[syslinux] where to swap

[Martin Str|mberg]

On Sat, Mar 25, 2017 at 09:28:16PM +0100, Thomas Schmitt via Syslinux wrote:
> I think it still has good reason to exist. The test
> 
> 	cmpw	$0xaa55, %bx
> 	jne	1f
> 
> could cause a jump which could push a non-zero CX to the stack.

Yes. But that can be fixed by putting the "andw $1, %cx" test before
the "cmpw $0xaa55, %bx" test.

But then if CX is filled with rubbish and carry is set (the first
test) could lead to 0 != CX... I have no idea if this can happen.

As you say, as is is the most safe.


-- 
MartinS