Updated the instructions for FreeBSD systems.

README.md

@@ -32,8 +32,14 @@ git submodule update --init --recursive
 
 mkdir ./build && cd ./build
 
-# Setup to build newlib.
-./configure --prefix=/usr/local/
+# Create needed dir for the output.
+mkdir /usr/local/riscv && chmod -R 0775 /usr/local/riscv
+
+# Setup to build newlib for 32bit embedded and compressed cpus.
+./configure --prefix=/usr/local/riscv --with-arch=rv32ec \
+    --with-arch=rv32ec \
+    --with-abi=ilp32e \
+    --with-multilib
 make -j4 newlib
 
 # Some Example options below.