Implement devkitARM/newlib lock support & dynamic reent

libctru/include/3ds/synchronization.h

@@ -3,17 +3,13 @@
  * @brief Provides synchronization locks.
  */
 #pragma once
+#include <sys/lock.h>
 
 /// A light lock.
-typedef s32 LightLock;
+typedef _LOCK_T LightLock;
 
 /// A recursive lock.
-typedef struct
-{
-	LightLock lock; ///< Inner light lock.
-	u32 thread_tag; ///< Tag of the thread that currently has the lock.
-	u32 counter;    ///< Lock count.
-} RecursiveLock;
+typedef _LOCK_RECURSIVE_T RecursiveLock;
 
 /// Performs a Data Synchronization Barrier operation.
 static inline void __dsb(void)

libctru/source/internal.h

@@ -4,10 +4,15 @@
 #include <3ds/svc.h>
 #include <sys/reent.h>
 
+#define THREADVARS_MAGIC  0x21545624 // !TV$
 #define FS_OVERRIDE_MAGIC 0x21465324 // !FS$
 
+// Keep this structure under 0x80 bytes
 typedef struct
 {
+	// Magic value used to check if the struct is initialized
+	u32 magic;
+
 	// Pointer to this thread's newlib state
 	struct _reent* reent;
 

libctru/source/system/allocateHeaps.c

@@ -11,7 +11,7 @@ u32 __ctru_heap_size;
 u32 __ctru_linear_heap;
 u32 __ctru_linear_heap_size;
 
-void __attribute__((weak)) __system_allocateHeaps() {
+void __attribute__((weak)) __system_allocateHeaps(void) {
 	u32 tmp=0;
 
 	if(envIsHomebrew()) {

libctru/source/system/appExit.c

@@ -6,7 +6,7 @@
 #include <3ds/services/fs.h>
 #include <3ds/services/hid.h>
 
-void __attribute__((weak)) __appExit() {
+void __attribute__((weak)) __appExit(void) {
 	// Exit services
 	sdmcExit();
 	fsExit();

libctru/source/system/appInit.c

@@ -6,7 +6,7 @@
 #include <3ds/services/fs.h>
 #include <3ds/services/hid.h>
 
-void __attribute__((weak)) __appInit() {
+void __attribute__((weak)) __appInit(void) {
 	// Initialize services
 	srvInit();
 	aptInit();

libctru/source/system/initArgv.c

@@ -10,7 +10,7 @@ char** __system_argv;
 extern char* fake_heap_start;
 extern char* fake_heap_end;
 
-void __system_initArgv()
+void __system_initArgv(void)
 {
 	int i;
 	const char* arglist = envGetSystemArgList();

libctru/source/system/initSystem.c

@@ -8,31 +8,27 @@
 
 void (*__system_retAddr)(void);
 
-void __system_allocateHeaps();
-void __system_initArgv();
-void __appInit();
+void __system_initSyscalls(void);
+void __system_allocateHeaps(void);
+void __system_initArgv(void);
+void __appInit(void);
 
-
-void __ctru_exit(int rc);
-int __libctru_gtod(struct _reent *ptr, struct timeval *tp, struct timezone *tz);
-
-Result __sync_init(void) __attribute__((weak));
+Result __sync_init(void);
 
 void __attribute__((weak)) __libctru_init(void (*retAddr)(void))
 {
-
-	// Register newlib exit() syscall
-	__syscalls.exit = __ctru_exit;
-    __syscalls.gettod_r = __libctru_gtod;
-
+	// Store the return address
 	__system_retAddr = envIsHomebrew() ? retAddr : NULL;
 
-	if (__sync_init)
+	// Initialize the synchronization subsystem
 	__sync_init();
 
+	// Initialize newlib support system calls
+	__system_initSyscalls();
+
+	// Allocate application and linear heaps
 	__system_allocateHeaps();
 
 	// Build argc/argv if present
 	__system_initArgv();
-
 }

libctru/source/system/syscalls.c

@@ -0,0 +1,48 @@
+#include <sys/iosupport.h>
+#include <sys/time.h>
+#include <sys/lock.h>
+#include <sys/reent.h>
+#include <string.h>
+
+#include <3ds/types.h>
+#include <3ds/svc.h>
+#include <3ds/env.h>
+#include <3ds/synchronization.h>
+#include "../internal.h"
+
+void __ctru_exit(int rc);
+int __libctru_gtod(struct _reent *ptr, struct timeval *tp, struct timezone *tz);
+
+static struct _reent* __ctru_get_reent()
+{
+	ThreadVars* tv = getThreadVars();
+	if (tv->magic != THREADVARS_MAGIC)
+	{
+		svcBreak(USERBREAK_PANIC);
+		for (;;);
+	}
+	return tv->reent;
+}
+
+void __system_initSyscalls(void)
+{
+	// Register newlib syscalls
+	__syscalls.exit     = __ctru_exit;
+	__syscalls.gettod_r = __libctru_gtod;
+	__syscalls.getreent = __ctru_get_reent;
+
+	// Register locking syscalls
+	__syscalls.lock_init                  = LightLock_Init;
+	__syscalls.lock_acquire               = LightLock_Lock;
+	__syscalls.lock_try_acquire           = LightLock_TryLock;
+	__syscalls.lock_release               = LightLock_Unlock;
+	__syscalls.lock_init_recursive        = RecursiveLock_Init;
+	__syscalls.lock_acquire_recursive     = RecursiveLock_Lock;
+	__syscalls.lock_try_acquire_recursive = RecursiveLock_TryLock;
+	__syscalls.lock_release_recursive     = RecursiveLock_Unlock;
+
+	// Initialize thread vars for the main thread
+	ThreadVars* tv = getThreadVars();
+	tv->magic = THREADVARS_MAGIC;
+	tv->reent = _impure_ptr;
+}