[U-Boot-Users] -nostdinc

[U-Boot-Users] -nostdinc

[Andrew Wozniak]

Hello,

Having lots of fun with U-boot on our custom PPC440GX board. We're also 
pretty far along on developing a loadable "u-boot application" for this 
board.

I've noticed that -nostdinc is used for many of the compiles. When I 
attempted to include stdlib.h and atoi() in our application, the 
compiler could not find the file.

Further examination of the U-Boot code-base shows little or no use of 
stdlib.h. Is this to keep the overall binary size to a minimum?

Any other reason for not adding this library to build? One simple 
alternative is to include our own atoi() source code.

Thanks and best regards, Andrew

[U-Boot-Users] -nostdinc

[Wolfgang Denk]

In message <422E60FD.50108@mc.com> you wrote:
> 
> Having lots of fun with U-boot on our custom PPC440GX board. We're also 
> pretty far along on developing a loadable "u-boot application" for this 
> board.

Congrats :-)

> I've noticed that -nostdinc is used for many of the compiles. When I 

It should be used for _all_ compiles of files that  get  linked  into
the U-Boot image. Please point out if we're missing any (of course it
is  NOT  used  for  any  tools that will run on the host system, like
mkimage etc.).

> attempted to include stdlib.h and atoi() in our application, the 
> compiler could not find the file.

That's a good thing as it prevented you to do a stupind thing ;-)

> Further examination of the U-Boot code-base shows little or no use of 
> stdlib.h. Is this to keep the overall binary size to a minimum?

It is to  make  U-Boot  self-contained,  i.  e.  independent  of  any
external libraries etc.

> Any other reason for not adding this library to build? One simple 

Yes. You don;t need it.

> alternative is to include our own atoi() source code.

Don't reinvent the wheel. Don't bloat the code by multiple  implemen-
tations of the same function. Use simple_strtoul() instead.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
About the use of language: it is impossible to sharpen a pencil  with
a  blunt  ax.  It is equally vain to try to do it with ten blunt axes
instead.                                           -- Edsger Dijkstra

[U-Boot-Users] -nostdinc

[Andrew Wozniak]

Thanks for the kind reply.

Wolfgang Denk wrote:
> In message <422E60FD.50108@mc.com> you wrote:
> 
>>Having lots of fun with U-boot on our custom PPC440GX board. We're also 
>>pretty far along on developing a loadable "u-boot application" for this 
>>board.
> 
> Congrats :-)
> 
>>I've noticed that -nostdinc is used for many of the compiles. When I 
> 
> It should be used for _all_ compiles of files that  get  linked  into
> the U-Boot image. Please point out if we're missing any (of course it
> is  NOT  used  for  any  tools that will run on the host system, like
> mkimage etc.).

I haven't seen any yet.

>>attempted to include stdlib.h and atoi() in our application, the 
>>compiler could not find the file.
> 
> That's a good thing as it prevented you to do a stupind thing ;-)
> 
>>Further examination of the U-Boot code-base shows little or no use of 
>>stdlib.h. Is this to keep the overall binary size to a minimum?
> 
> It is to  make  U-Boot  self-contained,  i.  e.  independent  of  any
> external libraries etc.

That's a good thing.

>>Any other reason for not adding this library to build? One simple 
> 
> Yes. You don;t need it.
> 
>>alternative is to include our own atoi() source code.
> 
> Don't reinvent the wheel. Don't bloat the code by multiple  implemen-
> tations of the same function. Use simple_strtoul() instead.

Ahhh, I was wondering how U-Boot handled this common task. I didn't look 
far enough.

> Best regards,
> 
> Wolfgang Denk
>