Monte development

[rc3105]

name says it all, this is the place to discuss it if you're a developer

for general usage / questions / howto, go here


*good rule of thumb, if you don't have a working compiler you should stick to posting in the support threads

[Jamie]

Here's a very minor contribution. I hesitate to even include this in a development thread, but I did use a cross-compiler...

It seems that the kmonte.o that most people use only works with a 2.4.4 kernel. I modified the kmonte.c source very slightly to add the MODULE_LICENSE macro call (avoids tainted kernel warnings), and built it for 2.4.18 and 2.4.20.

Why would you want this? Well, with this you can boot an lba48 aware kernel (e.g. a signed killhdinitrd'd 2.4.20 kernel from 3.1.5) then monte to wherever you like. In my case I wanted to monte into a kernel that happened to lie above the lba28 mark. With a 2.4.4 kernel and the 2.4.4 kmonte.o, I couldn't do it. You can also freely monte between 2.4.4, 2.4.18 and 2.4.20 now, instead of just from 2.4.4 to something else. That's good for slight amusement, but probably little else.

If you don't understand any of this, you probably don't need it. Just keep monte'ing the way you always have.

{Edit: The 2.4.18 and 2.4.20 kmonte.o has been found to be unreliable. It works with some combinations of to and from kernels, but not with others. Read on in the thread for details. }

[Jamie]

Note that there is some discussion about whether a monte from a cold start on 2.4.20 to 2.4.18 or 2.4.4 will work. I haven't tested that case but will. So this probably isn't ready for prime time yet.

{edit 20041119: I've now tested all variations of montes to/from 2.4.4, 2.4.18, 2.4.20, and all worked on my hardware (S2SA).}

[Jamie]

I've now tested all variations of montes to/from 2.4.4, 2.4.18, 2.4.20, and all worked on my hardware (S2SA).

Just to follow up on this, I have now observed a few kernel crashes when monteing from 2.4.18 and 2.4.20. It seems to be a property of the destination kernel. I have one home built kernel that works fine as a target kernel from all three (this one). If I go back and rebuild the kernel with a slightly different kernel config, I can monte to it from 2.4.4 but I get crashes when monteing from 2.4.18 or 2.4.20.

So I'd still consider anything but 2.4.4 monte experimental and not ready for prime time.

[Gromit]

... I have now observed a few kernel crashes when monteing from 2.4.18 and 2.4.20. It seems to be a property of the destination kernel. ...

When it crashed, did that happen right at the time you ran monte, or some random time later? Or to put it another way, if my monte appears to successfully load the destination kernel, and the subsequent boot 'appears' normal (no obvious errors) can I be fairly confident that the monte worked?

I just monted an S2 HDVR2 v6.2 from a killhdinitrd'd 3.1.5 kernel to the S2_Unscramble 2.4.20 kernel. The monte and reboot appear OK .

[Jamie]

When it crashed, did that happen right at the time you ran monte, or some random time later? Or to put it another way, if my monte appears to successfully load the destination kernel, and the subsequent boot 'appears' normal (no obvious errors) can I be fairly confident that the monte worked?

I just monted an S2 HDVR2 v6.2 from a killhdinitrd'd 3.1.5 kernel to the S2_Unscramble 2.4.20 kernel. The monte and reboot appear OK .

The crash happened consistently and every time with the same combination of 'from' and 'to' kernels. So if you have something that is working, it should continue to work. Just be aware that it might be fragile. For example, if you change either kernel, it might stop working.