Re: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly

Re: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly

[Ralf Baechle]

On Fri, Aug 15, 2014 at 12:54:53AM +0800, Chen Gang wrote:

> Normal architectures:
> 
>  - Big endian: avr32, frv, m68k, openrisc, parisc, s390, sparc
> 
>  - Little endian: alpha, blackfin, cris, hexagon, ia64, metag, mn10300,
>                   score, unicore32, x86
> 
>  - Choose in config time: arc, arm, arm64, c6x, m32r, mips, powerpc, sh

Nak for MIPS.  On MIPS Kconfig already always sets one of CPU_BIG_ENDIAN
and CPU_LITTLE_ENDIAN depending on platforms and where both endianess are
supported by a platform, user choice:

config FOO
	bool "foo"
	select SYS_SUPPORTS_LITTLE_ENDIAN

config FOO
	bool "foo"
	select SYS_SUPPORTS_BIG_ENDIAN
	select SYS_SUPPORTS_LITTLE_ENDIAN
[...]
choice
        prompt "Endianess selection"
        help
          Some MIPS machines can be configured for either little or big endian
          byte order. These modes require different kernels and a different
          Linux distribution.  In general there is one preferred byteorder for a
          particular system but some systems are just as commonly used in the
          one or the other endianness.

config CPU_BIG_ENDIAN
        bool "Big endian"
        depends on SYS_SUPPORTS_BIG_ENDIAN

config CPU_LITTLE_ENDIAN
        bool "Little endian"
        depends on SYS_SUPPORTS_LITTLE_ENDIAN
        help

endchoice

So I think you can just drop the MIPS segment from your patch.

  Ralf

Re: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly

[Chen Gang]

On 08/15/2014 02:04 AM, Ralf Baechle wrote:
> On Fri, Aug 15, 2014 at 12:54:53AM +0800, Chen Gang wrote:
> 
>> Normal architectures:
>>
>>  - Big endian: avr32, frv, m68k, openrisc, parisc, s390, sparc
>>
>>  - Little endian: alpha, blackfin, cris, hexagon, ia64, metag, mn10300,
>>                   score, unicore32, x86
>>
>>  - Choose in config time: arc, arm, arm64, c6x, m32r, mips, powerpc, sh
> 
> Nak for MIPS.  On MIPS Kconfig already always sets one of CPU_BIG_ENDIAN
> and CPU_LITTLE_ENDIAN depending on platforms and where both endianess are
> supported by a platform, user choice:
> 
> config FOO
> 	bool "foo"
> 	select SYS_SUPPORTS_LITTLE_ENDIAN
> 
> config FOO
> 	bool "foo"
> 	select SYS_SUPPORTS_BIG_ENDIAN
> 	select SYS_SUPPORTS_LITTLE_ENDIAN
> [...]
> choice
>         prompt "Endianess selection"
>         help
>           Some MIPS machines can be configured for either little or big endian
>           byte order. These modes require different kernels and a different
>           Linux distribution.  In general there is one preferred byteorder for a
>           particular system but some systems are just as commonly used in the
>           one or the other endianness.
> 
> config CPU_BIG_ENDIAN
>         bool "Big endian"
>         depends on SYS_SUPPORTS_BIG_ENDIAN
> 
> config CPU_LITTLE_ENDIAN
>         bool "Little endian"
>         depends on SYS_SUPPORTS_LITTLE_ENDIAN
>         help
> 
> endchoice
> 

OK, thanks, I assumes when support both endian, the default choice is
CPU_BIG_ENDIAN, although no default value for choice (originally, I did
worry about it).

> So I think you can just drop the MIPS segment from your patch.
> 

If what I assumes is correct, what you said sounds reasonable to me.


