SStar memory layout

SStar平台上特有的memory layout方式

DDR total memory = linux memory(cat /proc/meminfo的MemTotal) + mma(mma_heap_name0 + MMU_MMA) + kernel reserved

 

LX_MEM 是总内存64M，Kernel reserve 5M，所以正常可以使用的内存是59M

 

 

 

LX_MEM里的MMP HEAP,类似linux的cma，这部分内存是给MI SYS通过软件的方式动态分配给HW IP使用的内存池, 是给通用的HW IP使用， MMAP是专用的HW IP使用，比如摄像头或显示屏使用

 

分配内存大小，通过修改dts文件

/ {
    model = "INFINITY2M SSC011A-S01A-S";
    compatible = "sstar,infinity2m";

    /* memory setting will be replaced with LX_MEM*/
    memory {
        reg = <0x20000000 0x03E00000>;
    };
    /* this cmdline will be replaced with uboot bootargs*/
    chosen {
        bootargs = "console=ttyS0,115200n8r androidboot.console=ttyS0 root=/dev/mtdblock2 init=/linuxrc cma=4m";
    };

    /*!!IMPORTANT!! The reserved memory must be 1MB aligned*/
    reserved-memory {
        #address-cells = <1>;
        #size-cells = <1>;
        ranges;

        /*cma0 {
            compatible = "shared-dma-pool";
            size = <0x400000>;
            reusable;
            alignment = <0x1000>;
            linux,cma-default;
        };*/
    };

};

 

 

参考链接:

https://wx.comake.online/doc/doc/IKAYAKI_ZH/customer/development/reference/memory_layout.html#2-mmap

https://wx.comake.online/doc/syg27dk2rkls-SSD20X/customer/development/software/Px/zh/sys/mma.html

https://blog.csdn.net/wind0419/article/details/117332471