Starterware/AM3352: Board name in SRAM

yingjie gu

Part Number: AM3352

Tool/software: Starterware

Hi,

In sdk 3.0.0.4, u-boot/include/configs/am335x-evm.h, ftdfile is selected by checking the board_name, e.g A335x_SK or A33515BB. I want to let the u-boot download mydt.dtb. I am working on am3352. What is the board_name for am3352 supposed to be?

I looked into the u-boot/board/ti/am335x/board.c and other files, and find out the board_name is read from NON_SECURE_SRAM_IMG_END - SZ_1K.

Is the board_name field pre-set , or I need to modify somewhere to edit the board_name?

Thanks.

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

On AM335x EVM boards the board name is read from on-board EEPROM. If your board does not have an EEPROM you need to skip the EEPROM checks and hardcode the values you want.

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

Intellectual 810 points

Hi Biser,
Thanks.
By digging into the u-boot codes, I find out this field is stored in 0x4030B800 - SZ_1k, which, according to the memory map in TRM, is for SRAM and L3 OCMC.
If you mean this SRAM, yes I do have it.
Where in the u-boot codes can I set the board_name?

0 Kemal R. Shakir over 8 years ago in reply to yingjie gu

TI__Guru 55345 points

Hello yingjie,

At U-Boot console execute:

=> setenv board_name A335X_SK

also check this expression how the device tree gets selected.

findfdt=if test $board_name = A335BONE; then setenv fdtfile am335x-bone.dtb; fi; if test $board_name = A335BNLT; then setenv fdtfile am335x-boneblack.dtb; fi; if test $board_name = BBG1; then setenv fdtfile am335x-bonegreen.dtb; fi; if test $board_name = A33515BB; then setenv fdtfile am335x-evm.dtb; fi; if test $board_name = A335X_SK; then setenv fdtfile am335x-evmsk.dtb; fi; if test $board_name = A335_ICE; then setenv fdtfile am335x-icev2.dtb; fi; if test $fdtfile = undefined; then echo WARNING: Could not determine device tree to use; fi;

Best regards,
Kemal

0 yingjie gu over 8 years ago in reply to Kemal R. Shakir

Intellectual 810 points

Hi Kemal,

How can I hardcode this to the SRAM?

0 Kemal R. Shakir over 8 years ago in reply to yingjie gu

TI__Guru 55345 points

You better hard code it in U-Boot as in this thread.

0 yingjie gu over 8 years ago in reply to Kemal R. Shakir

Intellectual 810 points

Hi Kemal,

The link you provided didn't show how to change the value in the EEPROM, it shows how to changed the read-out value.

Since I only care about the dtb file that my u-boot will use, I changed the am335x-evm.h and remove all the if test statement and set the fdtfile = my dtb.

I am still curious about how to change the eeprom board-name, but project timeline is tight, I have to pick an easier way.

If you have other suggestion, please post in this thread, and I appreciate it.

0 Kemal R. Shakir over 8 years ago in reply to yingjie gu

TI__Guru 55345 points

You can try to change the EEPROM board name from U-Boot console as described in this post or by using the Starter Ware Diagnostic Tool if you need its source code it is available at this link. U-Boot's eeprom command is also a variant .

You can see the Starter Kit's and EVM's EEPROM memory layouts at these links:
processors.wiki.ti.com/.../AM335x_Starter_Kit_ID_Memory_Programming
processors.wiki.ti.com/.../AM335x_General_Purpose_EVM_HW_User_Guide

This code sets the board_name from EEPROM if available:

board/ti/common/board_detect.c

void __maybe_unused set_board_info_env(char *name)
{
	char *unknown = "unknown";
	struct ti_common_eeprom *ep = TI_EEPROM_DATA;

	if (name)
		setenv("board_name", name);
	else if (ep->name)
		setenv("board_name", ep->name);
	else
		setenv("board_name", unknown);

	if (ep->version)
		setenv("board_rev", ep->version);
	else
		setenv("board_rev", unknown);

	if (ep->serial)
		setenv("board_serial", ep->serial);
	else
		setenv("board_serial", unknown);
}

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Starterware/AM3352: Board name in SRAM