[U-Boot] [PATCH 2/5] port wandboards to use the generic distro configs

Tom Rini
2013-12-06T16:28:54Z

On Fri, Dec 06, 2013 at 04:26:51PM +0100, Wolfgang Denk wrote:
> Dear Dennis Gilmore,
>
> In message <20131206084854.0e0da0cd@adria.ausil.us> you wrote:
> >
> > Wolfgang Denk <wd@denx.de> escribi=F3:
> > > Dear Dennis Gilmore,
> > >=20
> > > In message <1386296295-28658-3-git-send-email-dennis@ausil.us> you
> > > wrote:
> > > >
> > > > - "fdt_addr=0x11000000\0" \
> > > > + "fdt_addr=0x11100000\0" \
> > > > + "fdt_addr_r=0x11200000\0" \
> > >
> > > Why would you need fdt_addr and fdt_addr_r ? This makes no sense.
> > > Two different values would only be needed if there was NOR flash
> > > available where we could read the FDT from without loading it to RAM
> > > first. AFAIK ther ewill never be variants of the Wandboard with NOR
> > > flash, so you will always have to load the FDT to RAM first - thus the
> > > destinction makes no sense.
> >
> > please go and read the cmd_pxe.c file it specifies the use of the two
> > variables. one is for a system provided dtb and the other is for a user
> > provided dtb
>
> But this is crap. The meaning of these variables has been wel-defined
> for a long, long time. "fdt_addr" is the FDT address in NOR flash (or
> similar memory except system RAM); "fdt_addr_r" is the FDT address
> when loaded to system RAM (hence the "_r" in the variable name).

It's a well defined and widely ignored in ARM convention then. We've
got lots of 'fdt_addr' meaning RAM and no 'fdt_addr_r' and then in both
ARM and PowerPC 'fdtaddr' being presumably RAM.

> Arbitariry redefining this meaning is counterproductive and confusing.
>
> If cmd_pxe.c uses incorrect names, then please fix the bug there.

I would say that 'fdt_addr' being the system provided DT, even when not
found on memory-mapped flash and 'fdt_addr_r' being the user provided
one is a logical extension.

If we want to set some new rules on these variables we're going to live
with for a long while and really document and enforce (see above about
fdt_addr/fdt_addr_r/fdtaddr current usage), OK, sure.

--
Tom
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