[syslinux] isohybrid question

[Miller, Shao]

Good day Thomas Schmitt and H. Peter,

Being largely isohybrid-ignorant but having tried to comprehend the
(dated) discussion, I was wondering: What is the reason why an ISO9660
filesystem (and image) generator cannot reserve space for various items
without putting anything but zeroes there, then a later post-processing
utility can fill the reservations with user-selected data and adjust any
checksums?  Or is this exactly what happens?  (I'm not left with that
impression.)

I ask because it seems that there is a little bit of a circular
dependency.  In some checksumming algorithms, the checksum field is
filled with zeroes since it isn't known what goes there yet. :)

Perhaps an .ISO generator could have no knowledge about Syslinux
particulars, beyond how much space is desired to accomplish the general
isohybrid shape?  If an .ISO can be padded by the post-processor, would
that satisfy any fractional cylinder boundary concerns for the
partition's end?

I apologize in advance if it's a ridiculous or half-baked idea.  I was
pondering how easily one might plug in additional (customized) MBRs or
even a different approach.

- Shao Miller

-----Original Message-----
From: syslinux-bounces at zytor.com [mailto:syslinux-bounces at zytor.com] On
Behalf Of Thomas Schmitt
Sent: Wednesday, March 31, 2010 06:27
To: syslinux at zytor.com
Subject: Re: [syslinux] isohybrid question

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