[syslinux] a problem with pxelinux

[H. Peter Anvin]

Harish Zunjarrao wrote:
>> 
> In my int 1Ah code, i.e. in my ISR initially I have pushed all the flags
> then provided PXENV+ structure pointer 
> 
> and then popped all the flags before returning from the ISR
> 
> Thus I am not changing any flags.
> 

[...]

> 
> If I clear the carry flag in my ISR, my keyboard gets hung.
> 

You should only change the flags if it's talking to *you*!

You need to clear at least the carry flag (I suggest simply zeroing out 
the bottom byte of the flags word on the stack), but you can only do 
this after you have decoded the invocation and decided that it's 
addressed to you.

	-hpa