AM3354: Sysboot configuration issues

Sujay Arasegowda

Part Number: AM3354

Hi,

In my custom design of AM3354 board i would like to have Boot config as MMC, UART and Ethernet.

i have tried Below configurations

SL #	Configuration resistor values [15:0]	Boot sequence				Remarks
SL #	Configuration resistor values [15:0]	1	2	3	4
1.	0100XXXX00110111 (default and working boot mode)	MMC0	SPI0	UART0	USB0	Default and working
2.	0100XXXX00111001 b	SPI0	MMC0	EMAC1	UART0	Not Working
3.	0100xxxx00110110 b	SPI0	MMC0	UART0	EMAC1	Not working
4.	0100xxxx00111100 b	MMC1	MMC0	UART0	USB0	Not working

Above configurations taken from Technical reference manual.

Sl # 1 used was the default which is working fine( showing “CCCC” for UART boot mode),

But we wanted to use configurations which had MMC, UART and Ethernet. So we tried remaining configurations as shown above (Sl # 2,3,4).

For Sl# 2,3,4 configurations, we tested UART boot process but we couldn’t see the “CCCCCC” in tera term itself.

We are trying for EMAC as boot media because, we have MMC on the board where in the later case becomes the boot media.

For the 1st time writing the image to MMC, flashing has to be done. We are unable to do it without EMAC as boot sequence as said in the below link for Linux

http://processors.wiki.ti.com/index.php/Sitara_Uniflash_Flash_Programming_with_Linux

Note: USB0 is NC in our board and its not routed out to use.

Please help us on this?

Regards

Sujay A

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

For the non-working configurations: do you have anything connected to the boot sources preceding the one you want to boot from?

0 Sujay Arasegowda over 8 years ago in reply to Biser Gatchev-XID

Intellectual 660 points

Hi Biser,

MMC is connected (Which we want to use as a boot media in future), no image flashed into it yet. Ethernet is also connected.

Regards
Sujay A

0 Biser Gatchev-XID over 8 years ago in reply to Sujay Arasegowda

TI__Guru**** 393215 points

Please note that EMAC boot timeout is very long, something like 3-4 minutes, so UART will not be available before this timeout expires. If you have an eMMC on MMC1, this will also prevent UART boot.

0 Aditya Teja Damera over 8 years ago in reply to Biser Gatchev-XID

Prodigy 185 points

Hi Biser,
Yes, you are right, but according to the given boot mode in table Configuration no. 3 has EMAC has last boot media. So waiting for 3 to 4 min need not be required and UART0 should have responded

Regards,
Aditya

0 Vinaykumar Hooli over 8 years ago in reply to Biser Gatchev-XID

Prodigy 10 points

Hi ,

eMMc is connected on MMC0.

0 Biser Gatchev-XID over 8 years ago in reply to Vinaykumar Hooli

TI__Guru**** 393215 points

This would prevent the ROM code from trying the next boot sources. Are you aware that if you intend to boot from eMMC it should be connected to MMC1? There are restrictions for booting from eMMC on MMC0, which are outlined in section 26.1.8.5.2 of the AM335x TRM Rev. P.

0 Sujay Arasegowda over 8 years ago in reply to Biser Gatchev-XID

Intellectual 660 points

Hi Biser,

From the TRM it says, if the higher Boot memory is used (i.e >4GB) then to go for MMC1.

In our design we restricted memory size to 4GB for MMC0 for booting.

i guess that should not be a problem. Please help on this.

4GB MMC used in our design is THGBMDG5D1LBAIL - PFA datasheet of the MMC usedTHGBMHG6C1LBAIL_THGBMDG5D1LBAIL.pdf

Regards
Sujay A

0 Biser Gatchev-XID over 8 years ago in reply to Sujay Arasegowda

TI__Guru**** 393215 points

Please read my entire post:

"This would prevent the ROM code from trying the next boot sources"

0 Sujay Arasegowda over 8 years ago in reply to Biser Gatchev-XID

Intellectual 660 points

Hi Biser,

but for configuration 0100XXXX00110111 - its working fine - ie, MMC0, SPI, UART0, USB0.

For this configuration, we were able to boot using UART.

The above said configuration ( 0100XXXX00110111) works fine, but other configurations are not working.

Any way to change the ROM code to check for next boot source?

Regards
Sujay A

0 Biser Gatchev-XID over 8 years ago in reply to Sujay Arasegowda

TI__Guru**** 393215 points

No, there is no way to change the ROM code. What you say suggests that something may be wrong with the other configurations. Have you checked the SYSBOOT pin voltage levels in each of the failing configurations? Do you change only SYSBOOT[4:0]? Check whether there are other SYSBOOT pins involved, that need to be changed for the failing configurations.

0 Sujay Arasegowda over 8 years ago in reply to Biser Gatchev-XID

Intellectual 660 points

Hi Biser,

I have checked for the Failing configuration pin voltage level - High is 3.3V and Low is 0V captured from the scope.

