merge libmaple docs ("leaflabs-docs") into ./docs

In the past, libample documentation was forked out of this repository
because the documentation had increased in scope. For the librambutan,
and the rambutan project in general, we will try to keep documentation
closer to the source code, so the librambutan-specific documentation
should live here. Other sections of leaflabs-docs will be culled in a
following commit.

This merge attempts to maintain history by using a subtree strategy.
Followed directions at:

    http://nuclearsquid.com/writings/subtree-merging-and-you/

Full history for files should be accessible using the "--follow" flag to
git log, eg:

    git log --follow docs/source/adc.rst

It should be possible to pull patches from leaflabs-docs with:

    git pull -s subtree leaflabs-docs master

... at least until the docs in this repository diverge significantly.

1 files changed, 33 insertions, 0 deletions

diff --git a/docs/source/fsmc.rst b/docs/source/fsmc.rst
new file mode 100644
index 0000000..c8f0125
--- /dev/null
+++ b/docs/source/fsmc.rst
@@ -0,0 +1,33 @@
+.. _fsmc:
+
+FSMC
+====
+
+The Flexible Static Memory Controller (FSMC) is a peripheral which an
+be configured to control a variety of external memory chips.
+
+Normally, any variables in your program will be allocated space in RAM
+(notable exceptions are variables marked with ``const`` or
+:ref:`__FLASH__ <arm-gcc-attribute-flash>`).  Without the FSMC, this
+space is limited to the amount that comes built-in to the chip's
+*internal* SRAM.
+
+The addition of the FSMC peripheral allows addtional memory to be
+used.  For example, it is used on the Maple Native to interface with
+the board's built-in external SRAM chip.  However, this extra memory
+comes at a cost: the FSMC uses a fairly large number of GPIOs.
+
+The FSMC peripheral is currently only available on the Maple Native.
+On that board, we have broken out a wide variety of the FSMC lines, so
+that experienced users can add additional external memory chips to
+suit their own applications' purposes.
+
+.. TODO Find some tutorials on SRAM or write one on FSMC, specifically
+.. ones that cover: address, data, chip-select etc. pins, memory bank
+.. organization
+
+Recommended Reading
+-------------------
+
+- Wikipedia article on `SRAM <http://en.wikipedia.org/wiki/Static_random-access_memory>`_
+- :ref:`ST RM0008 <maple-native-b-stdocs>` chapter on FSMC.