3 files changed, 159 insertions, 0 deletions
diff --git a/src/libc/rules.mk b/src/libc/rules.mk
new file mode 100644
index 0000000..34e0912
--- /dev/null
+++ b/src/libc/rules.mk
@@ -0,0 +1,20 @@
+include share/push.mk
+
+# Iterate through subdirectory tree
+
+# Local sources
+SRCS_$(d) := $(wildcard $(d)/*.c)
+LIBS_$(d) := $(d)/libc_n.a
+BINS_$(d) :=
+
+include share/paths.mk
+
+# Local rules
+$(LIBS_$(d)): TCFLAGS = -ffreestanding -fno-builtin -nostdlib
+$(LIBS_$(d)): $(OBJS_$(d))
+	$(ARCHIVE)
+
+$(BINS_$(d)): $(OBJ_DIR)/libn/test.o
+	$(LINK)
+
+include share/pop.mk
diff --git a/src/libc/stdio.c b/src/libc/stdio.c
new file mode 100644
index 0000000..8bbbe9a
--- /dev/null
+++ b/src/libc/stdio.c
@@ -0,0 +1,59 @@
+#include <u.h>
+#include <libc.h>
+
+int
+printf(byte* fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+
+    int nw, rem, peek, len;
+    byte *str, c;
+
+    while (*fmt) {
+        rem = INT_MAX - nw;
+
+        if (fmt[0] != '%' || fmt[1] == '%') {
+            if (fmt[0] == '%') fmt++;
+
+            for (peek = 1; fmt[peek] && fmt[peek] != '%'; peek++) {
+                ;
+            }
+            if (rem < peek) return -1;
+            // TODO: Print here.
+            fmt += peek;
+            nw  += peek;
+            continue;
+        }
+
+        str = fmt++;
+
+        switch (*fmt++) {
+        case 'c':
+            c = va_arg(args, int);
+            if (rem < 0) return -1;
+            // TODO: Print here
+            nw++;
+            break;
+
+        case 's':
+            str = va_arg(args, byte*);
+            len = strlen(str);
+            if (rem < len) return -1;
+            // TODO: Print here
+            nw += len;
+            break;
+        default:
+            fmt = str;
+            len = strlen(fmt);
+            if (rem < len) return -1;
+            // TODO: Print here
+            nw += len;
+            fmt += len;
+            break;
+        }
+    }
+
+    va_end(args);
+    return nw;
+}
diff --git a/src/libc/string.c b/src/libc/string.c
new file mode 100644
index 0000000..0e41efa
--- /dev/null
+++ b/src/libc/string.c
@@ -0,0 +1,80 @@
+#include <u.h>
+#include <libc.h>
+
+void*
+memcopy(void *dst, void *src, intptr n)
+{
+    byte *e, *s, *d; 
+
+    d = dst;
+    e = d + n;
+    for (s = src ; d != e; ++s, ++d) {
+        *d = *s;
+    }
+
+    return dst;
+}
+
+void*
+memmove(void *dst, void *src, intptr n)
+{
+    byte *e, *s, *d;
+    s = src;
+    d = dst;
+
+    if (d < s) {
+        e = d + n;
+        for (; d != e; ++s, ++d) 
+            *d = *s;
+
+    } else {
+        e = d;
+        d += n;
+        s += n;
+        for (; d != e; --s, --d)
+            d[-1] = s[-1];
+    }
+
+    return dst;
+}
+
+void*
+memset(void *buf, int val, intptr n)
+{
+    byte *b, *e;
+    b = buf;
+    e = b + n;
+    for (; b != e; b++) {
+        *b = (byte)val;
+    }
+
+    return buf;
+}
+
+int
+memcmp(void *lhs, void *rhs, intptr n)
+{
+    byte *bl, *br, *e;
+
+    br = rhs;
+    e  = br + n;
+    for (bl = lhs; br != e; ++bl, ++br) {
+        if (*bl < *br)
+            return -1;
+        else if (*bl > *br) 
+            return 1;
+    }
+
+    return 0;
+}
+
+int
+strlen(byte* s)
+{
+    byte* b;
+    for (b = s; *b; b++) {
+        ;
+    }
+
+    return b - s;
+}