clean for kernel build

[Andrew Falanga]

How does one clean the build environment for the kernel?  I'm building
a custom kernel for IPSec and when it got to the linking phase of the
build, the build process bailed with many linking errors:

xform_ah.o(.text+0x15): In function `ah_algorithm_lookup':
: undefined reference to `auth_hash_hmac_sha2_512'
xform_ah.o(.text+0x25): In function `ah_algorithm_lookup':
: undefined reference to `auth_hash_key_md5'
xform_ah.o(.text+0x35): In function `ah_algorithm_lookup':
: undefined reference to `auth_hash_hmac_ripemd_160'
xform_ah.o(.text+0x3f): In function `ah_algorithm_lookup':
: undefined reference to `auth_hash_hmac_sha1'
xform_ah.o(.text+0x4f): In function `ah_algorithm_lookup':
: undefined reference to `auth_hash_hmac_md5'

Many more lines that look very similar to this.  I'm thinking that it
might be something left over from the last time I rebuilt the kernel
(which on this system is when it went from 6.2-RELEASE to
7.0-RELEASE).  So, what make target will clean what I need it to
clean, and are there any other directions similar to what can be found
in the handbook for when rebuilding world?  (This time I don't want to
rebuild world, I just need a new kernel.)

Andy

-- 
 A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?