[syslinux] How to install manually?

[Gene Cumm]

On Tue, Dec 20, 2016 at 7:14 AM, piranna--- via Syslinux
<syslinux at zytor.com> wrote:
> I'm trying to install SysLinux on a disk image as part of NodeOS
> automated build process, but seems SysLinux requires administrative
> priviledges. I suposse this is needed because `syslinux` command try
> to mount the disk image / device to store the needed files, that
> otherwise would be have been written before and this step omitted. The
> other half would be to write the MBR bootloader, that would not
> require administrator permissions at all because it would use file
> permissions in that case. Only missing point would be if the MBR
> bootloader would need to know exactly what's the disk sector where's
> the start of LDLINUX.SYS file, but this could also be given with a
> parameter if it's known in advance.
>
> So my question is: why are needed administrative permissions to
> install SysLinux in a disk image? Is any alternative for that, or

bios/linux/syslinux operates like that to install ldlinux.sys.

> could it be implemented? If that's not possible, what's doing SysLinux

Consider bios/mtools/syslinux

> on the disk image MBR and/or content so I can be able to replicate it
> with a script?

In addition to dropping ldlinux.sys, the installer modifies the VBR
and ldlinux.sys to contain a map of the remaining sectors of
ldlinux.sys (not the start).  If you read the source of the installer,
you'll see it's not a trivial task.  The installer on Linux shouldn't
be touching the MBR unless this is a non-partitioned image file and
the first sector is actually the VBR.

-- 
-Gene