These are the userspace tools required for bcache.

Bcache is a patch for the Linux kernel to use SSDs
to cache other block devices. For more information, see
http://bcache.evilpiepirate.org. Documentation for the run time
interface is included in the kernel tree, in Documentation/bcache.txt.

Included:

make-bcache
Formats a block device for use with bcache. A device can be
formatted for use as a cache or as a backing device (requires yet
to be implemented kernel support). The most important option is for
specifying the bucket size. Allocation is done in terms of buckets,
and cache hits are counted per bucket; thus a smaller bucket size
will give better cache utilization, but poorer write performance. The
bucket size is intended to be equal to the size of your SSD's erase
blocks, which seems to be 128k-512k for most SSDs; feel free to
experiment.

bcache-super-show
Prints the bcache superblock of a cache device or a backing device.

Udev rules
The first half of the rules do auto-assembly and add uuid symlinks
to cache and backing devices. If util-linux's libblkid is
sufficiently recent (2.24) the rules will take advantage of
the fact that bcache has already been detected. Otherwise
they call a small probe-bcache program that imitates blkid.

The second half of the rules add symlinks to cached devices,
which are the devices created by the bcache kernel module.

Initramfs support
Currently initramfs-tools, mkinitcpio and dracut are supported.