From owner-freebsd-hackers  Sun Dec  2 17:53:35 2001
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References: <000601c17b6b$7a89c190$037d6041@gandalf>   <200112030128.fB31S0M62172@harmony.village.org>
Subject: Re: device object, driver object, cdevsw 
Date: Sun, 2 Dec 2001 20:42:00 -0500
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I am using stable not devfs for development.

In the Design and Implementation of the 4.4 BSD Operating System. Chapter 6
states

Device Drivers

A device is divided into three main sections
1. Autoconfiguration and initialization routines
2. Routines for servicing I/O requests (the top half)
3. Interrupt service routines (the bottom half)

Would it be a fair analogy to say the KLD portion of the code equates to 1.,
the cdevsw equate to 2., and the isr equate to 3.

I appreciate your response I'm just trying to get a thorough understanding.

Thank you in advance,


>
> :
> : Would it be fair to say the KLD components represent the dynamics kernel
> : facilities and the cdevsw implments what we consider the "traditional"
Unix
> : device driver. Could somebody shed light on this subject.
>
> The matter is actually fairly simple.
>
> Your make_dev() calls assocaite the cdevsw to use with the device
> nodes you create (which also must be created using mknod in -stable or
> current w/o devfs).
>
> Typically, you won't have to worry too much about the link between the
> two.  It just happens.
>
the message


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