Loading therm_* modules in d-i on Macs

[Colin Watson <cjwatson@debian.org>]

It'd be rather nice if the new debian-installer could load the
therm_adt746x or therm_windtunnel modules, and register them so that
they're automatically loaded by the installed system.

I can take care of the d-i implementation, but what's the best way to
decide whether the modules are required? As I see it, there are two
obvious methods:

  (1) Probe each module unconditionally on powerpc/powermac_newworld,
      and register it in /etc/modules if modprobe exited 0. The modules
      in question check for the required hardware themselves and exit
      -ENODEV if they don't find it.

    Pros: simple; should be effective.

    Cons: brute-force approach; generates spurious errors which will
    probably have to be logged just in case anything real goes wrong;
    won't register the module if it's needed by the hardware but the
    probe failed for some installer-specific reason.

  (2) Take the logic from the respective module *_init functions,
      reimplement it in shell by poking about in /proc/device-tree (I've
      looked at the kernel code and believe this is straightforward),
      and probe and register whatever that says will work.

    Pros: accurate about what should go in /etc/modules, regardless of
    glitches in the installer environment; no spurious errors, only real
    ones.

    Cons: code duplication, so would have to stay in sync with the
    kernel (although d-i's kernels won't rev very often once we go
    stable); more complex.

Do any kernel hackers have an opinion here?

Thanks,

-- 
Colin Watson                                  [cjwatson@flatline.org.uk]