Merge #13372: doc: split FreeBSD build instructions out of build-unix.md

1e4eec47beb5d910b99f4c062fa4388337106d14 doc: split FreeBSD build instructions out of build-unix.md (steverusso)

Pull request description:

  I've found that the instructions for how to build on FreeBSD are difficult to find. (They are located at the very bottom of the `build-unix.md` guide.)

  In the beginning of the `build-unix.md` guide, there is a list for "BSD specific instructions" which has links to the `build-netbsd.md` and `build-openbsd.md` guides. I figured that the FreeBSD build instructions should be linked to as well in that list which would make them easier to discover.

  (I also think the argument could be made to separate out the FreeBSD build instructions into a `build-freebsd.md` guide, which I'd be happy to do, but I'll leave that for discussion.)

Tree-SHA512: 02d7939778ae2b9a4ef8f053ff296455be05023c1c557dcc25a963eb829d84524bd34d39e6863f2e68b655832194d38bffec3286106588ae32f006686a1b36a9

2 files changed, 47 insertions, 32 deletions

diff --git a/doc/build-freebsd.md b/doc/build-freebsd.md
new file mode 100644
index 0000000000..c2e4e36dff
--- /dev/null
+++ b/doc/build-freebsd.md
@@ -0,0 +1,46 @@
+FreeBSD build guide
+======================
+(updated for FreeBSD 11.1)
+
+This guide describes how to build bitcoind and command-line utilities on FreeBSD.
+
+This guide does not contain instructions for building the GUI.
+
+## Preparation
+
+You will need the following dependencies, which can be installed as root via pkg:
+
+```
+pkg install autoconf automake boost-libs git gmake libevent libtool openssl pkgconf
+```
+
+For the wallet (optional):
+```
+./contrib/install_db4.sh `pwd`
+export BDB_PREFIX='$PWD/db4'
+```
+
+See [dependencies.md](dependencies.md) for a complete overview.
+
+Download the source code:
+```
+git clone https://github.com/bitcoin/bitcoin
+```
+
+## Building Bitcoin Core
+
+**Important**: Use `gmake` (the non-GNU `make` will exit with an error).
+
+```
+./autogen.sh
+
+./configure                  # to build with wallet OR
+./configure --disable-wallet # to build without wallet
+
+gmake
+```
+
+*Note on debugging*: The version of `gdb` installed by default is [ancient and considered harmful](https://wiki.freebsd.org/GdbRetirement).
+It is not suitable for debugging a multi-threaded C++ program, not even for getting backtraces. Please install the package `gdb` and
+use the versioned gdb command (e.g. `gdb7111`).
+
diff --git a/doc/build-unix.md b/doc/build-unix.md
index 2d10484a65..60d888a297 100644
--- a/doc/build-unix.md
+++ b/doc/build-unix.md
@@ -2,8 +2,7 @@ UNIX BUILD NOTES
 ====================
 Some notes on how to build Bitcoin Core in Unix.
 
-(For BSD specific instructions, see [build-openbsd.md](build-openbsd.md) and/or
-[build-netbsd.md](build-netbsd.md))
+(For BSD specific instructions, see `build-*bsd.md` in this directory.)
 
 Note
 ---------------------
@@ -303,33 +302,3 @@ To build executables for ARM:
 
 For further documentation on the depends system see [README.md](../depends/README.md) in the depends directory.
 
-Building on FreeBSD
---------------------
-
-(Updated as of FreeBSD 11.0)
-
-Clang is installed by default as `cc` compiler, this makes it easier to get
-started than on [OpenBSD](build-openbsd.md). Installing dependencies:
-
-    pkg install autoconf automake libtool pkgconf
-    pkg install boost-libs openssl libevent
-    pkg install gmake
-
-You need to use GNU make (`gmake`) instead of `make`.
-(`libressl` instead of `openssl` will also work)
-
-For the wallet (optional):
-
-    ./contrib/install_db4.sh `pwd`
-    setenv BDB_PREFIX $PWD/db4
-
-Then build using:
-
-    ./autogen.sh
-    ./configure --disable-wallet # OR
-    ./configure BDB_CFLAGS="-I${BDB_PREFIX}/include" BDB_LIBS="-L${BDB_PREFIX}/lib -ldb_cxx"
-    gmake
-
-*Note on debugging*: The version of `gdb` installed by default is [ancient and considered harmful](https://wiki.freebsd.org/GdbRetirement).
-It is not suitable for debugging a multi-threaded C++ program, not even for getting backtraces. Please install the package `gdb` and
-use the versioned gdb command e.g. `gdb7111`.