Re: autoconf hack for broken firmware

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Sun, Feb 01, 2026 at 21:10:38 +0100, Julian Coleman wrote:

> My U45 doesn't attach jbus-i2c because the node has:
> 
>   f0096404: /i2c@400,fc62020
>   
>   #address-cells          00000002 ........ ........ ........     2
>   #size-cells             00000000 ........ ........ ........     0
>   compatible              6a627573 2d693263 00...... ........   "jbus-i2c"
>   device_type             69326300 ........ ........ ........   "i2c"
>   name                    69326300 ........ ........ ........   "i2c"
>   reg                     00000400 0fc62020 00000010 ........   ......  ....
> 
> and the reg property is 96-bits wide.  We try to read it as 64-bit
> words, which fails.

I haven't touched OFW in _ages_, but

  "reg" - Standard property name to define the package’s registers.

  prop-encoded-array:
    Arbitrary number of (phys-addr size) pairs.
    phys-addr is a (phys.lo ... phys.hi) list, encoded with encod
    size is a list of integers, each encoded with encode-int.

IIRC what is going on here, then assuming that #address-cells on the
parent is 2 (which is the default and can be omitted), this

   reg 00000400 0fc62020 00000010

looks like two words for phys address and one word for size.

But, again, I haven't touched OFW in ages...


-uwe