[U-Boot] [PATCH 11/17] OMAP5: defconfig: Align the defconfig for 5430 ES1.0

[Tom Rini]

On Tue, Feb 21, 2012 at 01:16:58PM +0530, R, Sricharan wrote:
> Hi Tom,
> 
> On Mon, Feb 20, 2012 at 11:15 PM, Tom Rini <trini at ti.com> wrote:
> 
> > On Fri, Feb 17, 2012 at 05:35:27PM +0530, R Sricharan wrote:
> >
> > > Adding the nessecary changes for OMAP5430 ES1.0 silicon.
> > >
> > > Signed-off-by: R Sricharan <r.sricharan at ti.com>
> > [snip]
> > > +/* OPP SETTING */
> > > +#define OPP_NOM
> >
> > Where is this used?
> > Right. This is unused. Will remove this. We were having
> >
>    OPP_LOW and OPP_HIGH settings in the clocks table, for internal testing.
>    But that being eventually removed, this is not required.
> 
> 
> > [snip]
> > >  /* Defines for SPL */
> > >  #define CONFIG_SPL
> > > -#define CONFIG_SPL_TEXT_BASE         0x40304350
> > > -#define CONFIG_SPL_MAX_SIZE          0x1E000 /* 120K */
> > > +#define CONFIG_SPL_TEXT_BASE         0x40300350
> > > +#define CONFIG_SPL_MAX_SIZE          0x20000 /* 128K */
> > >  #define CONFIG_SPL_STACK             LOW_LEVEL_SRAM_STACK
> >
> > This is wrong, you have to account for stack within SPL_MAX_SIZE.
> >
> >     To understand,
>     So now, LOW_LEVEL_SRAM_STACK points to SRAM base + 128KB address (which
> is the SRAM size),
>     pointed to by NON_SECURE_SRAM_END
>    Should this be changed ?
>    Also CONFIG_SYS_INIT_SP_ADDR should be adjusted. Will change this

So, the issue (see http://patchwork.ozlabs.org/patch/142211/ as I
believe omap4/5 are similar in method) is that both SPL text/data/rodata
and stack reside in SRAM.  So we use CONFIG_SPL_MAX_SIZE as a way of
ensuring that at least some portion of SRAM will be available for
stack).  You need to pick how much will be available for each part.  For
example, on am335x we also have 128KB of SRAM but do an arbitrary split
at 46KB for SPL (since we haven't needed more than that).  All you need
to do is pick SPL_MAX_SIZE less than 128KB.  And prepare to write a
README.omap45 or so similar to the README.omap3 I wrote :)

-- 
Tom