[PATCH 14/16] ARM: compile in image size and magic into barebox image
Marc Reilly
marc at cpdesign.com.au
Mon Apr 11 04:42:12 EDT 2011
Hi,
> > > @@ -38,6 +38,12 @@ void __naked __section(.text_entry)
> > > exception_vectors(void) "ldr pc, =not_used\n" /* (reserved) */
> > >
> > > "ldr pc, =irq\n" /* irq (interrupt) */
> > > "ldr pc, =fiq\n" /* fiq (fast interrupt) */
> > >
> > > + ".word 0x65726162\n" /* 'BARE' */
> > > + ".word 0x00786f62\n" /* 'BOX' */
>
> I just see that the comment is wrong. It's actually in lower case
> letters.
>
True.
(This is why I'm always reluctant to ack patches - I'm not very thorough :)
> > > + ".word _text\n" /* text base. If copied there,
> > > + * barebox can skip relocation
> > > + */
> > > + ".word _barebox_image_size\n" /* image size to copy */
> > >
> > > );
> > >
> > > }
> >
> > I like this, is there a way to include a version string/info also?
> >
> > (The aim is to be able to derive the barebox version of an image from
> > just reading the file).
>
> Should be possible. One problem might be that the length of the version
> string is variable, so if we put it here, it must be the piece of
> information here.
"it must be the _last_ piece of information here"?
Could also dedicate a fixed maximum size, although that's the kind of thing
that becomes a pain later.
>
> > > +extern void *_barebox_image_size;
> > > +
> > > +#define barebox_image_size (unsigned int)&_barebox_image_size
> >
> > I don't understand this line. Did you mean something like:
> >
> > #define barebox_image_size *((unsigned int *)_barebox_image_size)
> >
> > Or am I missing something?
>
> _barebox_image_size is filled in by the linker. It can be seen as a
> pointer which address corresponds to the image size. I know this looks
> strange and I don't really like this.
Ah, _now_ I get it. It looks strange but makes sense with your explanation
above, and I reckon that's OK.
> Maybe it can be done better?
Roberts suggestion to give it a comment is probably the best and simplest. The
alternate way I come up with isn't any better.
Cheers
Marc
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