xc0170]

My apologies, I just realized that I had not commented on this. During testing, this platform was found to run out of memory with some Mbed OS 5 tests with GCC_ARM compiler. It worked fine for IAR and Arm compilers, which are optimized more for small memory footprint. The KL27Z passed tests with Mbed 2 configuration without RTOS, which uses less memory. This is why the platform was marked as Mbed Enabled for Mbed 2 only.

This issue will be closed. The question was answered.

@ManDeJan If you still have an issue or question regarding KL27Z , please create a new issue