[arch-releng] Note about removing archiso_early hook.
Gerardo Exequiel Pozzi
vmlinuz386 at yahoo.com.ar
Tue Mar 2 20:08:43 EST 2010
Hi, just to leave in some visible place this experiment if some is
My idea: remove archiso_early hook, and take the advantage of symlink
/dev/disk/by-label/XYZ created by 60-persistent-storage.rules installed
via udev hook, without doing other tricks.
* OK: when booting in cdrom mode.
* FAIL: when booting in disk mode.
The reason is because hybrid mode (via isohybrid).
* The LABEL is defined at first sector of iso "sda" (simulate a MBR)
also there is a fake partition "sda1" (with offset 1 [+512 bytes ahead
of sda]) so you can create another partitions on the destination media.
* When mount the UDF filesystem, sda is mounted and not sda1 (sda1 is
just a fake part to avoid overwriting data).
* There is a udev rule at 60-persistent-storage.rules that make all
parent (sda in this case) ID_* env data available to childrens (sda1 in
this case), so sda1 inherits the LABEL, and this data is not overwrited
because blkid fail (remember sda1 is not a real partition)
* /dev/disk/by-label/XYZ points to /dev/sda1 instead of /dev/sda. (when
isohybrid offset > 0)
* if offset = 0 will works, but doing this we lost the capability of
create another partitions in the medium that .iso is copied (USB media)
* Also works on real partition scheme (usb drive with the real MBR, and
real partiton with label)
* As said before if boot as cdrom.
* Keep with archiso_early, that is pretty simple and does not require
other tools [#1]
If some is interested in changes for your personal usage, the patch is
[#1] http://bugs.archlinux.org/task/18523 [mkinitcpio] usb_id, ata_id,
scsi_id, path_id: should be added to udev install hook?
Gerardo Exequiel Pozzi ( djgera )
Key fingerprint = 0CAA D5D4 CD85 4434 A219 76ED 39AB 221B 1B8C 330D
More information about the arch-releng