Hikey-620 System Memory Map

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#1

Greetings,
Referring the Hikey (LeMaker) Hardware User Manual v0.1 2015, it mentioned that there is a LPDDR part ‘K4E8E304EE-EGCE’ 1GB memory. But I dont see any description of the complete system memory map. My question is:

  • Is there is location where I can get the system memory map for Hikey620

  • Referring to the Linux kernel source and DTS file, to understand the memory map: arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts
    {{{
    /*
    * Reserve below regions from memory node:
    *
    * 0x05e0,0000 - 0x05ef,ffff: MCU firmware runtime using
    * 0x05f0,1000 - 0x05f0,1fff: Reboot reason
    * 0x06df,f000 - 0x06df,ffff: Mailbox message data
    * 0x0740,f000 - 0x0740,ffff: MCU firmware section
    * 0x21f0,0000 - 0x21ff,ffff: pstore/ramoops buffer
    * 0x3e00,0000 - 0x3fff,ffff: OP-TEE
    */
    memory@0 {
    device_type = “memory”;
    reg = <0x00000000 0x00000000 0x00000000 0x05e00000>,
    <0x00000000 0x05f00000 0x00000000 0x00001000>,
    <0x00000000 0x05f02000 0x00000000 0x00efd000>,
    <0x00000000 0x06e00000 0x00000000 0x0060f000>,
    <0x00000000 0x07410000 0x00000000 0x1aaf0000>,
    <0x00000000 0x22000000 0x00000000 0x1c000000>;
    };

      reserved-memory {
              #address-cells = <2>;
              #size-cells = <2>;
              ranges;
    
              ramoops@0x21f00000 {
                      compatible = "ramoops";
                      reg = <0x0 0x21f00000 0x0 0x00100000>;
                      record-size     = <0x00020000>;
                      console-size    = <0x00020000>;
                      ftrace-size     = <0x00020000>;
              };
    

}}}

I want to understand the system memory map.
Thanks in advance.
Warm Regards,
Raghu


#2

Yep. That’s pretty much it (all other RAM not on the list in DT will be used by the kernel). If you are interested in the kernel virtual memory map see: https://www.kernel.org/doc/Documentation/arm64/memory.txt .