AM4377: emmc boot fail with gpt partition

Hello SI,

I am not sure whether AM437x actually supports GPT formatting. The AM335x & AM437x Technical Reference Manual chapter "Initialization > Functional Description > Memory Booting > MMC/SD Cards" only mentions MBR formatting. Let me ask around.

In the meantime, are there any error logs we would be able to look at?

Regards,

Nick

Hello SI,

One final clarification. The ROM does not support GPT formatting. However, that does not necessarily mean that you couldn't use GPT formatting for partitions that the ROM does not use.

Post Rom code - Payload Interface question does a deep dive into some of those concepts. It looks like there are some other non-TI resources on the web that discuss this subject as well. For example, webpage BeagleBone Black booting also discusses using GPT formatting on AM335x media. Future readers, note that TI does not guarantee that information found on non-TI webpages is accurate or up-to-date.

Regards,

Nick

Hi Nick,

Thanks for clarification.

Then, could you please help how customer can make a MBR partition on U-BOOT for bootable image on emmc?

When I checked U-BOOT UG, it seemed there is only GPT partition described as below.

Thanks and Best Regards,

SI.

Hello SI,

Could you go into more detail about what you are looking for? In your first post, it sounded like the customer already knows how to create MBR partitions.

Regards,

Nick

Hi Nick,

I meant partitioning on U-BOOT. my customer has no idea how they can make MBR partition in U-BOOT.

They made MBR partition on Linux PC before, but they need to do this to develop FW update with partitioning script on U-BOOT.

Thanks and Best Regards,

SI.

Hello Sung,

Give me a couple of days to check on this. Please ping me if I have not replied by the middle of next week.

Regards,

Nick

Hello SI,

As far as I can tell, there is not currently support to add MBR partitions from U-Boot. It looks like U-boot expects MBR partitions to have been already made.

We kind of addressed the subject of GPT on EMMC in my reply on September 23 above. However, I am still digging to see if I can find TI documentation for using eMMC as a boot device when there is a gpt table on it. Ping me next week if I have not come back with more information.

Regards,

Nick

Hi Nick,

Have you check more details for GPT on EMMC at AM437x?

Thanks and Best Regards,

SI.

Hello SI,

It looks like there was another customer who recently wrote GPT tables to their EMMC and was able to boot at post Am3352. Their method seems pretty similar to EMMC flashing documentation that phytec published: AM57xx: Flashing Images to eMMC. I am going to try to run experiments tomorrow.

Regards,

Nick

Hello Nick,

Have you checked it in your experiments?

Thanks and Best Regards,

SI.

Hello Nick,

Any update on this?

Thanks and Best Regards,

SI.