[PATCH v2] tests: Build correct sandbox configuration on 32bit

[Heinrich Schuchardt]

On 10/15/22 20:39, Simon Glass wrote:
> Hi Heinrich,
>
> On Sat, 15 Oct 2022 at 12:31, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>>
>> On 10/15/22 19:53, Simon Glass wrote:
>>> Hi Michal,
>>>
>>> On Fri, 14 Oct 2022 at 14:53, Michal Suchanek <msuchanek at suse.de> wrote:
>>>>
>>>> Currently sandbox configuration defautls to 64bit and there is no
>>>> automation for building 32bit sandbox on 32bit hosts.
>>>>
>>>> Use _LP64 macro as heuristic for detecting 64bit targets.
>>>>
>>>> Signed-off-by: Michal Suchanek <msuchanek at suse.de>
>>>> ---
>>>>
>>>> Changes in v2:
>>>> simplify and move detection to kconfig
>>>>
>>>> ---
>>>>    arch/sandbox/Kconfig    | 18 +++---------------
>>>>    scripts/Kconfig.include |  4 ++++
>>>>    2 files changed, 7 insertions(+), 15 deletions(-)
>>>
>>> Reviewed-by: Simon Glass <sjg at chromium.org>
>>>
>>> My only question is whether we can allow building the 32-bit version
>>> on a 64-bit machine? That would need a separate option I think, to
>>> say:
>>>
>>> I don't want you to automatically determine HOST_32/64BIT. Instead,
>>> use 32 (or 64).
>>>
>>> This is along the lines of what Heinrich is saying, except that I
>>> strongly feel that we must do the right thing by default, as your
>>> patch does.
>>
>> The whole point of phys_addr_t and phys_size_t is that it can be 64bit
>> or 32bit on ilp32.
>>
>> With this patch we cannot build with CONFIG_PHYS_64BIT=y on ilp32 and
>> that is bad.
>>
>> 32 bit phys_addr_t on lp64 is irrelevant for actual hardware but this is
>> what we currently test with sandbox_defconfig on Gitlab CI.
>>
>> My patch is ending up in the same behavior as Michal's patch except that
>> it allows to have 64bit phys_addr_t on ilp32.
>
> It needs to automatically default to 32 or 64 bit depending on the
> host. If the user wants to fiddle with Kconfig to force it to the
> other one, that should be possible to.
>
> It looks like your patch requires manual configuration, but perhaps I
> just misunderstood it?

__LP64__ is a symbol defined by the compiler when compiling for 64bit
and not defined when compiling for 32bit systems. There is nothing
manual about it.

My patch uses this symbol to replace HOST_32BIT and HOST_64BIT.

Michal's patch compiles a program tools/bits-per-long.c that ends up
returning 64 on 64 bit systems (where __LP64__ is defined) and 32 on 32
bit systems (where __LP64__ is not defined) and then chooses HOST_32BIT
and HOST_64BIT accordingly. This part of Michal's patch is not wrong.
The solution is only overly complicated.

What has to be chosen manually with both patches is PHYS_64BIT e.g. by
selecting sandbox64_defconfig instead of sandbox_defconfig.

Unfortunately Michal did not understand that PHYS_64BIT=y, HOST_32BIT=y
is a necessary test scenario and introduced an invalid dependency.

With my patch sandbox64_defconfig on a 32bit system uses 64bit phys_addr_t.

With Michal's patch sandbox64_defconfig on a 32bit system uses 32bit
phys_addr_t.

Best regards

Heinrich