Thanks.
-- 
Chen Gang

Open share and attitude like air water and life which God blessed

Re: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly

[Chen Gang]

On 8/15/14 6:14, Chen Gang wrote:
> On 08/15/2014 02:04 AM, Ralf Baechle wrote:
>>
> 
> OK, thanks, I assumes when support both endian, the default choice is
> CPU_BIG_ENDIAN, although no default value for choice (originally, I did
> worry about it).
> 
>> So I think you can just drop the MIPS segment from your patch.
>>
> 
> If what I assumes is correct, what you said sounds reasonable to me.
> 
> 

So for me, it is harmless to add CPU_*_ENDIAN explicitly, and can let
other members don't need think of.

By the way, for sh, it is almost the same case, except it contents the
default value, for me, it is clear enough, so I skip sh architecture in
this patch.


Thanks
-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed

Re: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly

[Chen Gang]

Hello Maintainers:

Is this patch OK? If it pass basic checking, please let me know, and I
shall try to make another related patch for KBuild (I can do nothing
related with Kbuild, before get confirmation for this patch).

Thanks.

On 8/15/14 17:01, Chen Gang wrote:
> 
> 
> On 8/15/14 6:14, Chen Gang wrote:
>> On 08/15/2014 02:04 AM, Ralf Baechle wrote:
>>>
>>
>> OK, thanks, I assumes when support both endian, the default choice is
>> CPU_BIG_ENDIAN, although no default value for choice (originally, I did
>> worry about it).
>>
>>> So I think you can just drop the MIPS segment from your patch.
>>>
>>
>> If what I assumes is correct, what you said sounds reasonable to me.
>>
>>
> 
> So for me, it is harmless to add CPU_*_ENDIAN explicitly, and can let
> other members don't need think of.
> 
> By the way, for sh, it is almost the same case, except it contents the
> default value, for me, it is clear enough, so I skip sh architecture in
> this patch.
> 
> 
> Thanks
> 

-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed

Re: [PATCH v3] arch: Kconfig: Let all architectures set endian explicitly

[Chen Gang]

Hello all:

It seems no any additional rejections for it. I guess, I need split the
'big' patch into pieces, and each send to its' related mailing list, so
let it not like a spam. And the schedule may like:

 - Firstly, send patch for "init/Kconfig" to add CPU_*_ENDIAN. If pass
   checking (hope it can be passed checking), then

 - Send each related patch to each related architectures which already
   knew their ENDIAN attributes in config time (24 patches, I guess),
   then

 - Make patch for Kbuild to support __BUILDING_TIME_BIG_ENDIAN__, and
   pass checking (hope I can finish), then

 - Finish left architectures which need __BUILDING_TIME_BIG_ENDIAN__
   (4 patches, I guess).

Welcome any ideas, suggestions, or completions. And if no additional
reply, I shall not send any additional information any more to avoid
spam to other members.


Thanks.

On 08/24/2014 04:38 PM, Chen Gang wrote:
> Hello Maintainers:
> 
> Is this patch OK? If it pass basic checking, please let me know, and I
> shall try to make another related patch for KBuild (I can do nothing
> related with Kbuild, before get confirmation for this patch).
> 
> Thanks.
> 
> On 8/15/14 17:01, Chen Gang wrote:
>>
>>
>> On 8/15/14 6:14, Chen Gang wrote:
>>> On 08/15/2014 02:04 AM, Ralf Baechle wrote:
>>>>
>>>
>>> OK, thanks, I assumes when support both endian, the default choice is
>>> CPU_BIG_ENDIAN, although no default value for choice (originally, I did
>>> worry about it).
>>>
>>>> So I think you can just drop the MIPS segment from your patch.
>>>>
>>>
>>> If what I assumes is correct, what you said sounds reasonable to me.
>>>
>>>
>>
>> So for me, it is harmless to add CPU_*_ENDIAN explicitly, and can let
>> other members don't need think of.
>>
>> By the way, for sh, it is almost the same case, except it contents the
>> default value, for me, it is clear enough, so I skip sh architecture in
>> this patch.
>>
>>
>> Thanks
>>
> 

-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed