DRA821U: Is it possible to load u-boot on eMMC by SBL

Dejin ZHENG

Part Number: DRA821U

Hi TI,

Our boot flow is : SBL (norflash) -> ATF-TEE (norflash) -> SPL (norflash) -> u-boot (eMMC) -> kernel (eMMC).

Before submit this case, I searched the related questions on E2E. There has success case with u-boot in norflash, not eMMC.

So please help to check weather u-boot can be stored in eMMC?

Thanks.

over 3 years ago

0 Keerthy J over 3 years ago

TI__Guru**** 163230 points

Hi,

There is no support eMMC in SBL. SPL supports the eMMC boot. As per your boot sequence using the SBL the eMMC will not be supported.

- Keerthy

0 Dejin ZHENG over 3 years ago in reply to Keerthy J

Prodigy 60 points

So we also MUST put u-boot into norflash?

+1 Keerthy J over 3 years ago in reply to Dejin ZHENG

TI__Guru**** 163230 points

Hi,

Yes. Since SBL does not support eMMC we have to keep the U-Boot in norflash. If no further questions please click on verify answer.

Best Regards,
Keerthy

0 Dejin ZHENG over 3 years ago in reply to Keerthy J

Prodigy 60 points

Hi Keerthy,

Sorry for more question.

SBL (norflash) -> ATF-TEE (norflash) -> SPL (norflash). In this flow, A72 SPL is loaded, why this SPL cannot load u-boot?

In SPL boot flow, u-boot is booted by tispl.bin. I'm a little confused about this.

+1 Karan Saxena over 3 years ago in reply to Dejin ZHENG

TI__Guru* 77774 points

Hi,

SBL (norflash) -> ATF-OPTEE (norflash) -> A72 SPL (norflash) -> u-boot (eMMC) is possible as SPL has support to load images from eMMC.

The challenge however is that as the bootmode would be OSPI boot mode, SPL by default will look for the u-boot image in the OSPI as SPL reads the boot mode switches to find the boot media to pick the next image.

So the SPL code needs to be modified to pick the u-boot image from eMMC and may need to initialize the eMMC.

There is an FAQ where a similar thing has been done, you can take a look at it:

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1010965/faq-tda4vm-how-to-load-main-core-images-from-emmc-with-boot_app

Regards

Karan

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DRA821U: Is it possible to load u-boot on eMMC by SBL