[U-Boot] [PATCH 1/2] sunxi: Use Thumb2 and move stack to gain more SRAM space in FEL mode

Ian Campbell
2014-07-25T06:56:23Z

On Fri, 2014-07-25 at 04:01 +0300, Siarhei Siamashka wrote:
> On Mon, 21 Jul 2014 19:31:45 +0100
> Ian Campbell <ijc@hellion.org.uk> wrote:
>
> > On Fri, 2014-07-18 at 20:09 +0300, Siarhei Siamashka wrote:
> >
> > >
> > > http://lists.phcomp.co.uk/pipermail/arm-netbook/2012-June/004341.html
> >
> > I think a better reference is
> > https://github.com/hno/Allwinner-Info/blob/master/FEL-usb/USB-protocol.txt
>
> Yes, very likely. Except that I'm a little bit concerned about the
> long term availability of this link (which is a personal repository
> on github).
>
> I have quoted the relevant parts of the memory map information in the
> commit message. But now I wonder if we should replicate the Allwinner
> FEL mode memory map information somewhere in the u-boot documentation?

Or move it to the sunxi wiki?

> > [...]
> > > + /* Pass control to the 's_init()' function */
> > > + b s_init
> >
> > Since this code is in arm mode and s_init will, I think, be in Thumb
> > mode after this patch shouldn't this be a bx?
>
> Since this branch instruction refers to an external symbol, the linker
> has all the necessary information and takes care of handling Thumb
> interworking whenever it is necessary.

OK.