SK-AM62: Boot partition 1 as primary boot mode and UDA as backup boot.

Hi,

A few questions,

1. Are you using TI EVM?
2. What PSDK are you using?
3. Does your board boot using eMMC boot mode? (Boot from hardware Boot0 partition).

~ Judith

Hi, 

1. Yes, Im using TI EVM AM62x

2. Im using ti-processor-sdk-linux-am62xx-evm-08.04.01.03

3. Using eMMC boot mode. Boot from boot1 partition as primary boot mode and UDA as backup boot mode.

~ Hong

Hi,

There might be an issue booting from eMMC hardware boot partition on AM62x. Can you please try the following patch as an experiment: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1233869/faq-am625-how-to-boot-with-emmc-boot-mode-on-am62x

~ Judith

Hi,

By refer to your link, its about the issue booting from eMMC hardware boot partition. But my question is, do we have any method that I can boot from UDA(backup boot mode) if boot1(primary boot mode) fail? The only way to switch from Boot1 to UDA is only to set the partconf manually, but I need it to switch automatically.
The output is shown in the picture, it success to switch to UDA(backuo boot mode) when I erase boot partition 1, but it stuck at SPL

Hi Hong,

ROM should switch to backup boot mode automatically if we fail to boot from primary boot mode. U-boot then copies boot index info (information whether ROM booted from primary vs secondary media) from ROM. So here ROM will first try to boot from eMMC Boot0 partition, if not successful, it will boot from UDA. This information is then copied to U-boot which will continue booting from the boot mode that worked for ROM.

~ Judith

So U-boot does not have the functionality to decide whether to choose primary boot media or secondary boot media, only ROM does. Once ROM decides which boot mode works, U-boot will continue booting with that boot mode.

~ Judith

In summary, backup boot method should work automatically.

That being said, if you look at Table 5.3.1.2 of the AM62x TRM, there is a list of all the possible backup boot modes. Since MMCSD Boot (eMMC Boot using UDA) is not specified, it may not be supported as a backup boot mode.

I will verify on my end and post here soon.

~ Judith

Ya, ROM switch to backup boot mode automatically, but it just only boot SPL as I mention before.

Hi Hong,

As mentioned above:

-- If you look at Table 5.3.1.2 of the AM62x TRM, there is a list of all the possible backup boot modes. Since MMCSD Boot (eMMC Boot using UDA) is not specified, it may not be supported as a backup boot mode.

Is there a reason you need to use eMMC boot using UDA, given that it is not listed as a backup boot mode?

~ Judith

Just need to have a backup image if image in boot partition 1 is corrupted.
Im now able to boot from UDA, but it stuck at SPL.
Another thing is, I had followed your step to modify the configs file, but it has warning during build:


And I need to confirm again, Im now flashing image into boot partition 1 boot mode(primary) and UDA boot mode(backup), is it the changes only make in boot partition 1?

Hi Hong,

Just need to have a backup image if image in boot partition 1 is corrupted.
-- Understood, my concern is booting from UDA is not listed as backup boot mode and may not been verified as backup boot mode.

Im now able to boot from UDA, but it stuck at SPL.
-- Is this the log you showed above? That is issue with U-boot. It seems that ROM has booted from UDA successfully. Is it the whole log? It seems to have stopped at ATF. I would verify the image that you flashed to UDA.

Another thing is, I had followed your step to modify the configs file, but it has warning during build:
-- My understanding is that CONFIG_SYS_MMC_ENV_PART=1 is to save to BOOT0, but you are using this for eMMC boot, so if you change to CONFIG_SYS_MMC_ENV_PART=2, you should be able to use:
setenv mmcdev 0
setenv bootpart 0:2
saveenv
boot 

Im now flashing image into boot partition 1 boot mode(primary) and UDA boot mode(backup), is it the changes only make in boot partition 1?
-- Can you rephrase the question?


I will go ahead and try this on my end and get back to you today.

