[syslinux] Read disk not working in 3.35+

[H. Peter Anvin]

H. Peter Anvin wrote:
> Ram Yalamanchili wrote:
>> Thanks for the fix. I'm ok with waiting to 3.40.
>>
>> Another question would be, would you want to provide a library
>> function which can allocate the memory in the fashion 0x19h needs it:
>> aligned and not crossing 64k boundaries?
>>
>> I am not sure if static allocation of a variable and using it's
>> address will work since it might be above the 16bit address range.
> 
> Not just might, but *will* be.
> 
>> eg: char sectorBuf[64*1024*2] and getting an address within it which
>> is aligning to 64k.
>>
>> If you dont think the lib function is a good idea, what options do i
>> have other than using the bounce buffer?
> 
> None.  The bounce buffer is actually by definition *all* the memory 
> below 1 MB available to the COM32 program.
> 

By the way, the best way to use the bounce buffer is really to consider 
it local around the intcall: copy your data to the bounce buffer 
immediately before invocation, and copy your data from the bounce buffer 
immediately after.  This is pretty much what the library functions 
should do.

	-hpa