Considering default configuration (0100XXXX00110111) - for the dont care terms we are providing Low Input ie. Default configuration [15:0] = 0100000000110111 b.

Same way for for other Boot configurations dont care terms we are providing Low input ( refered TRM). But still its not working.

Regards
Sujay A

0 Sujay Arasegowda over 8 years ago in reply to Biser Gatchev-XID

Intellectual 660 points

0 Biser Gatchev-XID over 8 years ago in reply to Sujay Arasegowda

TI__Guru**** 393215 points

No, there is no way to change ROM code.

For #2, how long did you wait for the CCCC... string? EMAC timeout is quite long, several minutes, and UART will not be tried before the EMAC timeout expires.

0 Biser Gatchev-XID over 8 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

As a suggestion, can you remove the eMMC from the board and check what happens?

0 Sujay Arasegowda over 8 years ago in reply to Biser Gatchev-XID

Intellectual 660 points

Hi Biser,

Since MMC is BGA type. its hard and takes more time to remove the MMC. Please suggest.

Regards
Sujay A

0 Biser Gatchev-XID over 8 years ago in reply to Sujay Arasegowda

TI__Guru**** 393215 points

I don't have any other ideas. Since this is your specific hardware, we have no way to replicate this and investigate.

0 Mohana Prashantha over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Hi Biser,
But for SL#3 configuration (0100xxxx00110110 b ), Boot sequence is SPI0,MMC0,UART0 and EMAC1.
It means,in the sequnce UART0 is prior to EMAC1 booting and how can UART0 wait for EMAC1?

Regards,
Mohan

0 Biser Gatchev-XID over 8 years ago in reply to Mohana Prashantha

TI__Guru**** 393215 points

I don't have any other ideas. Since this is your specific hardware, we have no way to replicate this and investigate.

0 Mohana Prashantha over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Hi Biser,

Please find the updates below.

Observation was – For configurations other than Default,

- we need to wait around 4-4.5 minutes for Console to show “CCCC” characters

- Characters “CCCC” appears for 8-10 times and checks for other boot media, Later it goes for UART again

Also, please find the attached file for detailsAM3354_Boot issues.docx

Thanks,

Mohan

0 Biser Gatchev-XID over 8 years ago in reply to Mohana Prashantha

TI__Guru**** 393215 points

OK, this is absolutely normal behavior.

0 Mohana Prashantha over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Thank you Biser for your reply

But, when it enters in UART boot mode and i am trying to follow the below procedure to transfer the "u-boot-spl.bin" as per the procedure mention in the below link:

http://processors.wiki.ti.com/index.php/AM335x_U-Boot_User’s_Guide#UART

Switch ON EVM with switch settings for UART boot. When “CCCC” characters appear on TeraTerm window, from the File Menu select Transfer --> XMODEM --> Send (1K mode)
Select “u-boot-spl.bin” for the transfer
After image is successfully downloaded, the ROM code will boot it.
When “CCCC” characters appear on TeraTerm window, from the File Menu select Transfer --> YMODEM --> Send (1K mode)
Select “u-boot.img” for the transfer
After image is successfully downloaded, U-Boot will boot it.
Hit enter and get to u-boot prompt “U-Boot# ”

This procedure work perfect with only Serial No: 1 configuration mentioned in the table present in the previous post. This same procedure is not working for any other configuration.

Regards,

Mohana

0 Biser Gatchev-XID over 8 years ago in reply to Mohana Prashantha

TI__Guru**** 393215 points

Mohana Prashantha said:
When “CCCC” characters appear on TeraTerm window, from the File Menu select Transfer --> YMODEM --> Send (1K mode)

After you send the SPL you must immediately send the u-boot.img. You must not wait for CCC..., as this means that the processor has rebooted. The wiki you refer is old, please follow processors.wiki.ti.com/.../Linux_Core_U-Boot_User's_Guide

0 Mohana Prashantha over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Hi Biser,
We have also tried, File Menu select Transfer --> YMODEM --> Send (1K mode)
It is also not successful.It behaves same as XMODEM

Thanks,
Mohan

0 Biser Gatchev-XID over 8 years ago in reply to Mohana Prashantha

TI__Guru**** 393215 points

I am forwarding this to a person who knows more details about ROM code behavior. He will respond directly here.

0 Mohana Prashantha over 8 years ago in reply to Biser Gatchev-XID

Intellectual 340 points

Thank you

0 Mohana Prashantha over 8 years ago in reply to Mohana Prashantha

Intellectual 340 points

Hi Biser,

Any updates from your team?

Thanks,

Mohan

0 Biser Gatchev-XID over 8 years ago in reply to Mohana Prashantha

TI__Guru**** 393215 points

Feedback will be posted by them directly here when available.

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AM3354: Sysboot configuration issues