[PATCH 4/5] [ARM] Auto calculate ZRELADDR and provide option for exceptions

[Uwe Kleine-König]

Hello,

On Thu, Sep 02, 2010 at 10:27:23PM +0100, Russell King - ARM Linux wrote:
> On Thu, Sep 02, 2010 at 10:21:45PM +0100, Russell King - ARM Linux wrote:
> > On Thu, Jun 03, 2010 at 03:36:52PM +0800, Eric Miao wrote:
> > > From: Eric Miao <eric.y.miao at gmail.com>
> > > 
> > > Original idea and prototype came from Nicolas Pitre.
> > > 
> > > As long as the zImage is placed within the 256MB range from the
> > > start of the memory, ZRELADDR (Address where the decompressed
> > > kernel will be placed, usually  == PHYS_OFFSET + TEXT_OFFSET)
> > > can be determined at run-time by masking PC with 0xf000_0000.
> > > 
> > > Running through all the Makefile.boot, all those zreladdr-y
> > > address == 0x[0-f]000_0000 + TEXT_OFFSET can be determined at
> > > run-time.
> > > 
> > > Option CONFIG_AUTO_ZRELADDR and CONFIG_ZRELADDR are introduced,
> > > CONFIG_ZRELADDR _must_ be explicitly specified if:
> > > 
> > >  - ((zreladdr-y - TEXT_OFFSET) & ~0xf0000000) != 0, which means
> > >    a maksing of PC with 0xf000_0000 will result an incorrect
> > >    address.
> > > 
> > >  - or the assumption of the zImage being loaded by the boot
> > >    loader within 256MB from the start address is simply
> > >    incorrect
> > > 
> > >  - or when ZBOOT_ROM is used, where the above assumption is
> > >    normally wrong
> > > 
> > > List of all Makefile.boot:
> > 
> > Not so.  What happened to H720x platforms, which are now broken?
> > Any chance of fixing the regression that this introduced?
> > 
> > http://armlinux.simtec.co.uk/kautobuild/2.6.36-rc3/h7202_defconfig/zimage.log
> 
> And while we're here, why hasn't anyone removed the zreladdr
> definitions in Makefile.boot yet?  Or do we still need them and
> we now have the same information defined in two different places?
> 
> This all looks like a half-done job at the moment.  Please clean it up.
The original series removed all the 'Makefile.boot's IIRC.  Currently
the params_phys-y value is needed though.  So should I send a patch that
just removes the zreladdr values?

Eric, what are your plans regarding the runtime-physoffset stuff?  (I
currently have none.)

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |