Re: Building libm library

[Jeff Johnston <jjohnstn@redhat.com>]

On Thu, Jul 15, 2021 at 8:54 PM Harish <harishcse44@gmail.com> wrote:

> Ok, thanks for the clarification. One more question. I would like to use
> math library on a baremetal and want to know if the newlib math library
> uses system calls?. If yes, is there any other implementation which can be
> used for baremetals?
>
>
libm does not call system calls.  If you want to implement libc but don't
want to implement system calls, you can use libnosys which is a stub
library (e.g. reads fail, writes fail, etc...).
It is built as part of libgloss and you simply reference it using -lnosys
in your link.

Regards,
> Harish
>
> On Thu, 15 Jul, 2021, 11:19 pm Jeff Johnston, <jjohnstn@redhat.com> wrote:
>
>> Hello Harish,
>>
>> It isn't supported.  There are no top Makefile targets for you to do this
>> and building targets directly from Makefiles in subdirectories often
>> runs into issues (e.g. missing headers that haven't been copied or
>> paths/vars set incorrectly since they are supposed to be set by parent
>> Makefiles).
>> In addition, the errno/reentrant mechanisms used by libm.a are supplied
>> by libc.a.
>>
>> -- Jeff J.
>>
>> On Thu, Jul 15, 2021 at 7:44 AM Harish <harishcse44@gmail.com> wrote:
>>
>>> Hi newlib,
>>>
>>> I would like to build just libm.a library, is it possible? if yes, please
>>> let me know how can I do it.
>>>
>>>
>>> Thanks,
>>> Harish C
>>>
>>>