AM335x Custom Board Detection and Boot up.

sanjay shekar

Other Parts Discussed in Thread: AM3352

Hello,

We have a custom board developed based on AM335x reference. The SYSBOOT is configured as 10011 (NAND. NANDI2C, MMC0, UART).

We are using UART0 as the console, When we power on the board with SD card having the test image (U-Boot or Diagnostic Image from TI) nothing comes in the console. Same Image works on Evaluation board EVM3358-SK-LCD.

The Baud Rate is 115200 8N1.

We have no USB port on this custom board, only UART0 is available.

Even if no SD card is inserted to the custom board, the board do not print "CCCC" .

Now to check if the board is properly working, is there any tool to detect the board for its working ??

Any Flash Tool Available for AM335x (Its AM3352) based processor. ??

Is there any mechanism to run the test program from RAM or NAND ??

Please let me know if any other mechanism.

Regards,

Sanju.

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi Sanju,

From what you describe it seems like your processor does not start. You should begin by checking the power supplies, oscillators and reset signals.

0 sanjay shekar over 9 years ago in reply to Biser Gatchev-XID

Intellectual 330 points

Hello Biser,
Thanks for the quick reply,
The Reset button in the board is pulled up to VCC, Oscillator is 24Mhz, The power button is fed to Power mangement IC as per reference schematic. So now, is there any way where I can detect if the IC is getting powered on properly and boot ROM code is executing ?? OR can I detect the IC using some tool (Flashing tool)??

Regards,
Sanju.

0 Biser Gatchev-XID over 9 years ago in reply to sanjay shekar

TI__Guru**** 393215 points

ROM code is probably not executing, otherwise you would see the CCCC.. string on your terminal. Can you try changing the boot sequence, pushing MMC and UART to be first boot devices? Do you have a JTAG interface on your board?

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

TI__Guru**** 393215 points

Check this wiki too: http://processors.wiki.ti.com/index.php/AM335x_board_bringup_tips

0 sanjay shekar over 9 years ago in reply to Biser Gatchev-XID

Intellectual 330 points

Boot Sequence cannot be changed, no Jumper or switch given. Yes, we do have JTAG interface !! anything can be done with JTAG ??

Regards,
Sanju.

0 Biser Gatchev-XID over 9 years ago in reply to sanjay shekar

TI__Guru**** 393215 points

Please check the wiki link I posted above.

0 sanjay shekar over 9 years ago in reply to sanjay shekar

Intellectual 330 points

Thanks for your reference Biser. We had an issue with UART port.

We were supposed to use Direct TTL signals instead of which we were using via RS232. Now we are able to see CCCC prints.

But, the test program is not executing on the custom board. When I insert the MMC card with test Image loaded, nothing comes up in console. Not even CCCCC prints. (Again the same Image is working on Eval board as mentioned before.)

Please suggest us wat next :)

Regards,
Sanju.

0 Biser Gatchev-XID over 9 years ago in reply to sanjay shekar

TI__Guru**** 393215 points

I don't think the Starter Kit Diagnostics will run on your board. I suggest you go directly and try and boot Linux. You should be able to see at least the initial SPL message.

Anyway at this point it seems that your system is coming up fine, processor boots and ROM code executes.

Another thing that you will need to do if you have DDR3 memory on your board is to tune the DDR parameters. These wiki guides should be followed: http://processors.wiki.ti.com/index.php/AM335x_EMIF_Configuration_tips and http://processors.wiki.ti.com/index.php/AM335x_DDR_PHY_register_configuration_for_DDR3_using_Software_Leveling These is also a step-by-step tutorial how to do this here: http://processors.wiki.ti.com/index.php/Sitara_Linux_Training:_Tuning_the_DDR3_Timings_on_BeagleBoneBlack

0 sanjay shekar over 9 years ago in reply to Biser Gatchev-XID

Intellectual 330 points

Thanks Biser, you are awesome !!!!
I don know why Diagnostic code wont work..

But, I tried Booting Linux and I got some SLP logs as told by you.. :) Below is the logs from board. It is searching some board ID from EEPROM.

U-Boot SPL 2013.01.01 (Apr 04 2013 - 23:46:57)
Could not probe the EEPROM; something fundamentally wrong on the I2C bus.
Could not get board ID.
Unknown board, cannot configure pinmux.### ERROR ### Please RESET the board ###

Regards,
Sanju.

0 Biser Gatchev-XID over 9 years ago in reply to sanjay shekar

TI__Guru**** 393215 points

That's exactly why the diagnostics won't work. All TI EVM boards have an EEPROM on them, which is read several times during boot in order for the boards to be configured properly. If you don't have an EEPROM on your board you can simply bypass these checks.

Anyway, this now means that SPL has been loaded into internal SRAM and execution has been passed to it. You will now need to configure DDR memory, pinmux and so on.

0 sanjay shekar over 9 years ago in reply to Biser Gatchev-XID

Intellectual 330 points

Thanks ... Yes, I will continue exporing on this.. I see few post on bypassing EEPROM. But I do have EEPROM on our board.

Regards,
Sanju.

0 Biser Gatchev-XID over 9 years ago in reply to sanjay shekar

TI__Guru**** 393215 points

Where is it located? It must be on I2C0 with slave address 0x50 to be directly recognized. EEPROM type is CAT24C256 on the AM335X EVM boards. You can see details for EEPROM data layout here: http://processors.wiki.ti.com/index.php/AM335x_Starter_Kit_ID_Memory_Programming

0 sanjay shekar over 9 years ago in reply to Biser Gatchev-XID

Intellectual 330 points

yes, the IC used is AT24C02C and the slave address is 0x50. But this is located in I2C1 bus. Not in I2C0 Bus.

Any easy configuration changes in my U-Boot code??

Regards,
Sanju.

0 Biser Gatchev-XID over 9 years ago in reply to sanjay shekar

TI__Guru**** 393215 points

I'm afraid I am not a SW expert, but basically you will need to initialize I2C1 (same way as I2C0 is initialized) and redirect the EEPROM queries to I2C1.

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

Intellectual 360 points

Hi Biser
I am trying to write to NAND flash via UART by following the below url:

processors.wiki.ti.com/.../AM335x_U-Boot_User's_Guide

I bypassed the EEPROM Check in my custom Board by commenting the eeprom check in "u-boot-2014.xx.xx.xxxxx/board/ti/am335x/ board.c" file.
We are using AM3352 Processor.

How ever when I trying to send the code via UART usin Tera Term I am getting the below error
Unknown board, cannot configure pinmux.### ERROR ### Please RESET the board ###
There after it hangs on.

I believe we need to modify the mux configuration as per your previous comment. And we think that would be in
"u-boot-2014.xx.xx.xxxxx/board/ti/am335x/ mux.c"

But I am confused regarding that. Can you please help me out.

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