[syslinux] Trouble with Ubuntu 15.10 / syslinux 6.03

[Celelibi]

2015-12-09 11:19 UTC+01:00, Hadmut Danisch via Syslinux <syslinux at zytor.com>:
> Hi,
>
> I'm looking for a hint about what has changed in syslinux 6.03.
>
> Some years ago I had written a script that configures a bootable USB
> pen drive with syslinux and some boot images, which still worked well
> under Ubuntu 14.04 LTS and previous versions, but does not work
> anymore under Ubuntu 15.10 with syslinux 6.03.
>
> I've boiled this down to a test-script that isolates the problem:
>
>
> -------------------------------------------------------------------
> #!/bin/bash
>
> device=/dev/disk/by-id/usb-SMI_Corporation_CnMemory_00040127008368-0:0
> device=`realpath $device`
> echo "Device $device"
>
> if [[ ! -b $device ]] ; then
>   echo 1>&2 "Device $device missing"
>   exit 1
> fi
>
> parted -s $device rm 1 || :
> parted -s $device rm 2 || :
> parted -s $device rm 3 || :
> parted -s $device rm 4 || :
>
> parted -s $device mkpart primary fat32 0MB 4000MB
> parted -s $device set 1 boot on
>
> blockdev --rereadpt $device
>
> sleep 2
>
> dd if=/usr/lib/SYSLINUX/mbr.bin of=$device
>
> mkdosfs ${device}1
>
> syslinux --install ${device}1
>
> kvm -drive file=${device},format=raw
>
>
> -------------------------------------------------------------------

It's very probably not the problem here, but when you get a weird low
level bug in KVM, you may want to make a test run in a simple QEMU
without KVM.

Just for information: there's a bug in the KVM kernel module for Linux
4.2 and 4.3. This bug at least affects OVMF which in turn affects
syslinux. But as I said, it's very probably a known bug with gcc 5,
not with KVM.

>
>
> That script works under 14.04 LTS and creates a running pendrive
> (i.e. syslinux boot process reaches the point where it complains about
> the missing config file as expected, the test script does not install
> a config file)), while on 15.10 with syslinux 6.03 it creates
> a USB device that can't boot, it just brings the lines
>
> SYSLINUX 6.03 EDD 20150813 Copyright...
> Boot error
>
>
>
> What has changed between syslinux 6.03 and the older version in Ubuntu
> 14.04, that causes this different behaviour?

As mentioned by Ady, a previous occurrence of this bug has been
reported in ubuntu: same error, same ubuntu version, same usage.
https://bugs.launchpad.net/ubuntu/+source/usb-creator/+bug/1499746
It seems to be marked "fix released". So I guess you may just upgrade to fix it.

And the discussion on the syslinux ML about it:
http://www.syslinux.org/archives/2015-November/024539.html


Best regards,
Celelibi