[U-Boot] [PATCH v2 4/4] ARM: fix CONFIG_SPL_MAX_SIZE semantics

[Stephen Warren]

On 04/10/2013 04:50 PM, Albert ARIBAUD wrote:
> On Wed, 10 Apr 2013 16:21:54 -0600, Stephen Warren wrote:
>> On 04/09/2013 05:14 PM, Albert ARIBAUD wrote:
...
>> This still seems to have separate defines for SPL text/data/rodata size
>> and BSS size. If I want instead to limit the total text/data/rodata/bss
>> size, but place no specific limit on the bss size individually, can I
>> not do that?
> 
> This would defeat the purpose of giving CONFIG_SPL_MAX_SIZE a constant
> meaning -- one of the issues which prompted this patch series is that
> in ARM sometime CONFIG_SPL_MAX_SIZE meant BSS included, and sometime
> excluded, and this inconsistency had to be resolved. As in the rest of
> U-boot, CONFIG_SPL_MAX_SIZE was meant BSS excluded, this is the
> semantics that was decided.
> 
> What we could do, though, is subdivide testing based on the existence or
> non-existence of CONFIG_SPL_BSS_START_ADDR:
> 
> - if CONFIG_SPL_BSS_START_ADDR exists, then we assume SPL image and
>   BSS are disjoint and we test each one against its max size, as this
>   patch series does;
> 
> - if CONFIG_SPL_BSS_START_ADDR does not exist, then we assume SPL image
>   and BSS are contiguous and we test the whole of SPL against the sum
>   of CONFIG_SPL_MAX_SIZE and CONFIG_SPL_BSS_MAX_SIZE.

Why not either:

a) define CONFIG_SPL_MAX_SIZE to include the BSS size if
CONFIG_SPL_BSS_START_ADDR is not set, but exclude it if it is.

or:

b) use 3 defines instead of 2, so that CONFIG_SPL_MAX_SIZE (if defined)
always limits text+rodata+data, CONFIG_SPL_MAX_FOOTPRINT (if defined)
always limits text+rodata+data+bss, and CONFIG_SPL_BSS_MAX_SIZE (if
defined) always limits bss size.

Tegra would define only CONFIG_SPL_MAX_FOOTPRINT in this scheme. Other
boards would presumably define other combinations of those.