How to use SDRAM in secure FOTA function of Secure Bootloader(SBL)?

[CainePark]

I'm trying to implement secure FOTA using Secure Bootloader(SBL) & Secure Firmware(SFW).

I referenced '7.4 Secure FOTA' in MCUOTASBLSFWUG.pdf.

In the guide, when I check 'Enable ROM to verify sbl' , 'XIP_BOOT_HEADER_ENABLE' value is set to 0.

So I can't use SDRAM function.

I don't know the reason why the 'Secure FOTA' function disable the SDRAM function.

Please let me know how to use SDRAM function in 'Secure FOTA'.

[GottiLuca]

Hi,

I've faced the same situation and the simplest solution I've found was to initialize the SDRAM "manually" by a function.

You can use as a reference the code in NXP SDK : i.e. : <sdk_root>\boards\evkmimxrt1064\driver_examples\semc\sdram .

In particular see the function BOARD_InitSEMC() in file semc_sdram.c . 

[CainePark · Accepted solution]

I applied the example you provided and confirmed that SDRAM access worked normally after secure booting.

Thank you for your help!