[syslinux] Advice/directions to users of Syslinux

[Thomas Schmitt]

Hi,

Ady wrote:
> I personally don't like this "hiding" [of CHS], but I understand
> their reasons to do so.
> 
> I think that the "USB-Geometry" section in the wiki should try to 
> point to the same kind of users.

But it is in wiki page Hardware_Compatibility.
Check out the neighborhood.
If there is a place to - for once - state how a "normal" partition
table should look like, then there.

The user of partitioning tools shall rather be directed to
the text which currently evolves at
  http://www.syslinux.org/wiki/index.php/User:Scdbackup#New_Common_Problems_Bad_Heritage_on_MS_DOS_disk
and only at the end of that section, there will be a link
to Hardware_Compatibility#USB-Geometry.


> Once the user chooses the partitioning tool, he has to change the 
> geometry to make it adequate. Whether the alignment is one or the 
> other, it shouldn't matter (in the context of the Syslinux wiki, and 
> trying to improve bootability).

We have strong evidence meanwhile that Ronald's two problem sticks
both bear deceiving H and S in their end CHS. See
  ftp://ftp.tristatelogic.com/private/ady/ubcd.0
     end CHS is  969, 21, 21
  ftp://ftp.tristatelogic.com/private/ady/oe.0
     end CHS is  492, 150, 42

We do not know for sure whether changing the end CHS of
ubcd to 242,254,63 would fix it.
But i think everybody will agree that "22 heads, 21 sectors/track"
is not the best start for a SYSLINUX installation.


> One typical problem for users: they forget to set the partition as 
> "active". So then they don't understand why their USB drive is not 
> booting.

Ok. This is now mentioned in
  User:Scdbackup#New_Common_Problems_Bad_Heritage_on_MS_DOS_disk


> In a very broad view, there are effectively two options so to improve 
> bootability:
> _ Nx255x63, one-and-only partition with MiB alignment

I hope for the partitioning tools to guide the user.

But MiB alignment does not match 255x63 cylinders. (Or at least
only in very large steps. They share no prime factors except
the block size.)


> _ ZIP-like geometry, optionally / alternatively using the fourth 
> partition only.

That would be option -4 of mkdiskimage.
Its helptext is shown in my partition-tool-oriented text.
So the reader can easily get to that idea.

I could need examples of original successfull runs of mkdiskimage.
Do we have any happy users of this tool here ?


> IMHO, getting into more details with specific CHS values and examples 
> might derail and/or discourage users, who, after all, just want to 
> boot their USB and move on.

Thus the careful escalation of detail.

Beginning by:
"In order to create a bootable disk using SYSLINUX, prepare a
 normal MS-DOS formatted disk. If you are in doubt that your
 disk is normal enough, see this description
 [[Common_Problems#Bad_Heritage_on_MS_DOS_disk|this description]]."

which leads the user to:
"The wiki prescribes to install SYSLINUX into a normal MS-DOS
 formatted disk. Depending on the history of your disk or pen drive,
 it might be less normal than needed. You will learn by SYSLINUX
 failing to boot properly."

followed by a generic prescription for setting up the disk
from scratch.
Then comes the help text of mkdiskimage and hopefully a few
examples for the operating systems mentioned in the main wiki.

Finally a link to the die-hard article
  http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB_related_problems


> I would say that for Windows users the problem might be, 
> independently of the geometry, discovering that the USB drive might 
> contain additional partitions in 
> the first place (note: Windows normally won't let the user see more 
> than one partition in USB removable flash drives).

Even more reason to give them an example with mkdiskimage
which can be executed more or less blindly.


---------------------------------------------------------------
Intermediate summary:

I defend Hardware_Compatibility#USB-Geometry until more people
join Ady's opinion that it is more confusing than helping.
(I count Gene on my side :))
We both made our points by now.
The article is sufficiently hidden to do not much harm until
we come to a final decision.

I try to bring Ady's points into a new article
  Common_Problems#Bad_Heritage_on_MS_DOS_disk
which shall make proposals on application level.
It is evolving at:
  http://www.syslinux.org/wiki/index.php/User:Scdbackup#New_Common_Problems_Bad_Heritage_on_MS_DOS_disk

@Ady:
Did i represent your points sufficiently here ?
Anything i skipped by mistake ?

---------------------------------------------------------------

Have a nice day :)

Thomas