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

Add an option to update the in-memory version of FAT/NTFS hidden
sectors (== partition offset); load the boot sector for NTLDR.

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

Disable some debugging code that was never intended for production
use.  The intent is to track down specific memory-clobbering bugs.

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

The global absolute symbol STACK_TOP defined in layout.inc can be used
by the linker script as well as by anything else that needs to know
where the stack is.  Also document why we do it differently for
PXELINUX.

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

There is apparently some AMI BIOSes which leave a BEV stack just below
7c00h, which means that they can't return from the PXE NBP.  Thus, for
PXELINUX, move the stack down a few kilobytes.

This particularly refers to the "rouilj/ops12" system my private
sysdump archive.

Reported-and-tested-by: John Rouillard <rouilj@renesys.com>
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>

Null change to quiet a gcc warning.

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

Make "nopass" specific to the current drive type.  Add new option
"nopassany", which also clobbers the drive counts of both types.

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

Match the core with regards to the serial receive threshold.

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