py: Factor persistent code load/save funcs into persistentcode.[ch].

6 files changed, 545 insertions, 482 deletions

diff --git a/py/builtinimport.c b/py/builtinimport.c
index e72eaf4724..e197dc7832 100644
--- a/py/builtinimport.c
+++ b/py/builtinimport.c
@@ -32,6 +32,7 @@
 #include "py/nlr.h"
 #include "py/compile.h"
 #include "py/objmodule.h"
+#include "py/persistentcode.h"
 #include "py/runtime.h"
 #include "py/builtin.h"
 #include "py/frozenmod.h"
diff --git a/py/emitglue.c b/py/emitglue.c
index dc5be6e0e0..abcf50cdd4 100644
--- a/py/emitglue.c
+++ b/py/emitglue.c
@@ -171,468 +171,3 @@ mp_obj_t mp_make_closure_from_raw_code(const mp_raw_code_t *rc, mp_uint_t n_clos
     // wrap function in closure object
     return mp_obj_new_closure(ffun, n_closed_over & 0xff, args + ((n_closed_over >> 7) & 2));
 }
-
-#if MICROPY_PERSISTENT_CODE_LOAD || MICROPY_PERSISTENT_CODE_SAVE
-
-#include "py/smallint.h"
-
-// The feature flags byte encodes the compile-time config options that
-// affect the generate bytecode.
-#define MPY_FEATURE_FLAGS ( \
-    ((MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE) << 0) \
-    | ((MICROPY_PY_BUILTINS_STR_UNICODE) << 1) \
-    )
-// This is a version of the flags that can be configured at runtime.
-#define MPY_FEATURE_FLAGS_DYNAMIC ( \
-    ((MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE_DYNAMIC) << 0) \
-    | ((MICROPY_PY_BUILTINS_STR_UNICODE_DYNAMIC) << 1) \
-    )
-
-#if MICROPY_PERSISTENT_CODE_LOAD || (MICROPY_PERSISTENT_CODE_SAVE && !MICROPY_DYNAMIC_COMPILER)
-// The bytecode will depend on the number of bits in a small-int, and
-// this function computes that (could make it a fixed constant, but it
-// would need to be defined in mpconfigport.h).
-STATIC int mp_small_int_bits(void) {
-    mp_int_t i = MP_SMALL_INT_MAX;
-    int n = 1;
-    while (i != 0) {
-        i >>= 1;
-        ++n;
-    }
-    return n;
-}
-#endif
-
-typedef struct _bytecode_prelude_t {
-    uint n_state;
-    uint n_exc_stack;
-    uint scope_flags;
-    uint n_pos_args;
-    uint n_kwonly_args;
-    uint n_def_pos_args;
-    uint code_info_size;
-} bytecode_prelude_t;
-
-// ip will point to start of opcodes
-// ip2 will point to simple_name, source_file qstrs
-STATIC void extract_prelude(const byte **ip, const byte **ip2, bytecode_prelude_t *prelude) {
-    prelude->n_state = mp_decode_uint(ip);
-    prelude->n_exc_stack = mp_decode_uint(ip);
-    prelude->scope_flags = *(*ip)++;
-    prelude->n_pos_args = *(*ip)++;
-    prelude->n_kwonly_args = *(*ip)++;
-    prelude->n_def_pos_args = *(*ip)++;
-    *ip2 = *ip;
-    prelude->code_info_size = mp_decode_uint(ip2);
-    *ip += prelude->code_info_size;
-    while (*(*ip)++ != 255) {
-    }
-}
-
-#endif // MICROPY_PERSISTENT_CODE_LOAD || MICROPY_PERSISTENT_CODE_SAVE
-
-#if MICROPY_PERSISTENT_CODE_LOAD
-
-#include "py/parsenum.h"
-#include "py/bc0.h"
-
-STATIC int read_byte(mp_reader_t *reader) {
-    return reader->read_byte(reader->data);
-}
-
-STATIC void read_bytes(mp_reader_t *reader, byte *buf, size_t len) {
-    while (len-- > 0) {
-        *buf++ = reader->read_byte(reader->data);
-    }
-}
-
-STATIC mp_uint_t read_uint(mp_reader_t *reader) {
-    mp_uint_t unum = 0;
-    for (;;) {
-        byte b = reader->read_byte(reader->data);
-        unum = (unum << 7) | (b & 0x7f);
-        if ((b & 0x80) == 0) {
-            break;
-        }
-    }
-    return unum;
-}
-
-STATIC qstr load_qstr(mp_reader_t *reader) {
