3ds: 3ds port sources. First set of two

This commit adds changes to the original rockbox sources.

Note: the port files, functions, folders, etc., will be referred
to as 'ctru' to avoid using the Nintendo name elsewhere.

Change-Id: I0e2d3d4d2a75bd45ea67dc3452eb8d5487cf1f5a

firmware/kernel/include/thread.h

@@ -89,7 +89,7 @@ struct thread_entry;
  *
  * simulator (possibly) doesn't simulate stack usage anyway but well ... */
 
-#if defined(HAVE_SDL_THREADS) || defined(__PCTOOL__)
+#if defined(HAVE_SDL_THREADS) || defined(__PCTOOL__) || defined(CTRU)
 #define DEFAULT_STACK_SIZE 0x100 /* tiny, ignored anyway */
 #else
 #include "asm/thread.h"

firmware/kernel/mutex.c

@@ -75,11 +75,15 @@ void mutex_lock(struct mutex *m)
 /* Release ownership of a mutex object - only owning thread must call this */
 void mutex_unlock(struct mutex *m)
 {
+#ifndef CTRU
+    /* FIXME: synchronization primitives does not behave
+       correctly between different cores */
     /* unlocker not being the owner is an unlocking violation */
     KERNEL_ASSERT(m->blocker.thread == __running_self_entry(),
                   "mutex_unlock->wrong thread (%s != %s)\n",
                   m->blocker.thread->name,
                   __running_self_entry()->name);
+#endif
 
     if(m->recursion > 0)
     {

firmware/kernel/thread-common.c

@@ -304,7 +304,7 @@ int thread_get_debug_info(unsigned int thread_id,
 #ifdef HAVE_SCHEDULER_BOOSTCTRL
         cpu_boost = thread->cpu_boost;
 #endif
-#ifndef HAVE_SDL_THREADS
+#if !defined(HAVE_SDL_THREADS) && !defined(CTRU)
         infop->stack_usage = stack_usage(thread->stack, thread->stack_size);
 
         size_t stack_used_current =

firmware/kernel/thread-internal.h

@@ -32,7 +32,7 @@
  *
  * simulator (possibly) doesn't simulate stack usage anyway but well ... */
 
-#if defined(HAVE_SDL_THREADS) || defined(__PCTOOL__)
+#if defined(HAVE_SDL_THREADS) || defined(__PCTOOL__) || defined(CTRU)
 struct regs
 {
     void *t;             /* OS thread */