u-boot and ethernet MAC address from eeprom

[skorolcz]

Hello,
For Petalinux 2018.3 and Zynq board TE0715-04-15-2I with  TE0701-06 , reading MAC address from EEPROM works perfect using:
in project-spec/meta-user/recipes-bsp/u-boot/files/platform-top.h
#define CONFIG_ZYNQ_EEPROM
#ifdef CONFIG_ZYNQ_EEPROM
#define CONFIG_SYS_I2C_EEPROM_ADDR_LEN  1
#define CONFIG_CMD_EEPROM
#define CONFIG_ZYNQ_EEPROM_BUS          0
#define CONFIG_ZYNQ_GEM_EEPROM_ADDR     0x50
#define CONFIG_ZYNQ_GEM_I2C_MAC_OFFSET  0xFA
#endif
This is  solution from Trenz Reference_Design. On Petalinux 2019.1 petalinux-build failed. I am guessing that CONFIG_CMD_EEPROM is the reason. Using petalinux-config -c u-boot I've disabled DM_I2C becouse it is in conflict with CMD_EEPROM but this is not enought for passing petalinux-build successfuly.

How to read MAC address from eeprom on early booting stage for petalinux 2019.1 ?

[JH]

Hi,

for 19.1 and newer check uboot config. -->petalinux-config -c u-boot

We will skip 19.1. Next update will be 19.2 with Vitis, there I will check if it works with uboot config.

br
John

[skorolcz]

I'v got the solution. For PetaLinux 2019.1

/project-spec/meta-user/recipes-bsp/u-boot/files/platform-top.h

added:

#define CONFIG_I2C_EEPROM
#define CONFIG_SYS_I2C_EEPROM_ADDR 0x50
#define CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW 0x0
#define CONFIG_ZYNQ_GEM_I2C_MAC_OFFSET 0xFA



/project-spec/meta-user/recipes-bsp/device-tree/file/system-user.dtsi

/include/ "system-conf.dtsi"
/ {
chosen {
bootargs = "earlycon";
stdout-path = "serial0:115200n8";
xlnx,eeprom = &eeprom;
};
};

&i2c1 {
eeprom: eeprom@50 { /* u88 */
compatible = "atmel,24c08";
reg = <0x50>;
};
};

Now MAC is taken from EEPROM. This solution should works in 19.2. Please let me know if this will help you.

Stefan

[JH]

Hi,

thanks!

It works also with 19.2 --> tested on TE0820 module.
PS: instead add define in platform-top.h you can also use Uboot config: --> petalinux-config -c u-boot
But at the end it's the same :-)

br
John

[EtienneAlepins]

Hi John,

Can you tell me what options in "petalinux-config -c u-boot" I need to activate for TE0820 to get U-Boot to read the MAC address from the EEPROM? It generates a random one by default. I use PetaLinux 2025.1.

Thanks,
Etienne

[M Kirberg]

CONFIG_DM_RTC=y
CONFIG_NVMEM=y

need to be activated for uboot to pick up the mac (DM_RTC needed because of driver bug in 2023.2 as far as I know)

[EtienneAlepins]

Hi,

Thanks M Kirberg, but I already have those enabled in project-spec/meta-user/recipes-bsp/u-boot/files/bsp.cfg

#for reading mac address from eeprom via devicetree entry
CONFIG_NVMEM=y
#needed for nvmem driver because of bug in uboot
CONFIG_DM_RTC=y

However, it does not work. Every time I reboot the TE0820, U-Boot has a new random MAC address. The comment above says "via devicetree entry": is there some manual change I must make in the device tree to get this working?

[M Kirberg]

Hi,

can be that petalinux sets local-mac-address that overrides the devicetree.


/delete-property/ local-mac-address;

in the gem helped in that cases

[EtienneAlepins]

Hi,

Adding the following to project-spec\meta-user\recipes-bsp\device-tree\files\system-user.dtsi fixed it:

&gem3 {
    phy-handle = <&phy0>;

    nvmem-cells = <&eth0_addr>;
    nvmem-cell-names = "mac-address";

    //required otherwise petalinux gives a static address here
    /delete-property/ local-mac-address;

    phy0: phy0@1 {
        device_type = "ethernet-phy";
        reg = <1>;
    };
};

&i2c0 {
    eeprom: eeprom@50 {
        compatible = "microchip,24aa025", "atmel,24c02";
        reg = <0x50>;
           
            #address-cells = <1>;
            #size-cells = <1>;
            eth0_addr: eth-mac-addr@FA {
              reg = <0xFA 0x06>;
            };
        };
};

Thanks.