[syslinux] Good, bad and ugly

[H. Peter Anvin]

Quinn wrote:
> 
> H. Peter Anvin wrote:
> 
>>
>> The one thing that seems possible to go is the automatic search for 
>> LDLINUX.SYS.  The boot sector can hard-code the location of this file, 
>> or perhaps only the beginning of it.  This means the file cannot be 
>> moved, but it's already standard that a file with the System attribute 
>> set shouldn't be moved.  It also means it's no longer "just a file"; 
>> it will not be possible to copy it or write it with anything other 
>> than the syslinux installer, to the extent it ever was.
> 
> 
> Is this not what grub does currently?  The address for the next piece of 
> code is in the mbr and uses it to load the second stage loader - am I 
> correct?
> 
> I believe MS/PC-DOS does the same thing - it looks for IO.SYS/IBMBIO.COM 
> in the fat table, loads it, then executes it.

No, MS-DOS actually loads IO.SYS based on its directory entry, which is 
the "correct" thing to do.

> I'll vote for the last method - very similiar to the way DOS loads - and 
> your right - many defragmentation programs don't move files that have 
> the system bit on them.

Well, the last method (use directory/FAT) is what I currently do.  It's 
very "correct"... it just doesn't fit with EBIOS support.  DOS, btw, 
selects CBIOS or EBIOS (Win95 OSR2 or later only) at install time, only.

	-hpa