Re: compat code function pointers

[Brian Buhrow <buhrow%nfbcal.org@localhost>]

	hello.  I like the compat.* filenames as I think they're more
descriptive than the junk names.  If the contents of these files is just
for device links, you might even use:
kern_devcompat.*, which is even more descriptive.

Just my 2 cents.
-thanks
-Brian

On Mar 18,  9:00pm, Christos Zoulas wrote:
} Subject: compat code function pointers
} 
} Hi,
} 
} Paul and I have been working towards separating the compat code from the
} main kernel and eliminating all the COMPAT_XX ifdefs. This will allow
} the compat modules to work properly even if the kernel is not compiled
} with the compat options.
} 
} The general approach to this is to move all the compat code out of the
} main kernel leaving behind function pointers that typically point to
} noops (enosys) that the compat code can then repoint to the compat code
} functions when it loads (and re-point them to noops when it unloads).
} 
} The question came up where to store the function pointers for device
} drivers that are not always present in the kernel. We could use weak
} references in the compat code so that the code links, but the kernel
} linker does not currently support weak pointers. Another alternative
} is to create a file in the kernel that contains those function pointers.
} 
} Paul suggested:
} 
} 	src/sys/kern/kern_junk.c
} 	src/sys/sys/kern_junk.h
} 
} I suggested:
} 
} 	src/sys/kern/kern_compat.c
} 	src/sys/sys/compat.h
} 
} Opinions?
} 
} christos
>-- End of excerpt from Christos Zoulas