Hi,
> - the first 32K of an ISO9660 is undefined
That's such a negative word. :))
It is "reserved for system use" and "not specified" by ISO 9660 / ECMA-119.
> - boot.S and diskboot.S get built into cdboot.img
grub-mkrescue opens cdboot.img for reading and the image file for -G
for writing and truncates it to 0 length. Then it writes 512 zero bytes,
reads 512 bytes from cdboot.img and writes them to the -G image file.
> - grub should run xorisso with the following parameters:
> -G cdboot.img -B "..." --grub2-sparc-core
> /boot/grub/sparc64-ieee1275/core.img
Actually these are for the mkisofs emulation of xorriso.
xorriso -as mkisofs ...options.and.pathspecs...
(See man xorrisofs for options.)
Note that
-B ','
as of grub-mkrescue is not totally equivalent to your
-B '...'
Digging in libisoburn's xorriso/emulators.c i see that "," orders two
appended partitions with empty disk source paths. This will cause no
partitions to be appended.
"..." causes 7 partitions copying the partition entry data of the entry
before them. That would be the entry describing the ISO image as a whole.
Again no partitions images get appended.
One should test both and inspect by SUN tools or
xorriso -indev $ISOIMAGE -report_system_area plain
Probably "..." will produce a partition table with 8 entries, and ","
will produce a table with only one entry.
> - what this effectively does is:
> - Install a sun partition disk label to sector 0 of the ISO image
> - Add the ISO9660 image as the first partition (slice)
> - Create all 7 remaining partitions after the ISO9660 image
I expect this too.
> - These partitions are all small and just contain cdboot.img
I expect what can be seen in debian-10.0-sparc64-NETINST-1.iso
Volume id : 'Debian 10.0 sparc64 n'
...
System area summary: SUN-SPARC-Disk-Label
ISO image size/512 : 284760
SUN SPARC disklabel: CD-ROM Disc with Sun sparc boot created by genisoimage
SUN SPARC secs/head: 640
SUN SPARC heads/cyl: 1
SUN SPARC partmap : N IdTag Perms StartCyl NumBlocks
SUN SPARC partition: 1 0x0004 0x0010 0 284160
SUN SPARC partition: 2 0x0002 0x0010 0 284160
SUN SPARC partition: 3 0x0002 0x0010 0 284160
SUN SPARC partition: 4 0x0002 0x0010 0 284160
SUN SPARC partition: 5 0x0002 0x0010 0 284160
SUN SPARC partition: 6 0x0002 0x0010 0 284160
SUN SPARC partition: 7 0x0002 0x0010 0 284160
SUN SPARC partition: 8 0x0002 0x0010 0 284160
xorriso command -pvd_info says:
App Id : GENISOIMAGE ISO 9660/HFS FILESYSTEM CREATOR (C) 1993
E.YOUNGDALE (C) 1997-2006 J.PEARSON/J.SCHILLING (C) 2006-2007 CDRKIT TEAM
...
Creation Time: 2019012014210500
You could put cdboot.img in there by naming it in the comma separated
list of paths after -B. But i guess you should not.
--------------------------------------------------------------------------
The following topics are out of my normal scope. So i can only throw in
text snippets which may be related:
> 1) How does boot.S/diskboot.S locate core.img?
man xorrisofs says about -B:
The pseudo disk_path "..." causes that all empty partition
entries become copies of the last non-empty entry. If no other
disk_path is given before "..." then all partitions describe the
ISO image. In this case, the boot loader code has to be imported
by option -G.
So having no boot images in the partition table is ok, in principle.
> This means that when the PROM opens the disk in boot.S, it is directly
> opening the partition containing cdboot.img rather than the start of the
> whole disk
It looks like all partitions lead to CD-ROM (where Nero burns).
> 2) How to launch xorisso with the correct parameters?
With two "r" and only one "s". :))
(xorriso = X/Open on Rock Ridge enhanced ISO 9660)
> grub-mkinstall
To what package does this belong ?
Google proposes to search for "grub-install". But i don't think that this
is for ISO 9600 production.
Have a nice day :)
Thomas
