Re: Dropping CDs entirely?! (was: Stretch Alpha 3 images)

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Aurelien Jarno wrote:
> I have no idea if they support booting over a
> CD-ROM or USB image. Does someone known if we can do so on a Loongson 3
> or Octeon machine?

Maybe one should ask grub-devel@gnu.org mailing list or
Vladimir Serbinenko directly.

---------------------------------------------------------------

Option --format in
  man grub-mkimage
shows several mips-ly names:
  mipsel-yeeloong-flash, mipsel-fuloong2f-flash, mipsel-loongson-elf,
  mips-arc, mipsel-arc

---------------------------------------------------------------

  man grub-mkrescue
talks of "big-endian MIPS machines".
Some day i must learn how GRUB2 prepares itself for the
run of grub-mkrescue and defines which xorrisofs options
to use.
Among these options are

  -mips-boot /boot/grub/mips-arc/sashARCS
  -mips-boot /boot/grub/mips-arc/sash
  -mips-boot /boot/grub/mips-arc/grub

which activate these files (<iso-path>=<disk-path>):

  /boot/grub/mips-arc/grub=${iso9660_dir}/boot/grub/mips-arc/core.img
  /boot/grub/mips-arc/sashARCS=${iso9660_dir}/boot/grub/mips-arc/core.img
  /boot/grub/mips-arc/sash=${iso9660_dir}/boot/grub/mips-arc/core.img

Two years ago there was no option -mipsel-boot to see.
I.e. only big-endians were supported.

---------------------------------------------------------------

It may well be that the machines make no difference
between booting from CD and booting from hard disk.
At least the boot sectors of -mips-boot and -mipsel-boot
look much more like MBR than like El Torito.

So if we learn how grub-mkimage composes the image
for mipsel-loongson-elf, i could possibly teach libisofs
how to create the necessary boot record.

... if mipsel-loongson-elf is what boots Loongson 3.


Have a nice day :)

Thomas