4 files changed, 103 insertions, 0 deletions
diff --git a/arm9/lib/libc/Makefile b/arm9/lib/libc/Makefile
new file mode 100644
index 00000000..5a993851
--- /dev/null
+++ b/arm9/lib/libc/Makefile
@@ -0,0 +1,80 @@
+# Try to include devkitarm if installed
+TOOLCHAIN := $(DEVKITARM)
+
+ifneq (,$(wildcard $(TOOLCHAIN)/base_tools))
+include $(TOOLCHAIN)/base_tools
+endif
+
+# If you are using WSL, it is recommended you build with NOWINE=1.
+WSLENV ?= no
+ifeq ($(WSLENV),)
+NOWINE = 1
+else
+NOWINE = 0
+endif
+
+ifeq ($(OS),Windows_NT)
+EXE := .exe
+WINE :=
+else
+EXE :=
+WINE := wine
+endif
+
+ifeq ($(NOWINE),1)
+WINE :=
+endif
+
+# Compare result of arm9, arm7, and ROM to sha1 hash(s)
+COMPARE ?= 1
+
+##################### Compiler Options #######################
+
+MWCCVERSION = 2.0/sp1
+
+CROSS   := arm-none-eabi-
+
+MWCCARM  = ../../../tools/mwccarm/$(MWCCVERSION)/mwccarm.exe
+# Argh... due to EABI version shenanigans, we can't use GNU LD to link together
+# MWCC built objects and GNU built ones. mwldarm, however, doesn't care, so we
+# have to use mwldarm for now.
+# TODO: Is there a hack workaround to let us go back to GNU LD? Ideally, the
+# only dependency should be MWCCARM.
+MWLDARM  = ../../../tools/mwccarm/$(MWCCVERSION)/mwldarm.exe
+MWASMARM = ../../../tools/mwccarm/$(MWCCVERSION)/mwasmarm.exe
+SCANINC = ../../../tools/scaninc/scaninc$(EXE)
+
+AS      = $(WINE) $(MWASMARM)
+CC      = $(WINE) $(MWCCARM)
+CPP     := cpp -P
+LD      = $(WINE) $(MWLDARM)
+AR      := $(CROSS)ar
+OBJDUMP := $(CROSS)objdump
+OBJCOPY := $(CROSS)objcopy
+
+# ./tools/mwccarm/2.0/base/mwasmarm.exe -proc arm5te asm/arm9_thumb.s -o arm9.o
+ASFLAGS = -proc arm5te -ir ../../..
+CFLAGS = -O4,p -proc arm946e -fp soft -lang c99 -i include -ir include-mw -ir arm9/lib/libc/include -ir arm9/lib/libnns/include -ir arm9/lib/NitroSDK/include -W all
+LDFLAGS = -library -nodead -w off -proc v5te -interworking -pic
+ARFLAGS = rcS
+
+export MWCIncludes := include
+
+################ Targets #################
+
+.PHONY: all clean
+
+all:
+	@:
+
+clean:
+	$(RM) $(%.a=%/*.o)
+
+%.a:
+	$(AR) $(ARFLAGS) -o $@ $^
+
+%.o: %.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+%.o: %.s
+	$(AS) $(ASFLAGS) -o $@ $<
diff --git a/arm9/lib/libc/include/MSL.h b/arm9/lib/libc/include/MSL.h
new file mode 100644
index 00000000..a1709bc4
--- /dev/null
+++ b/arm9/lib/libc/include/MSL.h
@@ -0,0 +1,8 @@
+#ifndef MSL_H
+#define MSL_H
+
+//include all msl files here
+
+#include "MSL_Common_arith.h"
+
+#endif //MSL_H
diff --git a/arm9/lib/libc/include/MSL_Common_arith.h b/arm9/lib/libc/include/MSL_Common_arith.h
new file mode 100644
index 00000000..3ec6bdbc
--- /dev/null
+++ b/arm9/lib/libc/include/MSL_Common_arith.h
@@ -0,0 +1,8 @@
+#ifndef MSL_COMMON_ARITH_H
+#define MSL_COMMON_ARITH_H
+
+#include "nitro/types.h"
+
+s32 abs(s32 val);
+
+#endif //MSL_COMMON_ARITH_H
diff --git a/arm9/lib/libc/src/MSL_Common_arith.c b/arm9/lib/libc/src/MSL_Common_arith.c
new file mode 100644
index 00000000..d4a2e834
--- /dev/null
+++ b/arm9/lib/libc/src/MSL_Common_arith.c
@@ -0,0 +1,7 @@
+#include "MSL_Common_arith.h"
+#include "function_target.h"
+
+ARM_FUNC s32 abs(s32 val)
+{
+    return val < 0 ? -val : val;
+}