6.4.1. barebox DT aliases

barebox can use the properties in the /aliases node to arrive at deterministic names for devices, e.g.:

.. code-block:: none

/ {

aliases {

mmc0 = &sdhci; wdog0 = &iwdg;

};

};

will assign the MMC device created from probing the node at &sdhci the name /dev/mmc0. Similarly, the watchdog device created from probing the node at &iwdg will be named wdog0.

By default, barebox will assume the aliases in the DT to align with the bootsource communicated by the firmware. If this is not the case, a device tree override is possible via an /aliases/barebox,bootsource-${bootsource}${bootsource_instance} property:

&{/aliases} {
      mmc0 = &sdmmc0;
      mmc1 = &sdhci;
      barebox,bootsource-mmc0 = &sdhci;
      barebox,bootsource-mmc1 = &sdmmc0;
};

This will ensure that when booting from MMC, /dev/mmc${bootsource_instance} will point at the correct boot device, despite bootrom and board DT alias order being different.