[U-Boot] Breakage on gw_ventana

[Tim Harvey]

On Thu, May 19, 2016 at 6:02 AM, Stefano Babic <sbabic at denx.de> wrote:
> Hi Tim,
>
> last changes break build for the gw_ventana board. In fact, in case
> kernel is on a fs, we need to pass the name for kernel.  These two
> defines should be set into gw_ventana.h:
>
>         CONFIG_SPL_FS_LOAD_KERNEL_NAME
>         CONFIG_SPL_FS_LOAD_ARGS_NAME
>
> I could simply fix it, but it does not make sense without asking you :-)
>
> I have also seen that SPL for gw_ventana raises an exception because SPL
> is bigger as the value set into imx6_spl.h (CONFIG_SPL_MAX_SIZE = 64Kb).
> Anyway, CONFIG_SPL_MAX_SIZE for i.MX& iss too restrictive, and even the
> mx6 with smaller SRAM has at least 128KB.
>

Stefano,

Thanks for the heads-up. I have to admit I haven't looked at mainline
u-boot on Ventana for quite some time - I'm still using a 2015-04
branch with some patches on top that I haven't had time to mainline
yet.

When you say 'last changes' was there something specific? Something
must of grown the size of the SPL code quite a bit.

Your right that the smallest imx6 SRAM has 128KB although we have to
be careful not to clobber the SRAM being used by the boot ROM. The
reference manual indicates (IMX6*RM Figure 8-3) that there is only
free area 68KB available after you carve out the 28KB reserved
section, the 24KB MMU table, and the 8K stack. Admittedly I don't know
if the BOOT rom code really uses all of these areas in such a way that
it cant load the SPL into any of them. Take a look at my comments at
the top of include/configs/imx6_spl.h and let me know if you find
something wrong with my analysis that led to a 64KB max.

Regards,

Tim