[PATCH] Makefile: doesn't need check stack size when dtb is not built

[Stephen Warren]

On 3/4/20 5:15 PM, AKASHI Takahiro wrote:
> On Wed, Mar 04, 2020 at 09:21:29AM -0700, Stephen Warren wrote:
>> On 3/3/20 11:54 PM, AKASHI Takahiro wrote:
>>> The commit 5fed97af20da ("Makefile: ensure DTB doesn't overflow into
>>> initial stack") adds an extra check for stack size in BSS if
>>> CONFIG_SYS_INIT_SP_BSS_OFFSET is enabled.
>>> This check, however, doesn't make sense under the configuration where
>>> control dtb won't be built in and it should be void in such cases.
>>
>> Don't you want to edit the following hunk from the original patch instead or
>> as well?
>>
>> +ifneq ($(CONFIG_SYS_INIT_SP_BSS_OFFSET),)
>> +ALL-y += init_sp_bss_offset_check
>> +endif
>>
>> That's why there's no rule for init_sp_bss_offset_check in the else case.
> 
> I intentionally left it as it is because someone may in the future
> want to add other *sanity checks* whether dtb is used or not.

I'd probably expect the following in that case:

ifneq ($(CONFIG_SYS_INIT_SP_BSS_OFFSET),)
   ifneq ($(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_OF_HOSTFILE),)
     ALL-y += init_sp_bss_offset_check
   endif
   ALL-y += some_other_check
endif

> Rather, my concern is:
> Is "ifneq ($(CONFIG_OF_SEPARATE)$(CONFIG_OF_EMBED)$(CONFIG_OF_HOSTFILE),)"
> sufficient and appropriate to guard the check?

I think OF_SEPARATE is the only case this check makes sense. OF_EMBED 
sounds like the build process puts the DTB into .data or similar, so the 
issue doesn't apply. Since OF_HOSTFILE is a sandbox thing where the DT 
is read from a file, the check definitely doesn't apply.