diff --git a/zephyr/Makefile b/zephyr/Makefile
new file mode 100644
index 0000000000..42897bcaf7
--- /dev/null
+++ b/zephyr/Makefile
@@ -0,0 +1,69 @@
+#
+# This is main Makefile, which uses MicroPython build system, but
+# Zephyr arch-specific toolchain (setup by Zephyr's Makefile.toolchain.*).
+# Unfortunately, it's currently not possible to get target (as in: specific
+# board to run on) specific compile-time options from Zephyr, so these must
+# be set (duplicated) in this Makefile. Currently, these configured for
+# ARM Cortex-M3. This Makefile builds MicroPython as a library, and then
+# calls recursively Makefile.zephyr to build complete application using
+# Zephyr build system.
+#
+
+ARCH ?= x86
+BOARD ?= qemu_x86
+# Zephyr 1.5.0
+#OUTDIR_PREFIX =
+# Zephyr 1.6.0
+OUTDIR_PREFIX = $(BOARD)
+
+# Zephyr toolchain config is 2-pass, so included twice
+include $(ZEPHYR_BASE)/scripts/Makefile.toolchain.$(ZEPHYR_GCC_VARIANT)
+include $(ZEPHYR_BASE)/scripts/Makefile.toolchain.$(ZEPHYR_GCC_VARIANT)
+
+CFLAGS_arm = -mthumb -mcpu=cortex-m3 -mabi=aapcs
+CFLAGS_x86 = -fno-asynchronous-unwind-tables -ffreestanding -fno-stack-protector \
+    -fno-omit-frame-pointer -mpreferred-stack-boundary=2 -mno-sse -march=pentium
+CFLAGS_TARGET = $(CFLAGS_$(ARCH))
+
+include ../py/mkenv.mk
+include ../py/py.mk
+
+INC += -I.
+INC += -I..
+INC += -I$(BUILD)
+INC += -I$(ZEPHYR_BASE)/include -I$(ZEPHYR_BASE) \
+    -Ioutdir/$(OUTDIR_PREFIX)/misc/generated/sysgen \
+    -I$(dir $(Z_AUTOCONF_H))
+
+SRC_C = main.c \
+	uart_core.c \
+	lib/utils/stdout_helpers.c \
+	lib/utils/printf.c \
+	lib/utils/pyexec.c \
+	lib/mp-readline/readline.c \
+	$(SRC_MOD)
+
+OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
+
+COPT = -Os -DNDEBUG -fdata-sections -ffunction-sections
+CFLAGS = -std=gnu99 $(TOOLCHAIN_CFLAGS) $(INC) $(CFLAGS_MOD) $(COPT) $(CFLAGS_TARGET)
+
+include ../py/mkrules.mk
+
+all: $(LIBMICROPYTHON)
+	$(MAKE) -f Makefile.zephyr BOARD=$(BOARD)
+
+qemu: all
+	$(MAKE) -f Makefile.zephyr qemu BOARD=$(BOARD)
+
+Z_AUTOCONF_H = outdir/$(OUTDIR_PREFIX)/include/generated/autoconf.h
+
+$(LIBMICROPYTHON): $(Z_AUTOCONF_H)
+build/genhdr/qstr.i.last: $(Z_AUTOCONF_H)
+
+$(Z_AUTOCONF_H):
+	rm -f $(LIBMICROPYTHON)
+	-$(MAKE) -f Makefile.zephyr BOARD=$(BOARD)
+
+# Clean Zephyr things too
+CLEAN_EXTRA = outdir
diff --git a/zephyr/main.c b/zephyr/main.c
new file mode 100644
index 0000000000..65074b157e
--- /dev/null
+++ b/zephyr/main.c
@@ -0,0 +1,95 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "py/nlr.h"
+#include "py/compile.h"
+#include "py/runtime.h"
+#include "py/repl.h"
+#include "py/gc.h"
+#include "lib/utils/pyexec.h"
+
+void do_str(const char *src, mp_parse_input_kind_t input_kind) {
+    mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, src, strlen(src), 0);
+    if (lex == NULL) {
+        printf("MemoryError: lexer could not allocate memory\n");
+        return;
+    }
+
+    nlr_buf_t nlr;
+    if (nlr_push(&nlr) == 0) {
+        qstr source_name = lex->source_name;
+        mp_parse_tree_t parse_tree = mp_parse(lex, input_kind);
+        mp_obj_t module_fun = mp_compile(&parse_tree, source_name, MP_EMIT_OPT_NONE, true);
+        mp_call_function_0(module_fun);
+        nlr_pop();
+    } else {
+        // uncaught exception
+        mp_obj_print_exception(&mp_plat_print, (mp_obj_t)nlr.ret_val);
+    }
+}
+
+static char *stack_top;
+static char heap[16 * 1024];
+
+int real_main(void) {
+    int stack_dummy;
+    stack_top = (char*)&stack_dummy;
+
+    #if MICROPY_ENABLE_GC
+    gc_init(heap, heap + sizeof(heap));
+    #endif
+    mp_init();
+    #if MICROPY_REPL_EVENT_DRIVEN
+    pyexec_event_repl_init();
+    for (;;) {
+        int c = mp_hal_stdin_rx_chr();
+        if (pyexec_event_repl_process_char(c)) {
+            break;
+        }
+    }
+    #else
+    pyexec_friendly_repl();
+    #endif
+    //do_str("print('hello world!', list(x+1 for x in range(10)), end='eol\\n')", MP_PARSE_SINGLE_INPUT);
+    //do_str("for i in range(10):\r\n  print(i)", MP_PARSE_FILE_INPUT);
+    mp_deinit();
+    return 0;
+}
+
+void gc_collect(void) {
+    // WARNING: This gc_collect implementation doesn't try to get root
+    // pointers from CPU registers, and thus may function incorrectly.
