Re: [PATCH] omap: use 512k barebox partition

[Sascha Hauer <s.hauer@pengutronix.de>]

On Mon, Jul 30, 2012 at 10:11:32AM +0200, Juergen Beisert wrote:
> Hi Sascha,
> 
> Sascha Hauer wrote:
> > On Fri, Jul 27, 2012 at 06:54:16PM +0200, Juergen Beisert wrote:
> > > Sascha Hauer wrote:
> > > > On Fri, Jul 27, 2012 at 01:09:07PM +0200, Jan Weitzel wrote:
> > > > > Use 512k NAND Partion for barebox. Problem is we don't know the size
> > > > > of the barebox inside xload. Set it also to 512k
> > > > > Fix enviroment for boards with size in config
> > > >
> > > > The barebox binary has the size encoded into it at offset 0x2c. We
> > > > could use this to transfer the correct size.
> > >
> > > Will this be a reliable "API" to the outerworld? Also in future versions
> > > of Barebox?
> >
> > Yes, definitely.
> >
> > That said, it is not a feature you can generally rely upon, because some
> > SoCs may require some special image layout conflicting with this.
> 
> This would require a "movable marker" inside the binary image.
> 
> > If your SoC can support this header, barebox will support it in the future
> > aswell.
> 
> Okay.
> 
> > The header is in arch/arm/include/asm/barebox-arm-head.h. As you can see
> > it also contains the ascii string 'barebox' which means that you can
> > test for it, and if you find it, the next word will contain the address
> > this binary should be copied to (only used to skip copying the binary to
> > the correct place, it's not mandatory to start the image there). The
> > word after it will contain the image size.
> >
> > This means, what you can do is:
> >
> > - Test if the image contains 'barebox'
> 
> This might be very dangerous, as this kind of string can be part of the binary 
> more than one times, if it is used as part of an output string for example 
> ("Hi, barebox here").

Should have said: 'contains the string 'barebox' at offset 0x20'

Sascha


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