Previous commits described this behaviour, but did not
actually implement it. :)

Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>

In order to consolidate the installer option-parsing system,
we add the --mbr (-m), --active (-a), and --force (-f)
options from the DOS, Win32, and mtools installers to
libinstaller.

Since the -m and -a options are not currently valid for the
Linux 'syslinux' and 'extlinux' installers, we add error
messages to both of these.  The -f option is allowed but
does nothing for them.

Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>

It appears that the glibc version of asprintf() is braindamaged, and
doesn't set the target pointer to NULL in the event of an error (only
returns -1).  Therefore we need to check the return value.  Just in
case someone else made the *opposite* error, also check the pointer.

Bleh.  The glibc documentation states that *BSD sets the pointer to
NULL, but instead of following that, the glibc people put
warn_unused_result on asprintf.  Sigh.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

modify_adv() should be used by any installer which uses the common
CLI, so it should go into syslxopt.c.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Install an empty ADV in the Windows installer to keep it from being
broken.  In order to do that, separate the Unix-specific ADV I/O
functions from the generic data structure manipulation.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Our linux distribution at my job didn't include a /tmp directory. When ever
I tried to use syslinux, I would get the following error:

./syslinux: No such file or directory

I modified the code to report this:

./syslinux: Cannot access the /tmp/ directory.

This would have helped me a lot rather than having to download the source
and run it through the debugger to figure out that my /tmp/ directory was
missing. I suspect if this ever happens again I'll know exactly what was
wrong, but hopefully it will help someone else.

Merge the SYSLINUX and EXTLINUX patching code and core code, removing
EXTLINUX as a separate derivative.  All the disk-based systems now use
the same code.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Fix mishandling of the null pathname case in the syslinux installer,
and generally clean up the handling of the subpath name.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Put all the Linux ioctl header magic into a single shared file, and
try to make it as generally useful as possible.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Switch to consistent use of 64-bit sector pointers; this should enable
booting even for individual *partitions* larger than 2 TB.  In order
to not slow down the boot too much, switch the initial load from an
enumeration to an extent map.  This means the table gets larger (since
we have to assume the worst case), but it simplifies the Sector 1 code
(since we can push all the hard stuff into the installer), and will
speed up booting in the general case.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>