-    mp_uint_t len = read_uint(reader);
-    char *str = m_new(char, len);
-    read_bytes(reader, (byte*)str, len);
-    qstr qst = qstr_from_strn(str, len);
-    m_del(char, str, len);
-    return qst;
-}
-
-STATIC mp_obj_t load_obj(mp_reader_t *reader) {
-    byte obj_type = read_byte(reader);
-    if (obj_type == 'e') {
-        return MP_OBJ_FROM_PTR(&mp_const_ellipsis_obj);
-    } else {
-        size_t len = read_uint(reader);
-        vstr_t vstr;
-        vstr_init_len(&vstr, len);
-        read_bytes(reader, (byte*)vstr.buf, len);
-        if (obj_type == 's' || obj_type == 'b') {
-            return mp_obj_new_str_from_vstr(obj_type == 's' ? &mp_type_str : &mp_type_bytes, &vstr);
-        } else if (obj_type == 'i') {
-            return mp_parse_num_integer(vstr.buf, vstr.len, 10, NULL);
-        } else {
-            assert(obj_type == 'f' || obj_type == 'c');
-            return mp_parse_num_decimal(vstr.buf, vstr.len, obj_type == 'c', false, NULL);
-        }
-    }
-}
-
-STATIC void load_bytecode_qstrs(mp_reader_t *reader, byte *ip, byte *ip_top) {
-    while (ip < ip_top) {
-        size_t sz;
-        uint f = mp_opcode_format(ip, &sz);
-        if (f == MP_OPCODE_QSTR) {
-            qstr qst = load_qstr(reader);
-            ip[1] = qst;
-            ip[2] = qst >> 8;
-        }
-        ip += sz;
-    }
-}
-
-STATIC mp_raw_code_t *load_raw_code(mp_reader_t *reader) {
-    // load bytecode
-    mp_uint_t bc_len = read_uint(reader);
-    byte *bytecode = m_new(byte, bc_len);
-    read_bytes(reader, bytecode, bc_len);
-
-    // extract prelude
-    const byte *ip = bytecode;
-    const byte *ip2;
-    bytecode_prelude_t prelude;
-    extract_prelude(&ip, &ip2, &prelude);
-
-    // load qstrs and link global qstr ids into bytecode
-    qstr simple_name = load_qstr(reader);
-    qstr source_file = load_qstr(reader);
-    ((byte*)ip2)[0] = simple_name; ((byte*)ip2)[1] = simple_name >> 8;
-    ((byte*)ip2)[2] = source_file; ((byte*)ip2)[3] = source_file >> 8;
-    load_bytecode_qstrs(reader, (byte*)ip, bytecode + bc_len);
-
-    // load constant table
-    mp_uint_t n_obj = read_uint(reader);
-    mp_uint_t n_raw_code = read_uint(reader);
-    mp_uint_t *const_table = m_new(mp_uint_t, prelude.n_pos_args + prelude.n_kwonly_args + n_obj + n_raw_code);
-    mp_uint_t *ct = const_table;
-    for (mp_uint_t i = 0; i < prelude.n_pos_args + prelude.n_kwonly_args; ++i) {
-        *ct++ = (mp_uint_t)MP_OBJ_NEW_QSTR(load_qstr(reader));
-    }
-    for (mp_uint_t i = 0; i < n_obj; ++i) {
-        *ct++ = (mp_uint_t)load_obj(reader);
-    }
-    for (mp_uint_t i = 0; i < n_raw_code; ++i) {
-        *ct++ = (mp_uint_t)(uintptr_t)load_raw_code(reader);
-    }
-
-    // create raw_code and return it
-    mp_raw_code_t *rc = mp_emit_glue_new_raw_code();
-    mp_emit_glue_assign_bytecode(rc, bytecode, bc_len, const_table,
-        #if MICROPY_PERSISTENT_CODE_SAVE
-        n_obj, n_raw_code,
-        #endif
-        prelude.scope_flags);
-    return rc;
-}
-
-mp_raw_code_t *mp_raw_code_load(mp_reader_t *reader) {
-    byte header[4];
-    read_bytes(reader, header, sizeof(header));
-    if (strncmp((char*)header, "M\x00", 2) != 0) {
-        mp_raise_ValueError("invalid .mpy file");
-    }
-    if (header[2] != MPY_FEATURE_FLAGS || header[3] > mp_small_int_bits()) {
-        mp_raise_ValueError("incompatible .mpy file");
-    }
-    return load_raw_code(reader);
-}
-
-typedef struct _mp_mem_reader_t {
-    const byte *cur;
