Re: Bug#461442: detection of other OSes in update-grub

[Fabian Greffrath <greffrath@leat.rub.de>]

Robert Millan schrieb:
> Sure, we can fix grub-probe.  This was already needed for something else
> (but I forgot what ;-)).
>   

Nevertheless it will be very very convenient to have this in grub-probe.

> Can you propose a CLI by which grub-probe would be told to process devices
> rather than mount points (in grub-devel)?  The hard part here is not the code,
> but coming up with a consistent interface (the code is rather trivial, since
> the conversion operation is completely isolated).
Sure, CCing grub-devel.

We should stay with the '-t drive' option to print the GRUB drive. If no 
further option is given, the next item on the command line is expected 
to be a path - just like before.
Then, another option, e.g. '-o', should be introduced to specify the 
origin of the said item if it is different from "path", e.g.:

$ grub-probe
Usage: grub-probe [OPTION]... [ORIGIN]

Probe device information for a given path or, if the -o option is given, 
for a given GRUB drive or system device.

  -m, --device-map=FILE     use FILE as the device map 
[default=/boot/grub/device.map]
  -t, --target=(fs|drive|device|partmap|abstraction)
                            print filesystem module, GRUB drive, system 
device, partition map module or abstraction module [default=fs]
  -o, --origin=(path|drive|device)
                            expect to read from path, GRUB drive or 
system device [default=path]
  -h, --help                display this message and exit
  -V, --version             print version information and exit
  -v, --verbose             print verbose messages

This way it will be possible to even convert back and forth between GRUB 
drives and system devices.
The conversion that is needed to translate os-prober output to GRUB menu 
input will read:
GRUB_DEVICE="`grub-probe -t drive -o device ${PARTITION}`".

Hope you like this proposal (of course, "origin" is subject to change; 
it's just the first word that came to my mind that might be fitting)!

Cheers,
Fabian

-- 
Dipl.-Phys. Fabian Greffrath

Ruhr-Universität Bochum
Lehrstuhl für Energieanlagen und Energieprozesstechnik (LEAT)
Universitätsstr. 150, IB 3/134
D-44780 Bochum

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E-Mail:  greffrath@leat.ruhr-uni-bochum.de