lib: Add initial libc stub

Signed-off-by: Ian Moffett <ian@osmora.org>

5 files changed, 80 insertions, 0 deletions

diff --git a/src/lib/Makefile b/src/lib/Makefile
new file mode 100644
index 0000000..1febd2e
--- /dev/null
+++ b/src/lib/Makefile
@@ -0,0 +1,10 @@
+LDSCRIPT=../../sys/arch/$(TARGET)/conf/user.ld
+
+.PHONY: all
+all:
+	cd libc//; LDSCRIPT=$(LDSCRIPT) CC=$(CC) ASM=$(ASM) \
+		      LD=$(ASM) SYSROOT=$(SYSROOT) make
+
+.PHONY: clean
+clean:
+	cd libc/; make clean
diff --git a/src/lib/libc/Makefile b/src/lib/libc/Makefile
new file mode 100644
index 0000000..3287084
--- /dev/null
+++ b/src/lib/libc/Makefile
@@ -0,0 +1,18 @@
+OBJ = $(shell find build/ -name "*.o")
+LIBC_OUT = libc.a
+
+.PHONY: all
+all: build target
+	ar rcs $(LIBC_OUT) $(OBJ)
+
+.PHONY: target
+target:
+	cd $(TARGET); make CC=$(CC) LD=$(LD) AS=$(AS)
+
+# Create build directory
+build:
+	mkdir -p $@
+
+.PHONY: clean
+clean:
+	rm -rf build/
diff --git a/src/lib/libc/amd64/Makefile b/src/lib/libc/amd64/Makefile
new file mode 100644
index 0000000..f70def3
--- /dev/null
+++ b/src/lib/libc/amd64/Makefile
@@ -0,0 +1,19 @@
+.SILENT:
+override PROMPT := printf "%s\t\t%s\n"
+
+ASMFILES = $(shell find . -name "*.S")
+ASMOBJECTS = $(ASMFILES:.S=.S.o)
+
+.PHONY: all
+all: ../build/$(OBJECTS) ../build/$(ASMOBJECTS)
+
+-include $(DEPS)
+../build/%.o: %.c
+	mkdir -p $(@D)
+	$(CC) -c $(CFLAGS) $< -o $@
+
+-include $(ASMDEPS)
+../build/%.S.o: %.S
+	mkdir -p $(@D)
+	$(PROMPT) " MD.AS " $<
+	$(CC) -c $< -o $@ $(CFLAGS) $(MD_CFLAGS)
diff --git a/src/lib/libc/amd64/crt/crt0.S b/src/lib/libc/amd64/crt/crt0.S
new file mode 100644
index 0000000..71a00e9
--- /dev/null
+++ b/src/lib/libc/amd64/crt/crt0.S
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+    .text
+    .globl _start
+_start:
+    jmp .
diff --git a/src/lib/libc/libc.a b/src/lib/libc/libc.a
new file mode 100644
index 0000000..b45f3f9
--- /dev/null
+++ b/src/lib/libc/libc.a