-    const byte *end;
-} mp_mem_reader_t;
-
-STATIC mp_uint_t mp_mem_reader_next_byte(void *br_in) {
-    mp_mem_reader_t *br = br_in;
-    if (br->cur < br->end) {
-        return *br->cur++;
-    } else {
-        return (mp_uint_t)-1;
-    }
-}
-
-mp_raw_code_t *mp_raw_code_load_mem(const byte *buf, size_t len) {
-    mp_mem_reader_t mr = {buf, buf + len};
-    mp_reader_t reader = {&mr, mp_mem_reader_next_byte};
-    return mp_raw_code_load(&reader);
-}
-
-// here we define mp_raw_code_load_file depending on the port
-// TODO abstract this away properly
-
-#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || defined(__unix__)
-// unix file reader
-
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-
-typedef struct _mp_lexer_file_buf_t {
-    int fd;
-    byte buf[20];
-    mp_uint_t len;
-    mp_uint_t pos;
-} mp_lexer_file_buf_t;
-
-STATIC mp_uint_t file_buf_next_byte(void *fb_in) {
-    mp_lexer_file_buf_t *fb = fb_in;
-    if (fb->pos >= fb->len) {
-        if (fb->len == 0) {
-            return (mp_uint_t)-1;
-        } else {
-            int n = read(fb->fd, fb->buf, sizeof(fb->buf));
-            if (n <= 0) {
-                fb->len = 0;
-                return (mp_uint_t)-1;
-            }
-            fb->len = n;
-            fb->pos = 0;
-        }
-    }
-    return fb->buf[fb->pos++];
-}
-
-mp_raw_code_t *mp_raw_code_load_file(const char *filename) {
-    mp_lexer_file_buf_t fb;
-    fb.fd = open(filename, O_RDONLY, 0644);
-    int n = read(fb.fd, fb.buf, sizeof(fb.buf));
-    fb.len = n;
-    fb.pos = 0;
-    mp_reader_t reader;
-    reader.data = &fb;
-    reader.read_byte = file_buf_next_byte;
-    mp_raw_code_t *rc = mp_raw_code_load(&reader);
-    close(fb.fd);
-    return rc;
-}
-
-#elif defined(__thumb2__) || defined(__xtensa__)
-// fatfs file reader (assume thumb2 arch uses fatfs...)
-
-#include "lib/fatfs/ff.h"
-
-typedef struct _mp_lexer_file_buf_t {
-    FIL fp;
-    byte buf[20];
-    uint16_t len;
-    uint16_t pos;
-} mp_lexer_file_buf_t;
-
-STATIC mp_uint_t file_buf_next_byte(void *fb_in) {
-    mp_lexer_file_buf_t *fb = fb_in;
-    if (fb->pos >= fb->len) {
-        if (fb->len < sizeof(fb->buf)) {
-            return (mp_uint_t)-1;
-        } else {
-            UINT n;
-            f_read(&fb->fp, fb->buf, sizeof(fb->buf), &n);
-            if (n == 0) {
-                return (mp_uint_t)-1;
-            }
-            fb->len = n;
-            fb->pos = 0;
-        }
-    }
-    return fb->buf[fb->pos++];
-}
-
-mp_raw_code_t *mp_raw_code_load_file(const char *filename) {
-    mp_lexer_file_buf_t fb;
-    /*FRESULT res =*/ f_open(&fb.fp, filename, FA_READ);
-    UINT n;
-    f_read(&fb.fp, fb.buf, sizeof(fb.buf), &n);
-    fb.len = n;
-    fb.pos = 0;
-
-    mp_reader_t reader;
-    reader.data = &fb;
-    reader.read_byte = file_buf_next_byte;
-    mp_raw_code_t *rc = mp_raw_code_load(&reader);
-
-    f_close(&fb.fp);
-
-    return rc;
-}
-
-#endif
-
-#endif // MICROPY_PERSISTENT_CODE_LOAD
-
-#if MICROPY_PERSISTENT_CODE_SAVE
-
-#include "py/objstr.h"
-
-STATIC void mp_print_bytes(mp_print_t *print, const byte *data, size_t len) {
-    print->print_strn(print->data, (const char*)data, len);
-}
-
-#define BYTES_FOR_INT ((BYTES_PER_WORD * 8 + 6) / 7)
-STATIC void mp_print_uint(mp_print_t *print, mp_uint_t n) {
-    byte buf[BYTES_FOR_INT];
-    byte *p = buf + sizeof(buf);
-    *--p = n & 0x7f;
-    n >>= 7;
-    for (; n != 0; n >>= 7) {
