Re: GuixSD bootable ISO-9669 image

[ludo@gnu.org (Ludovic Courtès)]

Heya,

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> On Tue, 02 May 2017 14:37:04 +0200
> ludo@gnu.org (Ludovic Courtès) wrote:
>
>> Seems to work!
>
> Nice :)
>
>> Could you clarify the two “See grub” in here:
>> 
>> --8<---------------cut here---------------start------------->8---
>> (define (iso9660-superblock-uuid sblock)
>>   "Return the Volume ID of a iso9660 superblock SBLOCK as a 4-byte bytevector."
>>   ;; Note: The field is the volume creation time.
>>   ;; FIXME Use only certain parts (See grub).
>>   ;; FIXME treat "all 0" as invalid.
>>   (sub-bytevector sblock 813 17))
>
> Yeah.  If you check out grub, /dev/disk/by-uuid or blkid, you can see that for ISO9660 filesystems, it prints the "uuids" differently (because they are not uuids, they are timestamps...).

OK.  Are these “UUIDs” 160-bit long like the “real” ones?  If they are,
I’d suggest ignoring the problem for now.

>> Should ‘iso9660-uuid->string’ be different from ‘uuid->string’?
>
> From a purity standpoint I'd say no.  From a compatibility standpoint, yes.

Makes sense.

>> Anyway, I think we should polish and commit real soon.  :-)  Perhaps we
>> can add a note about endianness and assume little endian for now.
>
> Turns out that for the parts that we need we don't care about the endianness either way.  So I dropped the endianness now.

Cool.

Thanks,
Ludo’.