• Max Filippov's avatar
    xtensa: add device trees support · da844a81
    Max Filippov authored
    Device trees allow specification of hardware topology and device
    parameters at runtime instead of hard-coding them in platform setup
    code. This allows running single binary kernel on a range of compatible
    boards.
    
    New boot parameters tag BP_TAG_FDT is allocated and a pointer to flat
    device tree is passed in it.
    
    Note that current interrupt mapping scheme uses single cell for
    interrupt identification. That means that IRQ numbers used in DTS must
    be CPU internal IRQ numbers, not external. It is possible to extend
    interrupt identification to two cells, and use second cell to tell
    external IRQ numbers form internal. That would allow to use single DTS
    on multiple boards with different mapping of external IRQ numbers.
    Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
    Signed-off-by: default avatarChris Zankel <chris@zankel.net>
    da844a81
prom.h 121 Bytes