-        *--p = 0x80 | (n & 0x7f);
-    }
-    print->print_strn(print->data, (char*)p, buf + sizeof(buf) - p);
-}
-
-STATIC void save_qstr(mp_print_t *print, qstr qst) {
-    size_t len;
-    const byte *str = qstr_data(qst, &len);
-    mp_print_uint(print, len);
-    mp_print_bytes(print, str, len);
-}
-
-STATIC void save_obj(mp_print_t *print, mp_obj_t o) {
-    if (MP_OBJ_IS_STR_OR_BYTES(o)) {
-        byte obj_type;
-        if (MP_OBJ_IS_STR(o)) {
-            obj_type = 's';
-        } else {
-            obj_type = 'b';
-        }
-        mp_uint_t len;
-        const char *str = mp_obj_str_get_data(o, &len);
-        mp_print_bytes(print, &obj_type, 1);
-        mp_print_uint(print, len);
-        mp_print_bytes(print, (const byte*)str, len);
-    } else if (MP_OBJ_TO_PTR(o) == &mp_const_ellipsis_obj) {
-        byte obj_type = 'e';
-        mp_print_bytes(print, &obj_type, 1);
-    } else {
-        // we save numbers using a simplistic text representation
-        // TODO could be improved
-        byte obj_type;
-        if (MP_OBJ_IS_TYPE(o, &mp_type_int)) {
-            obj_type = 'i';
-        } else if (mp_obj_is_float(o)) {
-            obj_type = 'f';
-        } else {
-            assert(MP_OBJ_IS_TYPE(o, &mp_type_complex));
-            obj_type = 'c';
-        }
-        vstr_t vstr;
-        mp_print_t pr;
-        vstr_init_print(&vstr, 10, &pr);
-        mp_obj_print_helper(&pr, o, PRINT_REPR);
-        mp_print_bytes(print, &obj_type, 1);
-        mp_print_uint(print, vstr.len);
-        mp_print_bytes(print, (const byte*)vstr.buf, vstr.len);
-        vstr_clear(&vstr);
-    }
-}
-
-STATIC void save_bytecode_qstrs(mp_print_t *print, const byte *ip, const byte *ip_top) {
-    while (ip < ip_top) {
-        size_t sz;
-        uint f = mp_opcode_format(ip, &sz);
-        if (f == MP_OPCODE_QSTR) {
-            qstr qst = ip[1] | (ip[2] << 8);
-            save_qstr(print, qst);
-        }
-        ip += sz;
-    }
-}
-
-STATIC void save_raw_code(mp_print_t *print, mp_raw_code_t *rc) {
-    if (rc->kind != MP_CODE_BYTECODE) {
-        mp_raise_ValueError("can only save bytecode");
-    }
-
-    // save bytecode
-    mp_print_uint(print, rc->data.u_byte.bc_len);
-    mp_print_bytes(print, rc->data.u_byte.bytecode, rc->data.u_byte.bc_len);
-
-    // extract prelude
-    const byte *ip = rc->data.u_byte.bytecode;
-    const byte *ip2;
-    bytecode_prelude_t prelude;
-    extract_prelude(&ip, &ip2, &prelude);
-
-    // save qstrs
-    save_qstr(print, ip2[0] | (ip2[1] << 8)); // simple_name
-    save_qstr(print, ip2[2] | (ip2[3] << 8)); // source_file
-    save_bytecode_qstrs(print, ip, rc->data.u_byte.bytecode + rc->data.u_byte.bc_len);
-
-    // save constant table
-    mp_print_uint(print, rc->data.u_byte.n_obj);
-    mp_print_uint(print, rc->data.u_byte.n_raw_code);
-    const mp_uint_t *const_table = rc->data.u_byte.const_table;
-    for (uint i = 0; i < prelude.n_pos_args + prelude.n_kwonly_args; ++i) {
-        mp_obj_t o = (mp_obj_t)*const_table++;
-        save_qstr(print, MP_OBJ_QSTR_VALUE(o));
-    }
-    for (uint i = 0; i < rc->data.u_byte.n_obj; ++i) {
-        save_obj(print, (mp_obj_t)*const_table++);
-    }
-    for (uint i = 0; i < rc->data.u_byte.n_raw_code; ++i) {
-        save_raw_code(print, (mp_raw_code_t*)(uintptr_t)*const_table++);
-    }
-}
-
-void mp_raw_code_save(mp_raw_code_t *rc, mp_print_t *print) {
-    // header contains:
-    //  byte  'M'
-    //  byte  version
