SK-AM62: eMMC UDA redundant boot

Lit Zhi Chee

Part Number: SK-AM62

Hi,

Previously I successfully flashed the 3 files into eMMC boot partitions #1 and #2. To change to flash into boot#2, I change the dfu_alt_info_emmc to mmcpart 2 instead of 1 as shown in the code below.

For flashing into boot#1

setenv dfu_alt_info_emmc 'rawemmc raw 0 0x800000 mmcpart 1;rootfs part 0 1 mmcpart 0;tiboot3.bin.raw raw 0x0 0x400 mmcpart 1;tispl.bin.raw raw 0x400 0x1000 mmcpart 1;u-boot.img.raw raw 0x1400 0x2000 mmcpart 1;u-env.raw raw 0x3400 0x100 mmcpart 1;sysfw.itb.raw raw 0x3600 0x800 mmcpart 1'

For flashing into boot#2

setenv dfu_alt_info_emmc 'rawemmc raw 0 0x800000 mmcpart 2;rootfs part 0 1 mmcpart 0;tiboot3.bin.raw raw 0x0 0x400 mmcpart 2;tispl.bin.raw raw 0x400 0x1000 mmcpart 2;u-boot.img.raw raw 0x1400 0x2000 mmcpart 2;u-env.raw raw 0x3400 0x100 mmcpart 2;sysfw.itb.raw raw 0x3600 0x800 mmcpart 2'

1. I am trying to flash tiboot3.bin, tispl.bin and u-boot.img into eMMC UDA partition from Linux host. How do I do that?

2. I have tried flashing from SD card following this thread TDA4VM: Does tda4vm support emmc UDA partition boot ? - Processors forum - Processors - TI E2E support forums, but when I boot from UDA, the SDK only boots R5 BL / SPL. Is the UDA only capable of reading / booting R5 BL? Or can it boot into u-boot?

3. After flashing from SD card to mmc dev 0 0, it seems like /dev/mmcblk0p1 is gone, so my rootfs in the partition is gone as well. Why does this happen?

over 3 years ago

0 Hong Guan64 over 3 years ago

TI__Guru* 79930 points

Hello Chee,
In AM62x Linux SDK, eMMC is partitioned by default:
- boot partition (#1/#2) as raw for boot binary
- UDA as ext4 for root_fs
software-dl.ti.com/.../UG-Memory.html
Will you elobrate your user case?
Best,
-Hong

0 Lit Zhi Chee over 3 years ago in reply to Hong Guan64

Prodigy 170 points

Hi Hong,

What I am trying to do is I want to set primary boot mode as eMMC and backup boot mode as eMMC UDA.

In this thread SK-AM62: If eMMC boot0 fails to boot, uboot will automatically boot from boot1 - Processors forum - Processors - TI E2E support forums, you mentioned that "When eMMC is configured as UDA-raw by BOOTMODE pins, RBL does support redundant/recovery boot from the primary offset @0x0 OR the redundant offset @0x400000 from UDA-raw."

So is it possible to flash the boot binary files (tiboot3.bin, tispl.bin and u-boot.img) to the primary offset? If yes, what are the steps? Are steps similar to how I flash into eMMC boot partition?

Also, if I flash the boot binary files to UDA, do I need to create another partition in UDA so that the files do not overwrite the rootfs?

0 Hong Guan64 over 3 years ago in reply to Lit Zhi Chee

TI__Guru* 79930 points

Hello,
Even though it is possible in RBL, but there's practical usage limitations to use redundant/recovery boot from UDA-raw mode due to the fact that 0x0 offset collides with MBR/GPT partition table in UDA.
Best,
-Hong

0 Dominic Rath over 3 years ago in reply to Lit Zhi Chee

Mastermind 7800 points

Hi,

as Hong explained your issue is that UDA raw mode boot is problematic because the partition tables overlap with the "primary" boot offset 0x0.

If you're looking for UDA raw mode boot because you want to have the backup boot offset capability you can't have MBR/GPT partitions in the UDA.

What you could do is partition your eMMC flash to have a "large" general purpose partition and reduce the UDA partition to only 16-32 MB (i.e. just enough to hold primary and backup U-Boot with tiboot3.bin, tispl.bin and u-boot.img each). Within the general purpose partition you can then have a MBR/GPT partition table at offset 0 and your filesystems.

Please note that this requires source code changes to U-Boot. I also haven't tested this extensively yet, but it did work on a first device.

Regards,

Dominic

0 Lit Zhi Chee over 3 years ago in reply to Dominic Rath

Prodigy 170 points

Thanks for the feedback.

For the general purpose partition, is there any reference on how to create or implement it?

+1 Hong Guan64 over 3 years ago in reply to Lit Zhi Chee

TI__Guru* 79930 points

Hello Chee,
Due to extra porting efforts, plus the fact that 0x0 offset collides with MBR/GPT partition table in UDA. I don't think using UDA-raw is a practical option for redundancy boot.

Thanks Dominic for your valuable input here.

Best,
-Hong