Re: GRUB SYSLINUX booting from logical partiton on USB drive

[greenfinch]

>     sdb1   Primary fat32 ~ 800MB
>     sdb2   Primary fat32 ~ 800MB
>     sbd3   Primary fat32 ~ 800MB
>     sdb4   Extended partition
>     sdb5   Logical partition ~ 800MB
>     sdb6   Logical partition ~ 600MB
>
>
>     - sdb5 was made bootable by:    syslinux -sf  /dev/sdb5  
>      (SYSLINUX version 3.63)
>
>     ---
>     My question is, why there is the boot error?
>     Thank you for your answer.
>
>  
>  
> Did you install syslinux files to the sdb5 partition before running 
> syslinux -sf ?
> Did you try to install it without the s option?
> What filesystem is found in sdb5? syslinux only accepts FAT partition.
>  
> If it is a ext3 partition you should use extlinux.
>  
> adrian15
>  

- The filesystem on the logical partitions sdb5 and sdb6 is fat32
- sdb5 was empty, after the Damn Small Linux zip-file was unpacked into 
the root of sdb5
- I called /.syslinux -sf /dev/sdb5 from another usb stick, where I have 
put the currrent SYSLINUX version 3.63.
- Manually, I did not copy any SYSLINUX files to sbd5. Only the file 
ldlinux.sys was copied to sdb5 automatically, when executing the 
syslinux command.
- I just tried without the option -s -> ./syslinux -f /dev/sdb5 -> same 
message 'Boot error'
If you have any ideas what I should change in my setup, feel free to 
tell it.


I already asked the same question to the SYSLINUX developers.
They told me the following:

----

Last I checked, Grub passed an invalid partition offset in DS:SI when 
chainloading a logical partition.  Syslinux is partition-table-format 
agnostic, and uses the information passed into it.  However, the format 
of DOS partition tables are such that anything that tries to boot a 
logical partition (keep in mind that MS-DOS couldn't boot logical 
partitions at all) has to adjust the partition offset; the stuff that 
comes off the disk is relative to the extended partition that surrounds 
the logical partition, but the chainloaded operating system has no way 
of knowing that.

-----

I'm not very familiar with 'partition offset' or 'DS:SI', but maybe you 
can have a look at it and it can help us
with my problem.

greenfinch