-    //  byte  feature flags
-    //  byte  number of bits in a small int
-    byte header[4] = {'M', 0, MPY_FEATURE_FLAGS_DYNAMIC,
-        #if MICROPY_DYNAMIC_COMPILER
-        mp_dynamic_compiler.small_int_bits,
-        #else
-        mp_small_int_bits(),
-        #endif
-    };
-    mp_print_bytes(print, header, sizeof(header));
-
-    save_raw_code(print, rc);
-}
-
-// here we define mp_raw_code_save_file depending on the port
-// TODO abstract this away properly
-
-#if defined(__i386__) || defined(__x86_64__) || (defined(__arm__) && (defined(__unix__)))
-
-#include <unistd.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-
-STATIC void fd_print_strn(void *env, const char *str, size_t len) {
-    int fd = (intptr_t)env;
-    ssize_t ret = write(fd, str, len);
-    (void)ret;
-}
-
-void mp_raw_code_save_file(mp_raw_code_t *rc, const char *filename) {
-    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-    mp_print_t fd_print = {(void*)(intptr_t)fd, fd_print_strn};
-    mp_raw_code_save(rc, &fd_print);
-    close(fd);
-}
-
-#else
-#error mp_raw_code_save_file not implemented for this platform
-#endif
-
-#endif // MICROPY_PERSISTENT_CODE_SAVE
diff --git a/py/emitglue.h b/py/emitglue.h
index f5618577d5..37c4f1b18f 100644
--- a/py/emitglue.h
+++ b/py/emitglue.h
@@ -74,21 +74,4 @@ void mp_emit_glue_assign_native(mp_raw_code_t *rc, mp_raw_code_kind_t kind, void
 mp_obj_t mp_make_function_from_raw_code(const mp_raw_code_t *rc, mp_obj_t def_args, mp_obj_t def_kw_args);
 mp_obj_t mp_make_closure_from_raw_code(const mp_raw_code_t *rc, mp_uint_t n_closed_over, const mp_obj_t *args);
 
-#if MICROPY_PERSISTENT_CODE_LOAD
-typedef struct _mp_reader_t {
-    void *data;
-    mp_uint_t (*read_byte)(void *data);
-    void (*close)(void *data);
-} mp_reader_t;
-
-mp_raw_code_t *mp_raw_code_load(mp_reader_t *reader);
-mp_raw_code_t *mp_raw_code_load_mem(const byte *buf, size_t len);
-mp_raw_code_t *mp_raw_code_load_file(const char *filename);
-#endif
-
-#if MICROPY_PERSISTENT_CODE_SAVE
-void mp_raw_code_save(mp_raw_code_t *rc, mp_print_t *print);
-void mp_raw_code_save_file(mp_raw_code_t *rc, const char *filename);
-#endif
-
 #endif // __MICROPY_INCLUDED_PY_EMITGLUE_H__
diff --git a/py/persistentcode.c b/py/persistentcode.c
new file mode 100644
index 0000000000..31f147a095
--- /dev/null
+++ b/py/persistentcode.c
@@ -0,0 +1,499 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2016 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include "py/emitglue.h"
+#include "py/persistentcode.h"
+#include "py/bc.h"
+
+#if MICROPY_PERSISTENT_CODE_LOAD || MICROPY_PERSISTENT_CODE_SAVE
+
+#include "py/smallint.h"
+
+// The feature flags byte encodes the compile-time config options that
+// affect the generate bytecode.
+#define MPY_FEATURE_FLAGS ( \
+    ((MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE) << 0) \
+    | ((MICROPY_PY_BUILTINS_STR_UNICODE) << 1) \
+    )
+// This is a version of the flags that can be configured at runtime.
+#define MPY_FEATURE_FLAGS_DYNAMIC ( \
+    ((MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE_DYNAMIC) << 0) \
+    | ((MICROPY_PY_BUILTINS_STR_UNICODE_DYNAMIC) << 1) \
+    )
+
+#if MICROPY_PERSISTENT_CODE_LOAD || (MICROPY_PERSISTENT_CODE_SAVE && !MICROPY_DYNAMIC_COMPILER)
+// The bytecode will depend on the number of bits in a small-int, and
+// this function computes that (could make it a fixed constant, but it
+// would need to be defined in mpconfigport.h).
