Re: Trouble compiling GRUB

[Farid Hajji]

> > What's going on? I was able to compile an earlier version of grub
> > (grub-0.5.96 from CVS) without problems.
> 
>   Perhaps that is due to a bug in your gcc. In gcc-2.7.x, the option
> "-B" (and also "-v") worked just fine, but gcc-2.95.x seems not to
> work. A workaround could be to install gcc as well as binutils into a
> private directory. *sigh*
Hmmm... I doubt that this is the case. I compiled grub-0.5.96 with
gcc-2.95.2 (and -B -> binutils-2.10) and that worked fine.

Trying gcc27 (gcc-2.7.2.3) instead of gcc-2.95.2 returned the same error
message about 'too many input files'.
  CC=gcc27 ./configure --with-binutils=/usr/local/bin

> > # O_SYNC in grub/asmstub.c not recognized on my system.
> > # removed O_SYNC flag in line 1032 of grub/asmstub.c.
> > # this worked with grub 0.5.96
> 
>   Please report any bug! I haven't ever heard this. Doesn't FreeBSD
> support O_SYNC? I thought it should have, because O_SYNC is defined in
> POSIX. In FreeBSD, how to ensure that I/O operations are synchronous?
O_SYNC is not defined in FreeBSD. Use O_FSYNC instead.

from /usr/include/fcntl.h:

#ifndef _POSIX_SOURCE
#define FREAD           0x0001
#define FWRITE          0x0002
#endif
#define O_NONBLOCK      0x0004          /* no delay */
#define O_APPEND        0x0008          /* set append mode */
#ifndef _POSIX_SOURCE
#define O_SHLOCK        0x0010          /* open with shared file lock */
#define O_EXLOCK        0x0020          /* open with exclusive file lock */
#define O_ASYNC         0x0040          /* signal pgrp when data ready */
#define O_FSYNC         0x0080          /* synchronous writes */
#define O_NOFOLLOW      0x0100          /* don't follow symlinks */
#endif
#define O_CREAT         0x0200          /* create if nonexistent */
#define O_TRUNC         0x0400          /* truncate to zero length */
#define O_EXCL          0x0800          /* error if already exists */
#ifdef _KERNEL
#define FMARK           0x1000          /* mark during gc() */
#define FDEFER          0x2000          /* defer for next gc pass */
#define FHASLOCK        0x4000          /* descriptor holds advisory lock */
#endif

Beware that O_FSYNC is not defined if _POSIX_SOURCE is defined!

I've just checked that open() with O_FSYNC really syncs every write()
to disk. If O_FSYNC is omitted, no immediate synchronization is performed
(as expected).

> Thanks,
> Okuji

-Farid.

-- 
Farid Hajji -- Unix Systems and Network Admin | Phone: +49-2131-67-555
Broicherdorfstr. 83, D-41564 Kaarst, Germany  | address@hidden
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