Re: [OpenBIOS] [RFC v2] Pretty-print reg property

[Andreas Färber]

Am 04.11.2010 um 05:05 schrieb Segher Boessenkool:
> > +\ Helpers: Convert number of cells into number of bytes
> > +\ TODO honor cell size, currently assumes 4 (wrong for sparc64)
> > +: my-#acellbytes ( -- #bytes)
> > my-#acells 4 *
> >
> > +;
>
> Device tree property "cells" aren't Forth cells; that's why the
> documentation always talks about "integer as encoded with encode-int",
> i.e., four bytes big-endian twos' complement.

Thanks for clarifying.
> > +: .p-reg ( data len -- )
> > swap >r 0
> > begin 2dup > while
> > dup r@ + c@
> > ( len n ch )
> > pocket tohexstr dup 2 <> if ." 0" then type
>
> : 0.r ( u minlen -- )  0 swap <# 1 ?DO # LOOP #s #> type ;
> and then you can use here:
> 2 0.r
> > 1+
> > dup my-#acellbytes my-#scellbytes + mod my-#acellbytes = if
>
> It is very expensive to use the tree queries in the loop.
> >  ."  "
> > then
> > dup my-#acellbytes my-#scellbytes + mod 0= if
> >  2dup <> if
> >    cr 0 begin ."  " 1+ dup d# 26 >= until drop
>
> 26?  Why that?

Indentation of non-first line, adapted from .properties.
> >  then
> > then
> > repeat
> > 2drop r> drop
> >
> > +;
>
> Maybe something like this:
>
> : .p-reg ( prop len -- )
> > r >r my-#scells my-#acells dup r> r> bounds ?DO
>
> 2dup = IF cr THEN          \ start of line
>  dup 0= IF 2 spaces THEN    \ start of "size" part
>  dup 3 and 0= IF space THEN \ make numbers more readable
>  i c@ 2 0.r                 \ print byte
>  1- 3dup nip + 0= IF drop dup THEN  \ update counter
>  LOOP ;
>
> (untested, mind the bogons).

Leads to:

0 > dev /memory  ok
0 > .properties
name                      "memory"
device_type               "memory"
reg
00   00
00   00
40   00
00   00
N?!H                     -- 5 : 4e 80 04 21 48
available
00   00
40   00
3f   bd
40   00
                           <empty>
  ok

My patch did:

0 > dev /memory  ok
0 > .properties
name                      "memory"
device_type               "memory"
reg                       00000000 40000000
available                 00004000 3fbd4000
  ok

Any hint? My code may have been inefficient but better unstandable for  
a Forth newbie...
> > +\ HELPER: get #size-cells value (from parent)
> > +\ Legal values are 1..4 (we may optionally support longer addresses)
> > +: my-#scells ( -- #size-cells )
> > my-self ?dup if >in.device-node @ else active-package then
> > ?dup if >dn.parent @ then
> > ?dup if
> > " #size-cells" rot get-package-property if 2 exit then
> > \ we don't have to support more than 4 (and 0 is illegal)
> > decode-int nip nip 4 min 1 max
> > else
> > 2
> > then
> >
> > +;
>
> Default for #size-cells is 1, not 2.

Copied from my-#acells. Is it wrong for #address-cells, too?

Andreas