[syslinux] Custom MBR

[YYZ]

Hi,

Is it possible to always load syslinux from whichever partition it’s installed on, regardless of whether it’s active or not (and even if it’s a logical partition), just like grub?

The MBR code that ships with syslinux (much like dos/windows default MBR) would only boot the active primary partition. It would be nice if you could provide a custom MBR such that one could set one byte in the MBR indicating which partition should be booted (0,1,2,3 for primary/extended and 4,5,6,… for logical) and install it in the sector 0. Thereafter, upon system restart, instead of searching for active partitions, the MBR could would just load the correct boot sector and execute it. The code to read each successive extended partition table (in case of logical partitions) would need to be added, but I see that there’s already some unused space available. 

Is this possible to do this using just 440 bytes? If not, maybe, the CHS code could be knocked off since most people use newer bios now-a-days?

Thanks,
YYZ