[lug] RH, syslinux, iso config

[D. Stimits]

I am running into a question about the mechanics of CD booting.
Especially non-emulation mode, should that apply, but probably is
irrelevant here. There is a specification for a boot catalog. This is
supplied as a fixed file in the isolinux and syslinux packages. It is
not created by the end user of the product. How is the catalog created
originally? Conceptually, what is its job? Is there a time, when
modifying a boot cd, that the boot catalog (boot.cat for RH) would also
have to be modified from its original content?

D. Stimits, stimits at idcomm.com 


"D. Stimits" wrote:
> 
> Kevin Fenzi wrote:
> >
> > >>>>> "D" == D Stimits <stimits at idcomm.com> writes:
> >
> > D> I had asked at the meeting about the proper location of boot images
> > D> for syslinux (actually, isolinux, since it is the CD version,
> > D> rather than floppy). One suggestion was to simply look at RH's cd
> > D> 1, which I now have mounted. Actually it is the cheap bytes
> > D> version, but what the heck.
> >
> > D> I can't find anything like the required isolinux.cfg (or anything
> > D> *.cfg or *.CFG). It is obvious that the boot.img is in the images/
> > D> subdirectory, but then I notice there is also a
> > D> dosutils/autoboot/cdboot.img. Is the autoboot version the original
> > D> boot image, while the images/ subdirectory contains selectable
> > D> images once the initial boot is up?
> >
> > The config files should be in the boot.img file...
> > do:
> >
> > mount -o loop images/boot.img /mnt/floppy
> > and look in /mnt/floppy...
> 
> The key seems to be it is type vfat. I tried mounting on loopback as
> iso9660, but this is a direct floppy image, rather than iso9660.
> 
> >
> > those would be for syslinux tho... I don't know anything about
> > isolinux...
> 
> isolinux is the analog to syslinux, but it is for cd roms. It uses the
> no-emulation mode, so the image used is not restricted by floppy size
> matching. Unfortunately, this is also the part that is failing :( The
> docs really suck, they simply say to look at syslinux for a lot of
> things, and syslinux.doc seems to assume we will read the mind of the
> author (for example, isolinux.doc says to consult syslinux.doc for the
> isolinux.cfg contents; looking at syslinux.doc there is a description of
> configuration file for syslinux.cfg, but nowhere does it say that
> isolinux.cfg uses this same syntax...it is assumed the reader will
> figure this out...it would be so much simpler if they just stated that
> syslinux.cfg and isolinux.cfg were the same thing with a different
> name). Anyway, isolinux is mandatory because my kernel will not fit
> within a normal floppy, even if it is allowed 1.8+ MB...I need over 2.3
> MB. Anyway, the days of 1.44 MB boot floppies is limited, there are a
> number of setups that need more than this now, and quite a few systems
> now force the floppy to be formatted for 1.6 MB or 1.8 MB, which is
> pushing the technology. Once you get to XFS filesystem and scsi as boot
> time requirements, this is broken.
> 
> isolinux is at:
> http://syslinux.zytor.com/iso.php
> 
> >
> > D> Considering that no matter where I place the image, it can't be
> > D> found, but also considering that it looks for the right image name,
> > D> I have to wonder if I have maybe jumped through necessary hoops,
> > D> but not enough of them. And the RH cd does not have the isolinux
> > D> directory, nor a syslinux directory, and nothing named *.cfg or
> > D> *.CFG, so what am I missing? Clues or suggestions? Do the KRUD
> > D> people have an isolinux.cfg I can borrow? Or maybe my scheme of
> > D> directories is wrong: cd root--/isolinux/ |-....
> >
> > might also need a lilo step in there to tell it where to find the
> > kernel in the boot image...?
> 
> Is lilo run on boot cd's? I wasn't even aware they had the equivalent of
> a boot sector. My understanding is that this is what the mkisofs options
> are for, to name the boot image. At boot time, it does indeed state that
> it is looking for the image of the name given, but it can't find
> it...even though it is plainly there...I tried all kinds of variations,
> it just cannot see it.
> 
> D. Stimits, stimits at idcomm.com
> 
> >
> > D> Testing variations is painfully slow, it involves uploading on a
> > D> 56k modem, then downloading on a 33.6k modem to get to the cd
> > D> burner.
> >
> > ouch! ;(
> >
> > kevin
> > --
> > Kevin Fenzi
> > MTS, tummy.com, ltd.
> > http://www.tummy.com/  KRUD - Kevin's Red Hat Uber Distribution
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