Re: [PATCH trivial] UAPI: Kbuild: add/modify comments for "uapi/Kbuild"and "uapi/linux/Kbuild"

[Chen Gang]

On 09/04/2013 05:02 PM, Geert Uytterhoeven wrote:
> On Wed, Sep 4, 2013 at 10:09 AM, Chen Gang <gang.chen@xxxxxxxxxxx> wrote:
>> On 09/04/2013 03:02 PM, Geert Uytterhoeven wrote:
>>> On Wed, Sep 4, 2013 at 3:08 AM, Chen Gang <gang.chen@xxxxxxxxxxx> wrote:
>>>> On 09/04/2013 12:41 AM, Geert Uytterhoeven wrote:
>>>>> On Tue, Aug 6, 2013 at 3:46 AM, Chen Gang <gang.chen@xxxxxxxxxxx> wrote:
>>>>>> --- a/include/uapi/Kbuild
>>>>>> +++ b/include/uapi/Kbuild
>>>>>> @@ -1,7 +1,6 @@
>>>>>>  # UAPI Header export list
>>>>>> -# Top-level Makefile calls into asm-$(ARCH)
>>>>>> -# List only non-arch directories below
>>>>>> -
>>>>>> +# Except "linux/", UAPI means Universal API.
>>>>>
>>>>> Sorry for my silly question, but what's the purpose of this "Universal
>>>>> API" comment?
>>>>>
>>>>
>>>> Firstly, at least for me, I don't think it is a silly question (maybe
>>>> it means I should give additional explanations).  :-)
>>>>
>>>> I 'guess' the "Universal API" means:
>>>>
>>>>   "the API which can be used under multiple OS (independent from Linux), it may be used under kernel mode or user mode".
>>>>
>>>> It is just my 'guess', welcome additional suggestions or completions by
>>>> any members.
>>>>
>>>> When we get this correct additional explanation after discussing, if
>>>> suitable, I should add the final explanation to current patch.
>>>
>>> Thanks. As this is not related at all to Linux, I don't see a reason
>>> to add this comment.
>>>
>>> Here, "UAPI" means "userspace API" only.
>>
>> Hmm... why we need "uapi/linux/" ?  (I can not find some related
>> documents, so I have to 'guess').
> 
> The "uapi" subdirectories are there to distinguish userspace headers from
> kernelspace headers, and allow both to live in the kernel source tree.
> 
> When running "make headers_install", the (processed) headers in the
> various "uapi" subdirectories are copied to /usr/include.
> Hence "uapi/linux/foo.h" becomes <linux/foo.h> in userspace.
> In userspace there are no "uapi" subdirectories anymore.
> 

Yeah, so why need another "uapi/*" excluding "uapi/linux" ?

Are they also truly still "Userspace API" but which need not distinguish
? (at least, it seems that idea is not quite good).

Hmm... maybe the "uapi/*" except "uapi/linux" are also installed? Is it
for compatible (originally they are here, and now we have to follow, it
is no reason to change if not find related critical issues)?


Thanks.

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
> 
> 


-- 
Chen Gang
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