Add pin mapping code.

This commit also introduces board directories and moves board
specific config into the appropriate board directory.

boards/stm32f4xx-af.csv was extracted from the STM32F4xx datasheet
and hand-tweaked.

make-pins.py takes boards/stm32f4xx-af.csv, boards/stm32f4xx-prefix.c,
and boards/BOARD-NAME/pins.csv as input and generates the file
build/pins_BOARD_NAME.c

The generated pin file for PYBOARD4 looks like this:
https://gist.github.com/dhylands/9063231

The generated pins file includes all of the supported alternate
functions, and includes upsupported alternate functions as comments.

See the commnet block at the top of stm/pin_map.c for details on
how to use the pin mapper.

I also went ahead and modified stm/gpio.c to use the pin mapper.

2 files changed, 14 insertions, 8 deletions

diff --git a/py/objfun.c b/py/objfun.c
index 354d7ff9ca..7c89c47000 100644
--- a/py/objfun.c
+++ b/py/objfun.c
@@ -26,26 +26,30 @@
 // mp_obj_fun_native_t defined in obj.h
 
 STATIC void check_nargs(mp_obj_fun_native_t *self, int n_args, int n_kw) {
-    if (n_kw && !self->is_kw) {
+    rt_check_nargs(n_args, self->n_args_min, self->n_args_max, n_kw, self->is_kw);
+}
+
+void rt_check_nargs(int n_args, machine_uint_t n_args_min, machine_uint_t n_args_max, int n_kw, bool is_kw) {
+    if (n_kw && !is_kw) {
         nlr_jump(mp_obj_new_exception_msg(&mp_type_TypeError,
                                           "function does not take keyword arguments"));
     }
 
-    if (self->n_args_min == self->n_args_max) {
-        if (n_args != self->n_args_min) {
+    if (n_args_min == n_args_max) {
+        if (n_args != n_args_min) {
             nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                                                      "function takes %d positional arguments but %d were given",
-                                                     self->n_args_min, n_args));
+                                                     n_args_min, n_args));
         }
     } else {
-        if (n_args < self->n_args_min) {
+        if (n_args < n_args_min) {
             nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                                                     "<fun name>() missing %d required positional arguments: <list of names of params>",
-                                                    self->n_args_min - n_args));
-        } else if (n_args > self->n_args_max) {
+                                                    n_args_min - n_args));
+        } else if (n_args > n_args_max) {
             nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                                                      "<fun name> expected at most %d arguments, got %d",
-                                                     self->n_args_max, n_args));
+                                                     n_args_max, n_args));
         }
     }
 }
diff --git a/py/runtime.h b/py/runtime.h
index 1eef99d2ff..7215cc8890 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -1,3 +1,5 @@
+void rt_check_nargs(int n_args, machine_uint_t n_args_min, machine_uint_t n_args_max, int n_kw, bool is_kw);
+
 int rt_is_true(mp_obj_t arg);
 
 mp_obj_t rt_load_const_dec(qstr qstr);