+    void *dummy;
+    gc_collect_start();
+    gc_collect_root(&dummy, ((mp_uint_t)stack_top - (mp_uint_t)&dummy) / sizeof(mp_uint_t));
+    gc_collect_end();
+    gc_dump_info();
+}
+
+mp_lexer_t *mp_lexer_new_from_file(const char *filename) {
+    return NULL;
+}
+
+mp_import_stat_t mp_import_stat(const char *path) {
+    return MP_IMPORT_STAT_NO_EXIST;
+}
+
+mp_obj_t mp_builtin_open(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
+
+void nlr_jump_fail(void *val) {
+}
+
+void NORETURN __fatal_error(const char *msg) {
+    while (1);
+}
+
+#ifndef NDEBUG
+void MP_WEAK __assert_func(const char *file, int line, const char *func, const char *expr) {
+    printf("Assertion '%s' failed, at file %s:%d\n", expr, file, line);
+    __fatal_error("Assertion failed");
+}
+#endif
diff --git a/zephyr/mpconfigport.h b/zephyr/mpconfigport.h
new file mode 100644
index 0000000000..cf5884e0e7
--- /dev/null
+++ b/zephyr/mpconfigport.h
@@ -0,0 +1,49 @@
+#include <alloca.h>
+
+// Saving extra crumbs to make sure binary fits in 128K
+#define MICROPY_COMP_CONST_FOLDING  (0)
+#define MICROPY_COMP_CONST (0)
+#define MICROPY_COMP_DOUBLE_TUPLE_ASSIGN (0)
+
+#define MICROPY_ENABLE_GC           (1)
+#define MICROPY_HELPER_REPL         (1)
+#define MICROPY_REPL_AUTO_INDENT    (1)
+#define MICROPY_CPYTHON_COMPAT      (0)
+#define MICROPY_PY_ASYNC_AWAIT      (0)
+#define MICROPY_PY_ATTRTUPLE        (0)
+#define MICROPY_PY_BUILTINS_ENUMERATE (0)
+#define MICROPY_PY_BUILTINS_FILTER  (0)
+#define MICROPY_PY_BUILTINS_MIN_MAX (0)
+#define MICROPY_PY_BUILTINS_PROPERTY (0)
+#define MICROPY_PY_BUILTINS_RANGE_ATTRS (0)
+#define MICROPY_PY_BUILTINS_REVERSED (0)
+#define MICROPY_PY_BUILTINS_SET     (0)
+#define MICROPY_PY_BUILTINS_SLICE   (0)
+#define MICROPY_PY_ARRAY            (0)
+#define MICROPY_PY_COLLECTIONS      (0)
+#define MICROPY_PY_CMATH            (0)
+#define MICROPY_PY_IO               (0)
+#define MICROPY_PY_STRUCT           (0)
+#define MICROPY_PY_SYS_MODULES      (0)
+#define MICROPY_LONGINT_IMPL (MICROPY_LONGINT_IMPL_LONGLONG)
+#define MICROPY_FLOAT_IMPL (MICROPY_FLOAT_IMPL_FLOAT)
+#define MICROPY_PY_BUILTINS_COMPLEX (0)
+#define MICROPY_HW_BOARD_NAME "zephyr-generic"
+#define MICROPY_HW_MCU_NAME "unknown-cpu"
+
+typedef int mp_int_t; // must be pointer size
+typedef unsigned mp_uint_t; // must be pointer size
+
+typedef void *machine_ptr_t; // must be of pointer size
+typedef const void *machine_const_ptr_t; // must be of pointer size
+typedef long mp_off_t;
+
+#define BYTES_PER_WORD (sizeof(mp_int_t))
+
+#define MP_STATE_PORT MP_STATE_VM
+
+#define MICROPY_PORT_ROOT_POINTERS \
+    const char *readline_hist[8];
+
+// Include Zephyr's autoconf.h, which should be made first by Zephyr makefiles
+#include "autoconf.h"
diff --git a/zephyr/mphalport.h b/zephyr/mphalport.h
new file mode 100644
index 0000000000..60d68bd2d6
--- /dev/null
+++ b/zephyr/mphalport.h
@@ -0,0 +1,2 @@
+static inline mp_uint_t mp_hal_ticks_ms(void) { return 0; }
+static inline void mp_hal_set_interrupt_char(char c) {}
diff --git a/zephyr/uart_core.c b/zephyr/uart_core.c
new file mode 100644
index 0000000000..5f48f973f6
--- /dev/null
+++ b/zephyr/uart_core.c
@@ -0,0 +1,22 @@
+#include <unistd.h>
+#include "py/mpconfig.h"
+#include "src/zephyr_getchar.h"
+
+// Stopgap
+extern void printk(const char*, ...);
+
+/*
+ * Core UART functions to implement for a port
+ */
+
+// Receive single character
+int mp_hal_stdin_rx_chr(void) {
+    return zephyr_getchar();
+}
+
+// Send string of given length
+void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
+    while (len--) {
+        printk("%c", *str++);
+    }
+}