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+libtfm
+======
+
+This is a trivial port of the Tom's Fast Math (TFM) bignum library to
+the Cryptech environment.  At least for now, this just checks the
+package out from GitHub, verifies that the SHA-256 digest of the
+commit we're using matches a known value, and builds the library with
+the options we want.
+
+See tomsfastmath/doc/tfm.pdf for API details.
+
+In theory, the need for most (perhaps all) of this will go away when
+more of the bignum math is implemented in Verilog.  Part of the reason
+for using the TFM library is that its extremely modular structure make
+it easy for us to link in only the functions we need.