• David Gibson's avatar
    [POWERPC] Derive ebc ranges property from EBC registers · b2ba34f3
    David Gibson authored
    In the device tree for Ebony, the 'ranges' property in the node for
    the EBC bridge shows the mappings from the chip select / address lines
    actually used for the EBC peripherals into the address space of the
    OPB.  At present, these mappings are hardcoded in ebony.dts for the
    mappings set up by the OpenBIOS firmware when it configures the EBC
    bridge.
    
    This replaces the hardcoded mappings with code in the zImage to
    read the EBC configuration registers and create an appropriate ranges
    property based on them.  This should make the zImage and kernel more
    robust to changes in firmware configuration.  In particular, some of
    the Ebony's DIP switches can change the effective address of the Flash
    and other peripherals in OPB space.  With this patch, the kernel will
    be able to cope with at least some of the possible variations.
    Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    b2ba34f3
44x.c 1.99 KB