Usage of kern_* functions in kernel

[Marc Lörner]

Hello,
I googled but found nothing about the usage of the kern_* functions 
(kern_open, kern_close, kern_pwritev, kern_preadv) that are located in 
vfs_syscalls.c

When I use kern_open to open a file within the kernel, I get an error. 
When I use the normal vn_open function instead, all works well.

So my question is which functions are recommended by you kernel-hackers 
for use within kernelspace?

And here a second question: Is it possible to open/use the console driver in 
kernelspace within the functions mentioned above? 
If not, can you give me some pointers on where I can find this information!

Regards,
Marc