ports: Make new ports/ sub-directory and move all ports there.

This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.

ports/stm32/mpthreadport.c

@@ -0,0 +1,94 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+
+#include "py/mpconfig.h"
+#include "py/mpstate.h"
+#include "py/gc.h"
+#include "py/mpthread.h"
+#include "gccollect.h"
+
+#if MICROPY_PY_THREAD
+
+// the mutex controls access to the linked list
+STATIC mp_thread_mutex_t thread_mutex;
+
+void mp_thread_init(void) {
+    mp_thread_mutex_init(&thread_mutex);
+    mp_thread_set_state(&mp_state_ctx.thread);
+}
+
+void mp_thread_gc_others(void) {
+    mp_thread_mutex_lock(&thread_mutex, 1);
+    for (pyb_thread_t *th = pyb_thread_all; th != NULL; th = th->all_next) {
+        gc_collect_root((void**)&th, 1);
+        gc_collect_root(&th->arg, 1);
+        gc_collect_root(&th->stack, 1);
+        if (th != pyb_thread_cur) {
+            gc_collect_root(th->stack, th->stack_len);
+        }
+    }
+    mp_thread_mutex_unlock(&thread_mutex);
+}
+
+void mp_thread_create(void *(*entry)(void*), void *arg, size_t *stack_size) {
+    if (*stack_size == 0) {
+        *stack_size = 4096; // default stack size
+    } else if (*stack_size < 2048) {
+        *stack_size = 2048; // minimum stack size
+    }
+
+    // round stack size to a multiple of the word size
+    size_t stack_len = *stack_size / sizeof(uint32_t);
+    *stack_size = stack_len * sizeof(uint32_t);
+
+    // allocate stack and linked-list node (must be done outside thread_mutex lock)
+    uint32_t *stack = m_new(uint32_t, stack_len);
+    pyb_thread_t *th = m_new_obj(pyb_thread_t);
+
+    mp_thread_mutex_lock(&thread_mutex, 1);
+
+    // create thread
+    uint32_t id = pyb_thread_new(th, stack, stack_len, entry, arg);
+    if (id == 0) {
+        mp_thread_mutex_unlock(&thread_mutex);
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "can't create thread"));
+    }
+
+    mp_thread_mutex_unlock(&thread_mutex);
+
+    // adjust stack_size to provide room to recover from hitting the limit
+    *stack_size -= 1024;
+}
+
+void mp_thread_start(void) {
+}
+
+void mp_thread_finish(void) {
+}
+
+#endif // MICROPY_PY_THREAD