~ Judith

Since you are using eMMC boot mode, please apply the first patch in this link: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1233869/faq-am625-how-to-boot-with-emmc-boot-mode-on-am62x and re-build u-boot binaries before flashing to eMMC Boot0 partition.

~ Judith

Correction: My mistake, I did not boot from the correct boot mode.

I tried again: SW2:001010000 SW3:11010010 after
mmc partconf 0 1 1 1
mmc bootbus 0 2 0 0
setenv bootpart 0:2
saveenv

and ran into tispl.bin not found error. It seems we cannot boot with UDA fs mode, only UDA raw mode. I believe if we set up to boot from UDA in raw mode, it should work.

Actually this might be a bug in U-boot, but for now, UDA in raw mode should work.

~ Judith

Hi Judith,

Thanks for your guide, may I know, these two changes in (+) [FAQ] AM625: How to boot with eMMC boot mode on AM62x - Processors forum - Processors - TI E2E support forums:
1. Re-build U-boot with the following eMMC patch,
2. In Linux Kernel, rebuilt the DTB with the following patch,

I need to make changes for both boot partition 1 and UDA or just only UDA?

I had tried your method, I erase image in boot partition 1(primary), it can switch and boot from UDA(backup), but still stuck at SPL:

By referring the result above, it's only the way I can boot from UDA by using the step below:
1. Switch to boot mode boot 1.
mmc partconf 0 1 1 1 
mmc bootbus 0 2 0 0

2. Set partconf to UDA:
mmc partconf 0 1 7 1
mmc bootbus 0 2 0 0

Then my image can boot normally from UDA(backup).
=

I'm now able to boot from emmc Boot1 and UDA. What I need is, when my image in boot partition 1 is corrupted or I switch the boot mode pin, it will automatically boot from the desire boot mode without set partconf again and again.

This is my changes in ks-am62-main.dtsi, may you help me to check if I'm doing wrong, because my original content has some different with yours:

Yes Hong,

What I need is, when my image in boot partition 1 is corrupted or I switch the boot mode pin, it will automatically boot from the desire boot mode without set partconf again and again.

-- Yes, ROM needs to fail booting from BOOT0 in order for it to boot UDA and then U-boot will simply copy this "working" boot method and continue booting with it.


This is my changes in ks-am62-main.dtsi, may you help me to check if I'm doing wrong, because my original content has some different with yours:

-- Your DTS changes look good, in summary:

If you have the following, remove them:
ti,otap-del-sel-mmc-hs = <0x0>;
ti,otap-del-sel-ddr52 = <0x5>;
tti,otap-del-sel-hs200 = <0x5>;

and add these:
/delete-property/mmc-ddr-1_8v;
/delete-property/mmc-hs200-1_8v;

~ Judith

Hi,

I have question here:

/configs/am62x_evm_a53_defconfig
-CONFIG_SYS_MMC_ENV_PART=1
+CONFIG_SYS_MMC_ENV_PART=2

a. What will happened if I make these changes?
b. What does each number in the code represent?
0 is represent UDA?
1 is represent Boot 1?
2 is represent Boot 2?

Hi Hong,

CONFIG_SYS_MMC_ENV_PART specifies which MMC partition the environment is stored in. If not set, defaults to partition 0, the user area. Common values might be 1 (first MMC boot partition), 2 (second MMC boot partition).

Since we are using first hardware boot0 partition for eMMC boot, CONFIG_SYS_MMC_ENV_PART=2 changes environment to hardware boot1 partition.

For more information, you could look at <path-to-ti-u-boot>/env/Kconfig --> config ENV_IS_IN_MMC.

~ Judith

Hi Judith,

I need to use Boot 1 as primary boot mode and UDA as backup boot mode, how can I configure the CONFIG_SYS_MMC_ENV_PART?
0 is represent UDA?
1 is represent Boot 1?
2 is represent Boot 2?