+STATIC int mp_small_int_bits(void) {
+    mp_int_t i = MP_SMALL_INT_MAX;
+    int n = 1;
+    while (i != 0) {
+        i >>= 1;
+        ++n;
+    }
+    return n;
+}
+#endif
+
+typedef struct _bytecode_prelude_t {
+    uint n_state;
+    uint n_exc_stack;
+    uint scope_flags;
+    uint n_pos_args;
+    uint n_kwonly_args;
+    uint n_def_pos_args;
+    uint code_info_size;
+} bytecode_prelude_t;
+
+// ip will point to start of opcodes
+// ip2 will point to simple_name, source_file qstrs
+STATIC void extract_prelude(const byte **ip, const byte **ip2, bytecode_prelude_t *prelude) {
+    prelude->n_state = mp_decode_uint(ip);
+    prelude->n_exc_stack = mp_decode_uint(ip);
+    prelude->scope_flags = *(*ip)++;
+    prelude->n_pos_args = *(*ip)++;
+    prelude->n_kwonly_args = *(*ip)++;
+    prelude->n_def_pos_args = *(*ip)++;
+    *ip2 = *ip;
+    prelude->code_info_size = mp_decode_uint(ip2);
+    *ip += prelude->code_info_size;
+    while (*(*ip)++ != 255) {
+    }
+}
+
+#endif // MICROPY_PERSISTENT_CODE_LOAD || MICROPY_PERSISTENT_CODE_SAVE
+
+#if MICROPY_PERSISTENT_CODE_LOAD
+
+#include "py/parsenum.h"
+#include "py/bc0.h"
+
+STATIC int read_byte(mp_reader_t *reader) {
+    return reader->read_byte(reader->data);
+}
+
+STATIC void read_bytes(mp_reader_t *reader, byte *buf, size_t len) {
+    while (len-- > 0) {
+        *buf++ = reader->read_byte(reader->data);
+    }
+}
+
+STATIC mp_uint_t read_uint(mp_reader_t *reader) {
+    mp_uint_t unum = 0;
+    for (;;) {
+        byte b = reader->read_byte(reader->data);
+        unum = (unum << 7) | (b & 0x7f);
+        if ((b & 0x80) == 0) {
+            break;
+        }
+    }
+    return unum;
+}
+
+STATIC qstr load_qstr(mp_reader_t *reader) {
+    mp_uint_t len = read_uint(reader);
+    char *str = m_new(char, len);
+    read_bytes(reader, (byte*)str, len);
+    qstr qst = qstr_from_strn(str, len);
+    m_del(char, str, len);
+    return qst;
+}
+
+STATIC mp_obj_t load_obj(mp_reader_t *reader) {
+    byte obj_type = read_byte(reader);
+    if (obj_type == 'e') {
+        return MP_OBJ_FROM_PTR(&mp_const_ellipsis_obj);
+    } else {
+        size_t len = read_uint(reader);
+        vstr_t vstr;
+        vstr_init_len(&vstr, len);
+        read_bytes(reader, (byte*)vstr.buf, len);
+        if (obj_type == 's' || obj_type == 'b') {
+            return mp_obj_new_str_from_vstr(obj_type == 's' ? &mp_type_str : &mp_type_bytes, &vstr);
+        } else if (obj_type == 'i') {
+            return mp_parse_num_integer(vstr.buf, vstr.len, 10, NULL);
+        } else {
+            assert(obj_type == 'f' || obj_type == 'c');
+            return mp_parse_num_decimal(vstr.buf, vstr.len, obj_type == 'c', false, NULL);
+        }
+    }
+}
+
+STATIC void load_bytecode_qstrs(mp_reader_t *reader, byte *ip, byte *ip_top) {
+    while (ip < ip_top) {
+        size_t sz;
+        uint f = mp_opcode_format(ip, &sz);
+        if (f == MP_OPCODE_QSTR) {
+            qstr qst = load_qstr(reader);
+            ip[1] = qst;
+            ip[2] = qst >> 8;
+        }
+        ip += sz;
+    }
+}
+
+STATIC mp_raw_code_t *load_raw_code(mp_reader_t *reader) {
+    // load bytecode
+    mp_uint_t bc_len = read_uint(reader);
+    byte *bytecode = m_new(byte, bc_len);
+    read_bytes(reader, bytecode, bc_len);
+
+    // extract prelude
+    const byte *ip = bytecode;
+    const byte *ip2;
+    bytecode_prelude_t prelude;
+    extract_prelude(&ip, &ip2, &prelude);
+
+    // load qstrs and link global qstr ids into bytecode
+    qstr simple_name = load_qstr(reader);
