[syslinux] boot speed

[H. Peter Anvin]

Jim Murphy wrote:
> On Sun, May 26, 2002 at 08:48:48AM +1000, websol1 wrote:
> 
>>From: John Plunkett
>>·
>>When Syslinux is used with floppy disks with a 1.44 MB format the boot
>>proceeds at a good speed with no problems.  When a format over 1.44 MB
>>is used, the boot takes up to ten minutes.  Is there a special setting
>>for booting from floppy disks over 1.44 MB's?
>>Is there documentation on how to configure with floppy disks with a
>>format over 1.44 MB's?
>>·
>>Thanks,
>>
> 
> 
> Interesting.  Not sure this is the same thing I'm seeing or not.  Mine
> may seem like 10 minutes, but it takes a long time to load initrd.gz
> and vmilunz.  The message file displays ok, but the loading, 3 maybe up
> to 4 times as long as normal.  But then, after "ready." prints out, it
> reboots and starts all over again.  Using 1.68 MB formatted floppy.
> Still troubleshooting, but don't know yet if it may be something I'm
> doing wrong.  Testing was with revisions 1.67 and 1.72.  I know its
> worked on earlier versions(1.48).
> 

Most BIOSes are highly cantankerous booting off extended-format 
floppies.  They may not be able to read more than a single sector at a 
time, and then have to wait for the floppy to rotate a full turn to read 
the next sector.  SYSLINUX will fall back on this mode of operation if 
it has to.  Note that *many* BIOSes can't boot extended-format floppies 
at all.

> BTW, I had an earlier posting on serial output as a console with no
> video card installed.  The message file only prints 15 characters on
> each line then wraps to the next line.  Everything after the message
> file prints ok.  Any ideas?
> 

Yes, the problem is that SYSLINUX gets the size of each line from the 
BIOS.  Apparently your BIOS leaves those variables containing garbage; 
in particular, the line width is set to 15.

Not much to do about, I'm afraid.  I might keep it in mind if I end up 
messing with that code, to handle wraparound differently for the serial 
port.

	-hpa