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FAQ_MA35D1_RAM Size in Linux is Different from Hardware

Posted: 05 Dec 2022, 18:12
by ytliu6
RAM Size in Linux is Different from Hardware, because VC8000 decoder and display driver reserve some memory
You can check it from U-Boot and Linux device tree
For example, you can see the Linux kernel device tree below
Display driver reserve 48 MB and VC8K reserve 24 MB, so Linux cannot see all the memory space in system
Moreover, OP-TEE also reserve some memory

ma35d1.dtsi

Code: Select all

reserved-memory {
        #address-cells = <2>;
        #size-cells = <2>;
        ranges;
        display_buf: display_buf@0 {
            reg = <0x0 0x8C800000 0x0 0x3000000>; /* 48MiB */
            no-map;
        };
        vc8k_buf: vc8k_buf@0 {
            reg = <0x0 0x8B000000 0x0 0x1800000>; /* 24MiB */
            no-map;
        };
        rproc_buf: rproc_buf@0 {
            reg = <0x0 0x80020000 0x0 0x60000>; /* 384KB */
            no-map;
        };
    };
#MA35D1 #DDR Size #Memory