$HOME/src is where I put the code in this example. You can pick wherever you like.
$ cd $HOME/src$ git clone https://boringssl.googlesource.com/boringssl$ cd boringssl$ mkdir build$ cd build$ cmake ..$ make
In the boringssl source tree root, make sure there's a
lib and an
include dir. The
lib dir should contain the two libs (I made them symlinks into the build dir). The
include dir is already present by default. Make and populate
lib like this (commands issued in the source tree root, not in the
$ mkdir lib$ cd lib$ ln -s ../build/ssl/libssl.a$ ln -s ../build/crypto/libcrypto.a
LIBS=-lpthread ./configure --with-ssl=$HOME/src/boringssl (where I point out the root of the boringssl tree)
Verify that at the end of the configuration, it says it detected BoringSSL to be used.
make in the curl source tree.
Now you can install curl normally with
make install etc.