+    qstr source_file = load_qstr(reader);
+    ((byte*)ip2)[0] = simple_name; ((byte*)ip2)[1] = simple_name >> 8;
+    ((byte*)ip2)[2] = source_file; ((byte*)ip2)[3] = source_file >> 8;
+    load_bytecode_qstrs(reader, (byte*)ip, bytecode + bc_len);
+
+    // load constant table
+    mp_uint_t n_obj = read_uint(reader);
+    mp_uint_t n_raw_code = read_uint(reader);
+    mp_uint_t *const_table = m_new(mp_uint_t, prelude.n_pos_args + prelude.n_kwonly_args + n_obj + n_raw_code);
+    mp_uint_t *ct = const_table;
+    for (mp_uint_t i = 0; i < prelude.n_pos_args + prelude.n_kwonly_args; ++i) {
+        *ct++ = (mp_uint_t)MP_OBJ_NEW_QSTR(load_qstr(reader));
+    }
+    for (mp_uint_t i = 0; i < n_obj; ++i) {
+        *ct++ = (mp_uint_t)load_obj(reader);
+    }
+    for (mp_uint_t i = 0; i < n_raw_code; ++i) {
+        *ct++ = (mp_uint_t)(uintptr_t)load_raw_code(reader);
+    }
+
+    // create raw_code and return it
+    mp_raw_code_t *rc = mp_emit_glue_new_raw_code();
+    mp_emit_glue_assign_bytecode(rc, bytecode, bc_len, const_table,
+        #if MICROPY_PERSISTENT_CODE_SAVE
+        n_obj, n_raw_code,
+        #endif
+        prelude.scope_flags);
+    return rc;
+}
+
+mp_raw_code_t *mp_raw_code_load(mp_reader_t *reader) {
+    byte header[4];
+    read_bytes(reader, header, sizeof(header));
+    if (strncmp((char*)header, "M\x00", 2) != 0) {
+        mp_raise_ValueError("invalid .mpy file");
+    }
+    if (header[2] != MPY_FEATURE_FLAGS || header[3] > mp_small_int_bits()) {
+        mp_raise_ValueError("incompatible .mpy file");
+    }
+    return load_raw_code(reader);
+}
+
+typedef struct _mp_mem_reader_t {
+    const byte *cur;
+    const byte *end;
+} mp_mem_reader_t;
+
+STATIC mp_uint_t mp_mem_reader_next_byte(void *br_in) {
+    mp_mem_reader_t *br = br_in;
+    if (br->cur < br->end) {
+        return *br->cur++;
+    } else {
+        return (mp_uint_t)-1;
+    }
+}
+
+mp_raw_code_t *mp_raw_code_load_mem(const byte *buf, size_t len) {
+    mp_mem_reader_t mr = {buf, buf + len};
+    mp_reader_t reader = {&mr, mp_mem_reader_next_byte};
+    return mp_raw_code_load(&reader);
+}
+
+// here we define mp_raw_code_load_file depending on the port
+// TODO abstract this away properly
+
+#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || defined(__unix__)
+// unix file reader
+
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+typedef struct _mp_lexer_file_buf_t {
+    int fd;
+    byte buf[20];
+    mp_uint_t len;
+    mp_uint_t pos;
+} mp_lexer_file_buf_t;
+
+STATIC mp_uint_t file_buf_next_byte(void *fb_in) {
+    mp_lexer_file_buf_t *fb = fb_in;
+    if (fb->pos >= fb->len) {
+        if (fb->len == 0) {
+            return (mp_uint_t)-1;
+        } else {
+            int n = read(fb->fd, fb->buf, sizeof(fb->buf));
+            if (n <= 0) {
+                fb->len = 0;
+                return (mp_uint_t)-1;
+            }
+            fb->len = n;
+            fb->pos = 0;
+        }
+    }
+    return fb->buf[fb->pos++];
+}
+
+mp_raw_code_t *mp_raw_code_load_file(const char *filename) {
+    mp_lexer_file_buf_t fb;
+    fb.fd = open(filename, O_RDONLY, 0644);
+    int n = read(fb.fd, fb.buf, sizeof(fb.buf));
+    fb.len = n;
+    fb.pos = 0;
+    mp_reader_t reader;
+    reader.data = &fb;
+    reader.read_byte = file_buf_next_byte;
+    mp_raw_code_t *rc = mp_raw_code_load(&reader);
+    close(fb.fd);
+    return rc;
+}
+
+#elif defined(__thumb2__) || defined(__xtensa__)
+// fatfs file reader (assume thumb2 arch uses fatfs...)
