The kernel module em87 performs or emulates hardware floating-point operations. Whether it performs the operations or emulates them depends whether your computer contains a mathematics co-processor. Note that the Intel 80486-DX processor has the co-processor built in.
em87 is called a kernel module because you can link it into the kernel or exclude it from the kernel, just like a device driver. However, it is not a true device driver because it does not perform I/O from a peripheral device. To install em87 into a kernel (should your kernel not already contain it), log in as the superuser root and execute the following commands:
cd /etc/conf
em87/mkdev
bin/idmkcoh -o /_k_e_r_n_e_l___n_a_m_e
where kernel_name is the name of the new kernel to build. When you next boot COHERENT, hardware floating point will be enabled.