[syslinux] isohybrid question

[Thomas Schmitt]

Hi,

> How about zeroes?  Or is it ones?  Which burn better?

They get scrambled by the burner anyway :))


> Will optical media with an MBR ever be useful?

As master image for other media, perhaps.

A generalized behavior of all target media types
is nice too.

If it ever comes to dual tree ISO images, then
this needs close coordination with the partition
table in the MBR.


> that just a DD would be simpler than DDing the optical
> media to the disk, followed by the isohybrid post-processing?

Afaik, the isohybrid script is supposed to be
from the same Syslinux version as the ISOLINUX
files in the image. 
In any case you'd need Syslinux at that time.


>  A distribution could
> churn out batches of optical media with xorriso directly without having ever
> prepared an .ISO image, for example?

If i understood Steve McIntyre right, recently,
then he would like to combine Jigdo downloading
with MBR writing in genisoimage.
(Or we could teach xorriso to do Jigdo :))


> >  Max. 4 cylinders.
> Where does this maximum of 4 cylinders come from, if you recall?

4 disk blocks are one ISO/CD block.
So 4 times any integer number of disk blocks is
divisible by the ISO/CD block size.

In particular we have as possible division
residues of blocks_per_cylinder/4 :
0 -> Any integer number of cylinders is aligned.
     We choose 1.
2 -> Any even number is aligned.
     We chose 2.
1 or 3 -> Aligned only if number is divisible by 4
     We chose 4.


> It's probably the partition start that's more important for
> flaky C/H/S access.

I wonder how important or desirable it would
really be to have a non-0 start of partition 1.


Have a nice day :)

Thomas