[ELDK] Discrepancy in Denx PowerPC termios.h header

Wolfgang Denk wd at denx.de
Sat Aug 15 00:34:17 CEST 2009

Dear Ryan,

in message <C602DB4CB80BF54194816250C56A2C11024060CC at ausx3mpc112.aus.amer.dell.com> you wrote:
> The {ELDK_ROOT}/ppc_4xx/usr/include/bits/termios.h includes
>   #define NCCS 32

ELDK is based on the Fedora distribution, so we inherit what Fedora is
doing. Let's see:

Fedora 10 on i686:

-> uname -a
Linux gemini.denx.de #1 SMP Fri Jul 31 04:40:15 EDT 2009 i686 i686 i386 GNU/Linux
-> grep 'define NCCS' /usr/include/bits/termios.h
#define NCCS 32

Fedora 10 on ppc64:

-> uname -a
Linux titan.denx.de #1 SMP Sun Jun 21 18:32:32 EDT 2009 ppc64 ppc64 ppc64 GNU/Linux
-> grep 'define NCCS' /usr/include/bits/termios.h
#define NCCS 32

As you can see, the ELDK is at least consistent with what  Fedora  is

> But in recent and old 2.6 kernels NCCS is defined as 19. 

Ummm... that's in arch/*/include/asm/termbits.h, not in
arch/*/include/asm/termios.h, and the value is not always 19, but
also 17 (sparc) or 23 (mips).

> In addition, the c_line variable within the termios structure is located
> below the c_cc[NCCS] variable within the kernel, but not in this glibc
> header file.
> It seems like the private glibc header file (bits/termios) is for a
> completely different architecture. This came up with us trying to track
> down a bug in our Busybox stty.c which was doing a memcmp on old and new
> termios settings and failing.

Is this the Busybox as included with the ELDK, or something you built

> Any explanation or help would be appreciated.

Fedora's bugzilla seems to know nothing about such a problem.
It might be useful to file a bug report there.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"There was no difference between  the  behavior  of  a  god  and  the
operations of pure chance..."   - Thomas Pynchon, _Gravity's Rainbow_

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