Phytec i.MX 93 - Eeprom

i.MX 93 BSP Manual PD24.1.1 Documentation Rev.: imx8mp-pd22.1.2-51-ga548be7d
General I²C1 bus conguration (e.g. imx93-phycore-som.dtsi): https://git.phytec.de/linux-imx/tree/arch/
arm64/boot/dts/freescale/imx93-phycore-som.dtsi?h=v6.1.55_2.2.0-phy3#n88
General I²C2 bus conguration for imx93-phyboard-segin.dts: https://git.phytec.de/linux-imx/tree/arch/
arm64/boot/dts/freescale/imx93-phyboard-segin.dts?h=v6.1.55_2.2.0-phy3#n155 or for imx93-phyboard-
nash.dts: https://git.phytec.de/linux-imx/tree/arch/arm64/boot/dts/freescale/imx93-phyboard-nash.dts?
h=v6.1.55_2.2.0-phy3#n113
7.9 EEPROM
There are two dierent I2C EEPROM ashes populated on phyCORE-i.MX93 SoM and on the phyBOARD-
Segin/Nash i.MX 93. For now only the one on the phyCORE-i.MX93 is enabled, and it is used for board
detection.
7.9.1 I2C EEPROM on phyCORE-i.MX93
The I2C EEPROM on the phyCORE-i.MX93 SoM has its memory divided into two parts.
• normal area (size: 4096 bytes, bus: I2C-2, addr: 0x50)
• ID page (size: 32 bytes, bus: I2C-2, addr: 0x58)
It is possible to read and write from the device populated:
target:~$ hexdump -C /sys/class/i2c-dev/i2c-2/device/2-0058/eeprom
To read and print the rst 1024 bytes of the EEPROM as a hex number, execute:
target:~$ dd if=/sys/class/i2c-dev/i2c-2/device/2-0050/eeprom bs=1 count=1024 | od -x
To ll the whole EEPROM (ID page) with zeros we rst need to disable the EEPROM write protection, use:
target:~$ gpioset 2 21=0
Then the EEPROM can be written to:
target:~$ dd if=/dev/zero of=/sys/class/i2c-dev/i2c-2/device/2-0058/eeprom bs=32 count=1
Warning
The rst 256 bytes of the normal EEPROM area (bus: I2C-2 addr: 0x50) are reserved and should not
be overwritten! (See below)
7.9.2 EEPROM SoM Detection
PHYTEC uses rst 256 bytes in EEPROM normal area to store information about the SoM. This includes
PCB revision and mounting options.
The EEPROM data is read at a really early stage during startup. It is used to select the correct RAM
conguration. This makes it possible to use the same bootloader image for dierent RAM sizes and choose
the correct DTS overlays automatically.
If the rst 265 bytes of the normal area are deleted, the bootloader will fall back to the phyCORE-i.MX93
Kit RAM setup, which is 1GiB RAM.
Accessing Peripherals 60