diff --git a/common-static.h b/common-static.h
new file mode 100644
index 0000000..854ea37
--- /dev/null
+++ b/common-static.h
@@ -0,0 +1,126 @@
+#pragma once
+
+#include "common.h"
+
+#include <unistd.h>
+#include <errno.h>
+
+static inline void byte_set (void *dst, const char value, size_t size)
+{
+    if (!dst)
+        return;
+
+    char *restrict d = dst;
+
+    while (size--)
+        *d++ = value;
+}
+
+static inline void byte_cpy (void *dst, const void *src, size_t size)
+{
+    if (!dst || !src)
+        return;
+
+    char *restrict d = dst;
+    const char *restrict s = src;
+
+    while (size--)
+        *d++ = *s++;
+}
+
+static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
+{
+    if (!dst || !src)
+        return 0;
+
+    size_t i;
+
+    for (i=0; i<len && src[i]; i++)
+        dst[i] = src[i];
+
+    dst[i] = 0;
+
+    return i;
+}
+
+static inline int str_cmp (const char *restrict sa, const char *restrict sb)
+{
+    if (!sa || !sb)
+        return 1;
+
+     while (*sa==*sb++)
+         if (!*sa++)
+             return 0;
+
+    return 1;
+}
+
+static inline size_t str_len (const char *restrict str)
+{
+    if (!str)
+        return 0;
+
+    size_t i = 0;
+
+    while (str[i])
+        i++;
+
+    return i;
+}
+
+typedef struct buffer buffer_t;
+
+struct buffer {
+    uint8_t *data;
+    uint8_t *read;
+    uint8_t *write;
+    uint8_t *end;
+};
+
+static inline void buffer_setup (buffer_t *buffer, void *data, size_t size)
+{
+    if (!data)
+        data = malloc(ALIGN(size));
+
+    buffer->data  = data;
+    buffer->read  = data;
+    buffer->write = data;
+    buffer->end   = data;
+    buffer->end  += size;
+}
+
+static inline void buffer_format (buffer_t *buffer)
+{
+    buffer->write = buffer->data;
+    buffer->read  = buffer->data;
+}
+
+static inline size_t buffer_size (buffer_t *buffer)
+{
+    return buffer->end-buffer->data;
+}
+
+static inline size_t buffer_write_size (buffer_t *buffer)
+{
+    return buffer->end-buffer->write;
+}
+
+static inline size_t buffer_read_size (buffer_t *buffer)
+{
+    return buffer->write-buffer->read;
+}
+
+static inline void buffer_shift (buffer_t *buffer)
+{
+    if (buffer->read==buffer->write) {
+        buffer_format(buffer);
+    } else {
+        const uint8_t *src = PALIGN_DOWN(buffer->read);
+        const size_t size = ALIGN(buffer->write-src);
+        if (buffer->data+size<src) {
+            byte_cpy(buffer->data, src, size);
+            buffer->read  -= src-buffer->data;
+            buffer->write -= src-buffer->data;
+        }
+    }
+}