WIP: Switch to LuaJIT

Config.mk

@@ -99,3 +99,6 @@ INIHHOME=$(realpath external/inih)
 
 LUAHOME=$(realpath external/lua)
 LUALIB=$(LUAHOME)/liblua.a
+
+LUAJITHOME=$(realpath external/luajit)
+LUAJITLIB=$(LUAJITHOME)/src/libluajit.a

Kernel.mk

@@ -85,8 +85,8 @@ INCLUDE		+=	-I $(FLUIDSYNTHBUILDDIR)/include \
 			-I $(FLUIDSYNTHHOME)/include
 EXTRALIBS	+=	$(FLUIDSYNTHLIB)
 
-INCLUDE		+=	-I $(LUAHOME)
-EXTRALIBS	+=	$(LUALIB)
+INCLUDE		+=	-I $(LUAJITHOME)/src
+EXTRALIBS	+=	$(LUAJITLIB)
 
 #
 # Generate version string from git tag

Makefile

@@ -147,10 +147,20 @@ $(LUAHOME)/liblua.a:
 	CFLAGS="$(CFLAGS_EXTERNAL) \$$(MYCFLAGS) -Wall -Werror -O3 -fno-stack-protector -fno-common" \
 	MYCFLAGS="\$$(LOCAL)"
 
+luajit: $(LUAJITLIB)
+
+$(LUAJITLIB):
+	@${APPLY_PATCH} $(LUAJITHOME) patches/luajit-2.1-circle.patch
+
+	$(MAKE) -C $(LUAJITHOME)/src \
+	CROSS="$(PREFIX)" \
+	XCFLAGS="-DLJ_TARGET_BAREMETAL -DLUAJIT_USE_SYSMALLOC=1 -DLUAJIT_DISABLE_PROFILE=1 -DLUAJIT_SECURITY_PRNG=0" \
+	libluajit.a
+
 #
 # Build kernel itself
 #
-all: circle-stdlib mt32emu fluidsynth lua
+all: circle-stdlib mt32emu fluidsynth lua luajit
 	@$(MAKE) -f Kernel.mk $(KERNEL).img $(KERNEL).hex
 
 #
@@ -169,6 +179,7 @@ mrproper: clean
 	@${REVERSE_PATCH} $(CIRCLEHOME) patches/circle-45-minimal-usb-drivers.patch
 	@${REVERSE_PATCH} $(FLUIDSYNTHHOME) patches/fluidsynth-2.3.1-circle.patch
 	@${REVERSE_PATCH} $(LUAHOME) patches/lua-5.4.4-circle.patch
+	@${REVERSE_PATCH} $(LUAJITHOME) patches/luajit-2.1-circle.patch
 
 # Clean circle-stdlib
 	@if [ -f $(CIRCLE_STDLIB_CONFIG) ]; then $(MAKE) -C $(CIRCLESTDLIBHOME) mrproper; fi
@@ -182,3 +193,6 @@ mrproper: clean
 
 # Clean Lua
 	@$(MAKE) -C $(LUAHOME) clean
+
+# Clean LuaJIT
+	@$(MAKE) -C $(LUAJITHOME) clean

patches/luajit-2.1-circle.patch

@@ -0,0 +1,29 @@
+diff --git a/src/lj_mcode.c b/src/lj_mcode.c
+index 163aada4..c456da00 100644
+--- a/src/lj_mcode.c
++++ b/src/lj_mcode.c
+@@ -124,6 +124,24 @@ static int mcode_setprot(void *p, size_t sz, int prot)
+   return mprotect(p, sz, prot);
+ }
+
++#elif LJ_TARGET_BAREMETAL
++#define MCPROT_RW	(1 << 0)
++#define MCPROT_RX	(1 << 1)
++#define MCPROT_RWX	(1 << 2)
++
++static void *mcode_alloc_at(jit_State *J, uintptr_t hint, size_t sz, int prot)
++{
++	return NULL;
++}
++
++static void mcode_free(jit_State *J, void *p, size_t sz)
++{
++}
++
++static int mcode_setprot(void *p, size_t sz, int prot)
++{
++  return 0;
++}
+ #else
+
+ #error "Missing OS support for explicit placement of executable memory"

src/mt32pi.cpp

@@ -468,7 +468,9 @@ void CMT32Pi::MainTask()
 		// Run scripting engine tasks
 		if (m_pLuaState)
 		{
-			if (lua_getglobal(m_pLuaState, "OnUpdate") != LUA_TFUNCTION)
+			lua_getglobal(m_pLuaState, "OnMIDISysExMessage");
+
+			if (!lua_isfunction(m_pLuaState, 1))
 				lua_pop(m_pLuaState, 1);
 			else
 			{
@@ -700,7 +702,9 @@ void CMT32Pi::OnShortMessage(u32 nMessage)
 		const int nStackSize = lua_gettop(m_pLuaState);
 
 		// Ensure function exists
-		if (lua_getglobal(m_pLuaState, "OnMIDIShortMessage") != LUA_TFUNCTION)
+		lua_getglobal(m_pLuaState, "OnMIDIShortMessage");
+
+		if (!lua_isfunction(m_pLuaState, 1))
 			lua_pop(m_pLuaState, 1);
 		else
 		{
@@ -756,7 +760,9 @@ void CMT32Pi::OnSysExMessage(const u8* pData, size_t nSize)
 	if (m_pLuaState)
 	{
 		// Ensure function exists
-		if (lua_getglobal(m_pLuaState, "OnMIDISysExMessage") != LUA_TFUNCTION)
+		lua_getglobal(m_pLuaState, "OnMIDISysExMessage");
+
+		if (!lua_isfunction(m_pLuaState, 1))
 			lua_pop(m_pLuaState, 1);
 		else
 		{