Greetings,
I develop the boot-loader and kernel for a family of boards that have an on-board EEPROM which contains information as to what options are physically loaded on the board such as memory size/config, and peripheral IC's. We allow customers to create special builds of our standard products with sub-loaded components and while each combination of options ends up with a unique model number, it seems silly to create a different static device-trees for each possible option (not to mention we don't create the unique model number until an order is placed).
My approach has been to define a per-baseboard device-tree in Linux for a 'fully loaded' board, then remove nodes which the EEPROM claims are not present in the bootloader before it passes the DTB to the kernel. I do this by defining aliases in the device-tree for the peripherals that are 'optional' so that the bootloader itself does not need to know the details about how the device is connected.
Is it more appropriate for the bootloader to 'remove' nodes for devices that are not physically present or should I be setting their status property to 'disabled' instead? I'm not clear if either option really has any pros or cons.
Thanks for any suggestions or comments,
Tim
Tim Harvey - Principal Software Engineer Gateworks Corporation 3026 S. Higuera St. San Luis Obispo CA 93401 805-781-2000