[SOLVED] Remastering install media

integer · 2014-09-16 10:13:41

Hi folks, I need some help with a custom archiso.

I'm trying to follow the instructions in the wiki describing
remastering the live media, and it seems that there's a problem
with actually generating the iso image. I can't seem to get a bootable
usb drive even if I simply mount the 'proper' live media, copy it over
into a new directory, and then try to generate the same image using
that directory.

After mucking around a bit, I tried using the geniso options that
are scripted into the archiso scripts, but there I get even more problems,
with genisoimage complaining about deprecated options.
When I remove the seeming culprits, I still fail to get a bootable iso.

Mounting and comparing the two images, there is a clear difference:

/dev/loop0: UUID="2014-09-03-15-30-04-00" LABEL="ARCH_201409" TYPE="iso9660" PTUUID="4f6c5b3c" PTTYPE="dos"
/dev/loop1: UUID="2014-09-11-19-33-24-00" LABEL="ARCH_201409" TYPE="iso9660"

loop0 is the official arch live media, while loop1 is my generated image.
What's even more troubling is that isoinfo reports quite varied information
for the two images (below is a diff of the output of isoinfo for the two
different images):

14,15c14,15
< Volume size is: 293888
< El Torito VD version 1 found, boot catalog is in sector 42
---
> Volume size is: 391152
> El Torito VD version 1 found, boot catalog is in sector 40
17c17
< Rock Ridge signatures version 1 found
---
> NO Rock Ridge present
21c21
< ID ''
---
> ID 'Arch Linux <http://www.'
29c29
< Bootoff 3E2B 15915
---
> Bootoff 29 41

Here is the command I am using to generate the iso image:
genisoimage \
-iso-level 3 \
-full-iso9660-filenames \
-volid "${iso_label}" \
-appid "${iso_application}" \
-publisher "${iso_publisher}" \
-preparer "prepared by mkarchiso" \
-eltorito-boot isolinux/isolinux.bin \
-eltorito-catalog isolinux/boot.cat \
-no-emul-boot -boot-load-size 4 -boot-info-table \
-output arch-custom.iso \
${work_dir}/archiso_cust/

It would be great if someone can point me in the right direction.
genisoimage seems to fairly well documented, but is also rather
expansive, and having very little experience with iso9660, I was
hoping that someone could spot my error.

Just as a disclaimer, I know that the better way to generate Arch
live media is to use the actual archiso scripts, BUT, remastering
the existing live media should be possible, and I want to know
where I'm making a mistake.

Many thanks in advance.

Last edited by integer (2014-09-18 20:27:38)

nomorewindows · 2014-09-16 15:47:39

You'd probably need netbootin to get it from an archiso to a usb image. They don't exactly work the same. Or you could use diskless nfs root if this your own network.

teateawhy · 2014-09-17 14:20:38

How do you try to boot the remastered image? A while ago i remastered the live media and used dd to write it to a usb stick. The usb stick failed to boot. When i booted the image directly from grub, instead of using dd, it worked.
Then i opened a forum thread about this, where i was told to use the archiso scripts instead.
Using archiso really is the better way.

integer · 2014-09-18 17:00:02

teateawhy wrote:

How do you try to boot the remastered image?

Just by dd the image onto a USB key and boot from media. It's not booting.

teateawhy wrote:

A while ago i remastered the live media and used dd to write it to a usb stick. The usb stick failed to boot.

Yes, exactly the problem that I'm having.

teateawhy wrote:

Then i opened a forum thread about this, where i was told to use the archiso scripts instead.

I could not find this post.

teateawhy wrote:

Using archiso really is the better way.

Yeah, I guess I'll try that.
But I'm still curious about this problem. Clearly I'm missing either some genisoimage parameters, or I'm missing an extra step that creates a bootable partition with the bootloader on the USB key, but I am not able to find this information.

Tarqi · 2014-09-18 19:00:02

Try Isohybrid.

integer · 2014-09-18 20:27:09

Tarqi wrote:

Try Isohybrid.

Well, that did it.

Basically, instead of a straight genisoimage or mkisofs, it's necessary to use

$ xorriso -as mkisofs

as in the the mkarchiso script.

I've updated the wiki.

Thanks, Tarqi!

Tarqi · 2014-09-18 21:40:09

You're welcome. As for the wiki: You wrote, when using genisoimage, one will not get a bootable image. Did you mean, a bootable USB image? The .iso burned to a CD should be bootable, I think. And if you inspect the xorriso command in the wiki, you will find, that it will use isohybrid too, just in another way

Last edited by Tarqi (2014-09-18 21:42:14)

Arch Linux

#1 2014-09-16 10:13:41

[SOLVED] Remastering install media

#2 2014-09-16 15:47:39

Re: [SOLVED] Remastering install media

#3 2014-09-17 14:20:38

Re: [SOLVED] Remastering install media

#4 2014-09-18 17:00:02

Re: [SOLVED] Remastering install media

#5 2014-09-18 19:00:02

Re: [SOLVED] Remastering install media

#6 2014-09-18 20:27:09

Re: [SOLVED] Remastering install media

#7 2014-09-18 21:40:09

Re: [SOLVED] Remastering install media

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