N900 v3.19-rc5 arm atags_to_fdt.c is broken

[Pali Rohár]

On Monday 26 January 2015 17:14:55 Tony Lindgren wrote:
> * Pali Rohár <pali.rohar at gmail.com> [150123 14:39]:
> > On Friday 23 January 2015 22:39:55 Pali Rohár wrote:
> > > Hello,
> > > 
> > > when I boot zImage with appended DT n900 in qemu
> > > fdt_open_into() function called from file
> > > arch/arm/boot/compressed/atags_to_fdt.c (in function
> > > atags_to_fdt) always returns -FDT_ERR_NOSPACE.
> > > 
> > > It means that all ATAGS (including cmdline arguments)
> > > passed by bootloader are ignored.
> > > 
> > > On real n900 device I see that booted DT version also
> > > ignore cmdline arguments from bootloader. I cannot debug
> > > decompress code on real device, but I think it is same
> > > problem as in qemu.
> > 
> > Looks like this quick patch is fixing above problem:
> > 
> > diff --git a/arch/arm/boot/compressed/head.S
> > b/arch/arm/boot/compressed/head.S index 68be901..4a7d75b
> > 100644
> > --- a/arch/arm/boot/compressed/head.S
> > +++ b/arch/arm/boot/compressed/head.S
> > @@ -268,7 +268,7 @@ restart:	adr	r0, LC0
> > 
> >  		 * area.  No GOT fixup has occurred yet, but none of 
the
> >  		 * code we're about to call uses any global variable.
> >  		
> >  		*/
> > 
> > -		add	sp, sp, #0x10000
> > +		add	sp, sp, #0x20000
> > 
> >  		stmfd	sp!, {r0-r3, ip, lr}
> >  		mov	r0, r8
> >  		mov	r1, r6
> > 
> > @@ -289,7 +289,7 @@ restart:	adr	r0, LC0
> > 
> >  		bleq	atags_to_fdt
> >  		
> >  		ldmfd	sp!, {r0-r3, ip, lr}
> > 
> > -		sub	sp, sp, #0x10000
> > +		sub	sp, sp, #0x20000
> > 
> >  #endif
> >  
> >  		mov	r8, r6			@ use the appended device tree
> 
> Nico, got any ideas about this one? This seems like a
> regression somewhere..
> 
> Regards,
> 
> Tony

$ du -b arch/arm/boot/dts/omap3-n900.dtb 
70212   arch/arm/boot/dts/omap3-n900.dtb

$ echo $((0x10000))
65536

I would say, problem is because omap3-n900 binary DT is too large

-- 
Pali Rohár
pali.rohar at gmail.com
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