33 lines
1.6 KiB
Plaintext
33 lines
1.6 KiB
Plaintext
This is Task 06 of the Eudyptula Challenge
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Nice job with the module loading macros. Those are tricky, but a very
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valuable skill to know about, especially when running across them in
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real kernel code.
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Speaking of real kernel code, let's write some!
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The tasks this time are:
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- Take the kernel module you wrote for task 01, and modify it to be a
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misc char device driver. The misc interface is a very simple way to
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be able to create a character device, without having to worry about
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all of the sysfs and character device registration mess. And what a
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mess it is, so stick to the simple interfaces wherever possible.
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- The misc device should be created with a dynamic minor number, no
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need running off and trying to reserve a real minor number for your
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test module, that would be crazy.
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- The misc device should implement the read and write functions.
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- The misc device node should show up in /dev/eudyptula.
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- When the character device node is read from, your assigned id is
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returned to the caller.
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- When the character device node is written to, the data sent to the
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kernel needs to be checked. If it matches your assigned id, then
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return a correct write return value. If the value does not match
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your assigned id, return the "invalid value" error value.
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- The misc device should be registered when your module is loaded, and
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unregistered when it is unloaded.
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- Provide some "proof" this all works properly.
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As you will be putting your id into the kernel module, of course you
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haven't forgotten it, but just to be safe, it's "[redacted]".
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