Unify multiple open-coded instances of integer binary logarithm.

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

Replace hard-coded bounce buffer uses in com32/lib with lmalloc/lfree.

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

Use libpci to access PCI config space.  This *hopefully* will make it
less likely that some old machine hangs when failing to set the
requested video mode.

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

If we specify a smaller image than the screen size, tile it across the
screen rather than leaving a big black box.  This may have to be made
configurable.

Also note that Syslinux currently does not handle the case of an image
bleeding off the end of the screen.

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

Add some code from the tool "915resolution" to allow arbitrary
resolutions to be set on some Intel chipsets.

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

Code formatting fix in screencpy.c

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

Unbreak the default background image; it would clobber all of memory.

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

Implement long-since-promised video functions defined in
<syslinux/video.h>.  Use these functions in initvesa.c instead of
open-coding the same functionality.

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

Don't display the cursor on the graphical screen while doing a quiet
boot.  When doing a quiet boot we will probably show the graphical
screen for a fair bit of time; as a result, we really don't want a
completely bogus cursor blob on the bottom of the screen.

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