TDA4VM: It is possible to load kernel by uboot spl?

Hi,

Karan Saxena said:

other wang said:

SBL -> A72 ATF/OPTEE -> A72 SPL -> A72 u-boot -> A72 Linux Kernel

With this boot flow you can keep SBL, tifs and A72 SPL and u-boot in OSPI. Then u-boot can boot the kernel image and other remote core firmwares from the filesystem. (eMMC or SD card)

I just realised that you already have this boot flow realised on your side.

other wang said:

     Could we load kernel by uboot spl ? 

Can you please help me understand that why are you looking for this requirement and how would this benefit your usecase? A72 SPL is meant to be very lightweight and hence doesn't suit the requirement for booting Linux.

Regards

Karan

Hi,  

    Our kernel size is 16M , our flash size is 32M  and  we need AB area for safe boot . So there isn't enough space to save kernel to flash.

    1. Does the SBL support zImage?

    2. Could you give me a patch to use uImage instead of the Image? 

Regards

Karan Saxena said:

Can you please help me understand that why are you looking for this requirement and how would this benefit your usecase? A72 SPL is meant to be very lightweight and hence doesn't suit the requirement for booting Linux.

We are try to reduce the boot time ,  and I found the uboot-spl need more than 400ms during boot  and uboot iss more than 500 ms.

On our boot flow, the  ddr was inited by SBL, and both of the u-boot spl and uboot are not necessary in combined_appimage. 

So It is possible to load kernel from emmc and load the kernel ot ddr ram ? 

Or SBL load uboot to ram directly from flash and boot kernel from emmc?

Thanks.

Hi Wang,

other wang said:

So It is possible to load kernel from emmc and load the kernel ot ddr ram ? 

SBL does not support eMMC. So if the kernel Image needs to be picked from from eMMC we definitely need U-Boot. Since you
have a small flash we have suggested this bootflow of going all the way till U-Boot & U-Boot can load kernel from eMMC.

other wang said:

On our boot flow, the  ddr was inited by SBL, and both of the u-boot spl and uboot are not necessary in combined_appimage. 

It is needed for loading the Kernel from eMMC as SBL cannot load from eMMC.

Karan Saxena Feel free to add if i missed something.

- Keerthy