[U-Boot-Users] Can U-boot Autodetect arch/ppcversusarch/powerpc from info in the uImage?
Joakim Tjernlund
joakim.tjernlund at transmode.se
Fri Dec 14 00:03:30 CET 2007
> -----Original Message-----
> From: Jerry Van Baren [mailto:gerald.vanbaren at ge.com]
> Sent: den 13 december 2007 19:49
> To: Wolfgang Denk
> Cc: joakim.tjernlund at transmode.se; u-boot-users at lists.sourceforge.net
> Subject: Re: [U-Boot-Users] Can U-boot Autodetect
> arch/ppcversusarch/powerpc from info in the uImage?
>
> Wolfgang Denk wrote:
> > In message
> <1197205927.937.51.camel at gentoo-jocke.transmode.se> you wrote:
> >> Made a new patch with Jerrys comments addressed. Also renamed
> >> DEFAULT_OF_TREE to CFG_OF_TREE. OK?
> >
> > I still object against this modification.
> >
> >> +#ifdef CFG_OF_TREE
> >> + char *of_flat_tree = CFG_OF_TREE;
> >> +#else
> >> char *of_flat_tree = NULL;
> >> +#endif
> >> ulong of_data = 0;
> >> #endif
> >
> > I hereby NAK this patch for 3 reasons:
> >
> > 1) The patch does not solve a problem. Instead of hardwiring the
> > address, you can just pass it as argument to the bootm command
> > which seems more straightforward to me
> >
> > 2) The patch causes confusion. Documented behaviour is that "bootm"
> > with one or two arguments (kernel address, or kernel plus ramdisk
> > addresses) will boot a non-OF enabled kernel. With this patch,
> > "bootm" will behave different on systems where the
> CFG_OF_TREE has
> > been selected - which is usually not known to and cannot be
> > checked by the end user, thus causing confusion.
> >
> > 3) With the patch applied and CFG_OF_TREE defined, there is
> no way to
> > boot a non-OF kernel, thus breaking backward compatibility.
> >
> > Best regards,
> >
> > Wolfgang Denk
>
> FWIIW, #2 and #3 are serious problems that I had not
> considered when I
> supported Jocke's proposed patch. Sorry, Jocke, but I have
> to side with
> Wolfgang in light of those arguments.
Right and I havn't been able to come up with a solution to that either.
So I am looking at passing a $dtb to bootm.
I noticed that I could define dtb i HUSH only by
dtb=0x12345678
Is it possible to do that from within board code too?
If so I don't have to worry about deleting $dtb when downgrading,
because it will never be saved in the env.
Jocke
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