Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Mark global functions and/or variables in fdread(8) static where possible.

This allows compilers and static analyzers to do more thorough analysis.

Open the floppy disk device with O_RDONLY rather than O_RDWR. After
all, this is the fd*read* command, and thus should be able to read
even write-protected disks.

MFC after: 1 week

Drop the defunct FDOPT_NOERRLOG option from all the floppy utilities.
The kernel does not log floppy media errors anymore.

In fdcontrol, do always open the file descriptor in read-only mode so
it can operate on read-only media, as there is no longer a separate
control device to operate on.

Remove unused variables.

fdread cannot work without opening the /dev/fd node in O_RDWR mode now,
because it sets the floppy controller parameters, which requires O_RDWR.
Specifically, the FD_SOPTS ioctl requires this, and the code errors out
and aborts if it can't do it. Among other things, it is changing the
FDOPT_NOERRLOG flag. Broken in 6.0 as well.

Cleanup usr.sbin/fd* so they can compile under WARNS=6.

fdcontrol/fdcontrol.c:
- Add const constraint to an intermediate value
which is not supposed to be changed elsewhere.
fdread/fdread.c:
- Use _devname in favor of devname to avoid name
conflicit.
- -1 is less than any positive number so in order
to get the block to function, we should get the
block a little earlier.
- Cast to remove signed when we are sure that a
return value is positive, or is compared with
an positive number (tracknumber of a floppy
disk is not likely to have UINT_MAX/2 anyway)
fdread/fdutil.c:
- Use more specific initializer
fdwrite/fdwrite.c:
- Use static on format_track since it's not
referenced in other places.
- Use const char* to represent string constant.

Bump WARNS accordingly.

Break out the function to print the FDC error information into
fdutil.c so it can be used elsewhere.

Implement the -I option that uses the FD_READID ioctl in order to read
sector ID fields from a floppy, and display them.

Part #2 of the <machine/ioctl_fd.h> => <sys/fdcio.h> move: handle the
tools in usr.sbin/fd*.

Now that we've got the ne765.h file installed under <dev/ic/>, use it
here instead of the old "/sys/isa/ic/..." hack. This should fix
building the world for machines that don't have a /sys symlink,
finally.

This commit was generated by cvs2svn to compensate for changes in r76589,
which included commits to RCS files with non-trunk default branches.

Initial import of fdread(1), a logical counterpart to fdwrite(1).

Its main purpose is to adapt automatically to the floppy parameters
(in particular the track size for efficient reading), and to allow a
simple error recovery for CRC-errored sectors. Requires the newly
added fdc(4) options.