[syslinux] FW: boot fails on some system

[Jethro Tull]

On Sat, 15 Apr, 2017,  9:11:34 +0200, Martin Str|mberg via Syslinux wrote:

[ ... ]

> system (although this might be a last resort), etc. And/Or use the
> mbr.bin files from different syslinux versions. Make sure to not
> disturb the partitioning when doing this ("bs=440 count=1").
> 
> Can you make it boot then?

I tried a lot from old to recent usb live linux using a non partionned usb
pendrive. None of linux systems have booted the failling computer. On the
other side the first usb booting system I found in windows worked perfectly.
This is the "HP USB Disk Storage Format Tool, V2.1.8" which can be used to
make a DOS startup disk. It didn't accept the dos partition made by mkdosfs
and reformatted itself. I don't know why but most often windows tools reject
any dos partition made by a linux tool.

As I'm not so familiar and up to date with MS software this is the first and
only thing I found to get a usb booting system. I then tried its 440 bytes
from mbr for booting a live linux it resulted in a very weird and random
thing.

> 
> If so yI don't know why but most often windows tools reject any dos partition made
by a linux tool.
ou can compare the mbrs to see what's different if you want.
> 
> 
> For the partitioning:

[ ... ]

> Do zero out the partition table first so you don't "inherit" any
> badness ("dd if=/dev/zero of=/dev/sdx bs=512 count=1 conv=sync").
> Actually before destroying the partition table, I'd zero out the
> beginning of all and any partitions ("dd if=/dev/zero bs=1024k
> count=10 conv=sync of=/dev/sdxX" x Y) first, as we are in starting
> from scratch mode. (If there were RAID/GPT involved I'd zero out
> the end of partitions/disk respectively too.)

I most often do zero the 512 bytes of the mbr before proceeding to
partitionning, and for the latter I use fdisk. Zeroing the ten first MiB of
each partition? not this, I never did this. I'll try.

> 
> Further making starting first partition start on sector 2048 or 63 or
> whatever new USB sticks have (I've seen really weird starting sector
> on them like 8064) could make a difference. I've seen a new UEFI
> system fail to BIOS boot with the partitioning of/from a new USB stick
> (not relevant here).

fdisk by default starts the first partition at 2048 bytes. Maybe you want to
know about alignment.  I always use the starting address given by default by
fdisk and I always round my partitions to MiB.

> -- 
> MartinS