kfreebsd-headers-8-486 software package provides header files for kernel of FreeBSD 9 (meta-package), you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install kfreebsd-headers-8-486
kfreebsd-headers-8-486 is installed in your system.
Make ensure the kfreebsd-headers-8-486 package were installed using the commands given below,
$ sudo dpkg-query -l | grep kfreebsd-headers-8-486 *
You will get with kfreebsd-headers-8-486 package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Kernels |
| Package | kfreebsd-headers-8-486 |
| Version | 8.3-6+deb7u1 |
| Description | header files for kernel of FreeBSD 9 (meta-package) |
| Sub Section | Kernels |