TMDS64GPEVM: Mac address and emprom

Hi,

The EEPROM is not necessary for a board design. As you mention you will need to modify the u-boot source code for your board to remove the eeprom board check code. TI uses the eeprom to store MAC addresses and the board ID so u-boot knows which DDR config to use and which dtb to load for the Linux kernel. 

I am surprised at the moment that you cannot read the board data. Which SDK are you using? And which version of the EVM are you using?

Best Regards,

Schuyler

Hi,

Try this to see what is in the eeprom I am assuming that you have a gp evm and not an SK evm. Stop the boot in u-boot. These are u-boot commands.

i2c dev 0

i2c md 0x50  0.2 100

This  should display the eeprom contents.

Best Regards,

Schuyler

Thanks , i am now able to print the contents of emprom using the uboot`s i2c commands but i cannot print/dump the contents of  eprom using  linux/i2c-tools . 

Am i doing something wrong ?

i also want to know which part of source code that i need to remove to make the bootloaders  independent from eprom , in other words i want to hard code the the DDR and mac address in uboot. 

Hi,

In Linux try this command:

i2cdump -f -y 0 0x50 c

To answer the u-boot source code question, which SDK are you using? I want to make sure I am looking at the same SDK you are.

Best Regards,

Schuyler

Hi,

In linux when i type the  "i2cdump -f -y 0 0x50 c" and i get following output ;

root@am64xx-evm:~# i2cdump -y 0 0x50
No size specified (using byte-data access)
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 55 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff U...............
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
20: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
40: 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
50: ff ff ff ff ff ff ff ff ff 00 ff ff ff ff ff ff ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
80: 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
90: ff ff ff ff ff ff ff ff ff 00 ff ff ff ff ff ff ................
a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................

I am using the tisdk-base-image-am64xx.tar.xz based image which is a part of latest sdk 8.21

Hi,

I thought you might be using a GP-EVM, are you using an SK-EVM? This is the dump looks like on my board which is a gp-evm. Please note that the board I have is a pre-production board and the MAC-IDs stored here are not valid. For a the SK-EVM the command changes slightly in that the I2C address is 0x51 and not 0x50 in the example that I showed.

Do you have your DDR designed yet?

Best Regards,

Schuyler

I am using the gp evm..

I have also tried with ox51 but i2c dump is still invalid .

But the surprising part is that using the uboot i2c commands that you have shared earlier I can seen valid id's,  values stored on eprom on 0x50 address. 

Any update ?

On SKEVM, I2C-0 pins are not selected/muxed in device-tree, could be the same case for GP-EVM. Don't know how it read anything... 

Adding block shown below to device-tree, compiling..., got the SKEVM I2C-0 working in Linux

&main_pmx0 {
	main_i2c0_pins_default: main-i2c0-pins-default {
		pinctrl-single,pins = <
			AM64X_IOPAD(0x0260, PIN_INPUT_PULLUP, 0) /* (A18) I2C0_SCL */
			AM64X_IOPAD(0x0264, PIN_INPUT_PULLUP, 0) /* (B18) I2C0_SDA */
		>;
	};
};

&main_i2c0 {
	pinctrl-names = "default";
	pinctrl-0 = <&main_i2c0_pins_default>;
	clock-frequency = <100000>;
};