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linuxlinux-kernelarmdevice-tree

model field of root node in device tree

I am exploring device tree. Looking at imx6l-sabresd.dts

/dts-v1/;

#include "imx6dl.dtsi"
#include "imx6qdl-sabresd.dtsi"

/ {
        model = "Freescale i.MX6 DualLite SABRE Smart Device Board";
        compatible = "fsl,imx6dl-sabresd", "fsl,imx6dl";
};

There is "model" field in the root node. This field is present in almost every device tree, but when I grep for who is reading this model. Only Freescale CPU machine code is accessing it.. Is this field not compulsory.

jamal@jamal:~/rpi/rpi-build/tmp/work-shared/raspberrypi3/kernel-source$ grep -nr "of_property_read_string(root,"
arch/arm/mach-imx/cpu.c:91: ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
arch/arm/mach-mxs/mach-mxs.c:469:   ret = of_property_read_string(root, "model", &soc_dev_attr->machine);

Can anyone explain the significance of this field.

Solution

  • Searching the Linux source code found me where the model field is used by the Kernel. It is printing the value on the console.

    ./arch/arm/kernel/devtree.c:236:       
 model = of_get_flat_dt_prop(dt_root, "model", NULL);
 pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);