[U-Boot] [PATCH] arm: omap5: am57/dra7: Fix SRAM_SCRATCH_SPACE_ADDR and SRAM_ROM_VECT_BASE

[Tom Rini]

On Fri, Aug 05, 2016 at 12:14:23PM -0400, Andrew Bradford wrote:

> From: Andrew Bradford <andrew.bradford at kodakalaris.com>
> 
> Both am57xx and dra7xx have 512 kiB of SRAM and the mapping within that
> SRAM is the same as omap5 (which has only 128 kiB) except for a much
> larger "Download image" area.  So, fix am57xx and dra7xx location for
> SRAM_SCRATCH_SPACE_ADDR to mimmic omap5's locating of this area to a
> memory region defined by the TRM as "Reserved" immediately following the
> "Download image" region and fix the ROM code interrupt vector address
> SRAM_ROM_VECT_BASE to properly match the TRM.
> 
> Signed-off-by: Andrew Bradford <andrew.bradford at kodakalaris.com>
> ---
>  arch/arm/include/asm/arch-omap5/omap.h | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm/include/asm/arch-omap5/omap.h b/arch/arm/include/asm/arch-omap5/omap.h
> index 2fd5cda..b9e4783 100644
> --- a/arch/arm/include/asm/arch-omap5/omap.h
> +++ b/arch/arm/include/asm/arch-omap5/omap.h
> @@ -179,21 +179,19 @@ struct s32ktimer {
>   * and indicates the area for the downloaded image.  We use all of that
>   * space for download and once up and running may use other parts of the
>   * map for our needs.  We set a scratch space that is at the end of the
> - * OMAP5 download area, but within the DRA7xx download area (as it is
> - * much larger) and do not, at this time, make use of the additional
> - * space.
> + * download area in an area marked reserved in the TRM.
>   */
>  #if defined(CONFIG_DRA7XX) || defined(CONFIG_AM57XX)
>  #define NON_SECURE_SRAM_START	0x40300000
>  #define NON_SECURE_SRAM_END	0x40380000	/* Not inclusive */
> +#define SRAM_SCRATCH_SPACE_ADDR	0x4037E000
> +#define SRAM_ROM_VECT_BASE	0x4037F000
>  #else
>  #define NON_SECURE_SRAM_START	0x40300000
>  #define NON_SECURE_SRAM_END	0x40320000	/* Not inclusive */
> -#endif
>  #define SRAM_SCRATCH_SPACE_ADDR	0x4031E000
> -
> -/* base address for indirect vectors (internal boot mode) */
>  #define SRAM_ROM_VECT_BASE	0x4031F000
> +#endif

So, this is totally following existing examples.  But on further review,
I don't like the existing examples, which, hey, is my fault, I wrote
them.  I don't like that mostly we put the scratch space into a
"reserved" area (which may or may not trample ROM and that could be bad
in some corner cases). Looking things over, we claim we need a maximum
of 0x228 bytes of scratch space and we currently use more like 0x8a
bytes of it.  However, depending on the platform we are on, we may claim
between 8 and 32 KiB for all of this.  And stack in SPL is elsewhere in
these defines and not a worry.  I'm build testing a patch now and will
boot test it on a good subset of the hardware before posting that should
address all of this.  Thanks for bringing it up!

-- 
Tom
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