AM335x MMC boot

Hiroyasu Tazawa1

Guru 12350 points

Hi, Everyone

I have a question about SYSBOOT of AM335x.

We set SYSBOOT[4:0]=11100b.
TRM says this sequence "MMC1/MMC0/UART0/USB0".

but

when we insert MMC0 and MMC1, AM335x boot from MMC0.
when we insert MMC1, AM335x boot from MMC1.

We think MMC1 boot image is boot.

Do you know why MMC1 boot first when we insert MMC0 and MMC1 ?

Best Regards
Hiroyasu

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

I don't understand. "Do you know why MMC1 boot first when we insert MMC0 and MMC1 ?" - is this a typo?

0 Hiroyasu Tazawa1 over 9 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

Thank you for your reply.

My Customer insert MMC0 and MMC1.
but AM335x boot from MMC0.

I wanna know this reason.
Becase SYSBOOT[4:0]=11100b sequence is "MMC1/MMC0/UART0/USB0".

Best Regards
Hiroyasu

0 Biser Gatchev-XID over 9 years ago in reply to Hiroyasu Tazawa1

TI__Guru**** 393215 points

This can only happen if the ROM code doesn't find a valid boot image on MMC1. What do you have on the two cards?

0 Hiroyasu Tazawa1 over 9 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

"What do you have on the two cards?" mean SD card version ?

Best Regards
Hiroyasu

0 Biser Gatchev-XID over 9 years ago in reply to Hiroyasu Tazawa1

TI__Guru**** 393215 points

No, software on the cards.

0 Hiroyasu Tazawa1 over 9 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

I will make sure about this and feedback.

Best Regards
Hiroyasu

0 Hiroyasu Tazawa1 over 9 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

I heard about software.
My customer use same MLO and u-boot of Linux SDK.

MMC0:μSD Card ... MLO and u-boot
MMC1:eMMC ... MLO and u-boot

Best Regards
Hiroyasu

0 Biser Gatchev-XID over 9 years ago in reply to Hiroyasu Tazawa1

TI__Guru**** 393215 points

In your first post you were saying that you boot from card on MMC1. Now you say that you have eMMC on MMC1. Which is correct? Also, how do you confirm that you are actually booting from MMC0, and not from MMC1?

0 Hiroyasu Tazawa1 over 9 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

I'm sorry. I had a mistake.

We use MMC0:μSD and MMC1:eMMC. These are correct.
and Both memory have MLO and u-boot.

both u-boot's base are same.
but these u-boot are slightly difference program.

Best Regards
Hiroyasu

0 Yordan Kamenov over 9 years ago in reply to Hiroyasu Tazawa1

TI__Mastermind 42515 points

Hi Hiroyasu,

can you check if the pins of your board are correctly configured as listed in Table 26-29 of the AM335X TRM.
You can check those threads for issue like yours:

e2e.ti.com/.../366265
e2e.ti.com/.../352951

Regards,
Yordan

0 Hiroyasu Tazawa1 over 9 years ago in reply to Yordan Kamenov

Guru 12350 points

Hi Yordan

Thank you for your comments.
I think Table 26-29 is corect.
becase MMC1 of eMMC boot is success when μSD Card of MMC0 is removed.

and I will make sure target board's pin is correct.

Best Regards
Hiroyasu

0 Hiroyasu Tazawa1 over 9 years ago in reply to Yordan Kamenov

Guru 12350 points

Hi, Yordan

My customers are using same Pins written in TRM Table 26-28 and Table 26-29 .
but They use additional pins about MMC1:eMMC.

MMC1_DAT3(T8)
MMC1_DAT4(U8)
MMC1_DAT5(V8)
MMC1_DAT6(R9)
MMC1_DAT7(T9)
GPIO1_20(R14) for Reset

If these pins are connected, Does these have any probrem ?

Best Regards
Hiroyasu

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