RTOS: How to read image data from flash using Null Src Usecase

Hello Neha,

Current null source link doesnt support reading from flash. I guess this was mostly because of size limitation as keeping large video/image data in flash wont be possible/feasible. So no use-case as such to refer to.

You can try one of below

1. Read from flash the input (image) data into DDR during use-case init and use null source link with "memory read" mode. This way you dont have to change link. you can refer to any qspi read/write application in VSDK.

2. Add reading from flash support in the null source link. You would need to modify links_fw\src\rtos\links_common\network_rx\networkRxLink_drv.c and networkRxLink_tsk.c files.

Hope this helps.

Hi Neha,

1. For QSPI flash you can use QSPI flash writer utility.
2. You should read in memory mapped mode.
3. Yes you can use these APIs.
4. You can refer to the TRM or header file.

Regards,
Rishabh

Hello Neha,

As writing image to flash is one time activity, you can combine that with bootloader and application (VSDK) flashing. The tools used for those can be used for flashing image as well. For reading flashed image into DDR you can use QSPI lib APIs.

Also other alternative (and recommended) is to make image data (C-array) as a part of VSDK so you dont need to flash and read it separately and reading would be done by SBL for you.

If you prefer the above approach you need to only understand the null source use-case and refer to any existing use-case for that.
In other case refer to QSPI flash writer application source code from PDK which uses PDK QSPI lib. Also refer to SBL user-guide for flashing process.

Lastly in both cases, i would suggest you to get "nullsrc(memory read)-> Decode -> VPE -> Display part working first.
This is simple as null source readily supports memory read mode.