6.4.1. barebox DT aliases

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

/ {
     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 a /chosen/barebox,bootsource-${bootsource}${bootsource_instance} property:

 / {
      aliases {
              mmc0 = &sdmmc0;
              mmc1 = &sdhci;
      };

      chosen {
              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.