i.MX8MP Memory Device Tree Configuration

[Wobaffet]

Hello, For our custom board, we'll have 512MB LPDDR4 MT53E128M32D2DS-046 from micron. In the EVK DT, 6GB memory configured as follows:

        memory@40000000 {
                device_type = "memory";
                reg = <0x0 0x40000000 0 0xc0000000>,
                      <0x1 0x00000000 0 0xc0000000>;
        };

According to memory mapping from Reference Manual of the processor DDR addressing is like this:

So can I configure for our board like this:

        memory@40000000 {
                device_type = "memory";
                reg = <0x0 0x40000000 0 0x20000000>;
        };

or do I need to configure like this?

        memory@40000000 {  
                device_type = "memory";
                reg = <0x0 0x40000000 0 0x10000000>,
                      <0x1 0x00000000 0 0x10000000>;
        };

[Dhruvit · Accepted solution]

Hi @Wobaffet,

I hope you are doing well.

One can define memory node for 512MB LPDDR4 DRAM in dts as below.

memory@40000000 {
      device_type = "memory";
      reg = <0x0 0x40000000 0 0x20000000>;
};

Additional changes are also required for 512MB DRAM in u-boot-imx.

In the board configuration header file. (/include/configs/..)

#define PHYS_SDRAM 0x40000000
#define PHYS_SDRAM_SIZE 0x2000000

Please refer to 5.7 Adding OP-TEE support for a new board in i.MX Porting Guide and change CFG_DDR_SIZE (if op-tee is used.)

Thanks & Regards,
Dhruvit Vasavada