topic Re: S32K118 noinit RAM in S32 Design Studio

S32K118 noinit RAM

YuepengWang — Sat, 26 Sep 2020 05:22:32 GMT

Hello NXP,

I have a question when I am trying to implement bootloader of S32K118, please give me some help.

First of all, I have defined the ".noinit" section in the linker file ,from 0x200057C0 to 0x200057FF.

Then, I have defined two pointer variables(uint32_t) like this:

uint32_t * pProgrammingReqFlag = (uint32_t *)0x200057c0;
uint32_t * pApplicationValidity = (uint32_t *)0x200057c4;

And the values in these addresses will be checked after reset(you will find in "main.png").

The question is: when I downloaded this project into hardware ,it works well, but if I reset the hardware (power off and power on), it do not work any more !

How to access the .noinit section ? or is there anything else need to be modified in the linker file?

Re: S32K118 noinit RAM

YuepengWang — Sat, 26 Sep 2020 05:36:26 GMT

BTW, if these two variables point to any other address which is not located into the .noinit section, it works well after power on.

uint32_t * pProgrammingReqFlag = (uint32_t *)0x200027c0;
uint32_t * pApplicationValidity = (uint32_t *)0x200027c4;

Re: S32K118 noinit RAM

YuepengWang — Mon, 28 Sep 2020 03:24:31 GMT

It is resolved by modifying the initializer of ecc-ram.

Re: S32K118 noinit RAM

lukaszadrapa — Tue, 29 Sep 2020 12:08:12 GMT

Hi,

yes, ECC is the key point.

And let me share recommended procedure to retain SRAM content across reset:

Regards,

Lukas

Re: S32K118 noinit RAM

YuepengWang — Wed, 30 Sep 2020 06:26:05 GMT

Hi Lukas, thank you for your information !