[syslinux] Booting

[H. Peter Anvin]

Jacob Alifrangis wrote:
> The boot loader on the Windows CD detects whether there is a partition
> located on device 0x80 (First BIOS Harddrive), if it does not see one,
> it boots from CD first, if it does it just asks you to "Press Any Key"
> 
> The logic you are looking for doesn't exist on PCs,
> 
> There isn't a firmware variable that is accessible from modern Operating
> Systems, especially not one that survives a reboot.
> 
> What you are looking to do, can be accomplished from a Com32 Module
> though, but you'll still need to set the bios Boot Order manually to
> always boot from USB (Which is exceedingly dangerous and insecure)
> 
> Your best bet to accomplish this, is writing a state-file to the
> harddrive on the boot partition(Must be 0x80h - 0x83h) or syslinux would
> never see it, then you must write a com32 module for NTFS and FAT /
> Fat32 so you can read the state-file, and finally act on it via an "If"
> statement, something that syslinux doesn't support either yet.
> 

Actually, 3.60 introduced persistent storage for extlinux, which could 
be used for this purpose.  It is currently missing installer support for 
syslinux, but the core module support is there.

But yes, you need to set the bios boot order to boot from whatever 
medium actually has syslinux on it.

	-hpa