+
+#include "lib/fatfs/ff.h"
+
+typedef struct _mp_lexer_file_buf_t {
+    FIL fp;
+    byte buf[20];
+    uint16_t len;
+    uint16_t pos;
+} mp_lexer_file_buf_t;
+
+STATIC mp_uint_t file_buf_next_byte(void *fb_in) {
+    mp_lexer_file_buf_t *fb = fb_in;
+    if (fb->pos >= fb->len) {
+        if (fb->len < sizeof(fb->buf)) {
+            return (mp_uint_t)-1;
+        } else {
+            UINT n;
+            f_read(&fb->fp, fb->buf, sizeof(fb->buf), &n);
+            if (n == 0) {
+                return (mp_uint_t)-1;
+            }
+            fb->len = n;
+            fb->pos = 0;
+        }
+    }
+    return fb->buf[fb->pos++];
+}
+
+mp_raw_code_t *mp_raw_code_load_file(const char *filename) {
+    mp_lexer_file_buf_t fb;
+    /*FRESULT res =*/ f_open(&fb.fp, filename, FA_READ);
+    UINT n;
+    f_read(&fb.fp, fb.buf, sizeof(fb.buf), &n);
+    fb.len = n;
+    fb.pos = 0;
+
+    mp_reader_t reader;
+    reader.data = &fb;
+    reader.read_byte = file_buf_next_byte;
+    mp_raw_code_t *rc = mp_raw_code_load(&reader);
+
+    f_close(&fb.fp);
+
+    return rc;
+}
+
+#endif
+
+#endif // MICROPY_PERSISTENT_CODE_LOAD
+
+#if MICROPY_PERSISTENT_CODE_SAVE
+
+#include "py/objstr.h"
+
+STATIC void mp_print_bytes(mp_print_t *print, const byte *data, size_t len) {
+    print->print_strn(print->data, (const char*)data, len);
+}
+
+#define BYTES_FOR_INT ((BYTES_PER_WORD * 8 + 6) / 7)
+STATIC void mp_print_uint(mp_print_t *print, mp_uint_t n) {
+    byte buf[BYTES_FOR_INT];
+    byte *p = buf + sizeof(buf);
+    *--p = n & 0x7f;
+    n >>= 7;
+    for (; n != 0; n >>= 7) {
+        *--p = 0x80 | (n & 0x7f);
+    }
+    print->print_strn(print->data, (char*)p, buf + sizeof(buf) - p);
+}
+
+STATIC void save_qstr(mp_print_t *print, qstr qst) {
+    size_t len;
+    const byte *str = qstr_data(qst, &len);
+    mp_print_uint(print, len);
+    mp_print_bytes(print, str, len);
+}
+
+STATIC void save_obj(mp_print_t *print, mp_obj_t o) {
+    if (MP_OBJ_IS_STR_OR_BYTES(o)) {
+        byte obj_type;
+        if (MP_OBJ_IS_STR(o)) {
+            obj_type = 's';
+        } else {
+            obj_type = 'b';
+        }
+        mp_uint_t len;
+        const char *str = mp_obj_str_get_data(o, &len);
+        mp_print_bytes(print, &obj_type, 1);
+        mp_print_uint(print, len);
+        mp_print_bytes(print, (const byte*)str, len);
+    } else if (MP_OBJ_TO_PTR(o) == &mp_const_ellipsis_obj) {
+        byte obj_type = 'e';
+        mp_print_bytes(print, &obj_type, 1);
+    } else {
+        // we save numbers using a simplistic text representation
+        // TODO could be improved
+        byte obj_type;
+        if (MP_OBJ_IS_TYPE(o, &mp_type_int)) {
+            obj_type = 'i';
+        } else if (mp_obj_is_float(o)) {
+            obj_type = 'f';
+        } else {
+            assert(MP_OBJ_IS_TYPE(o, &mp_type_complex));
+            obj_type = 'c';
+        }
+        vstr_t vstr;
+        mp_print_t pr;
+        vstr_init_print(&vstr, 10, &pr);
+        mp_obj_print_helper(&pr, o, PRINT_REPR);
+        mp_print_bytes(print, &obj_type, 1);
+        mp_print_uint(print, vstr.len);
+        mp_print_bytes(print, (const byte*)vstr.buf, vstr.len);
+        vstr_clear(&vstr);
+    }
+}
+
+STATIC void save_bytecode_qstrs(mp_print_t *print, const byte *ip, const byte *ip_top) {
+    while (ip < ip_top) {
+        size_t sz;
+        uint f = mp_opcode_format(ip, &sz);
+        if (f == MP_OPCODE_QSTR) {
+            qstr qst = ip[1] | (ip[2] << 8);
+            save_qstr(print, qst);
+        }
+        ip += sz;
+    }
+}
+
+STATIC void save_raw_code(mp_print_t *print, mp_raw_code_t *rc) {
+    if (rc->kind != MP_CODE_BYTECODE) {
+        mp_raise_ValueError("can only save bytecode");
+    }
+
+    // save bytecode
+    mp_print_uint(print, rc->data.u_byte.bc_len);
+    mp_print_bytes(print, rc->data.u_byte.bytecode, rc->data.u_byte.bc_len);
+
+    // extract prelude
+    const byte *ip = rc->data.u_byte.bytecode;
+    const byte *ip2;
+    bytecode_prelude_t prelude;
+    extract_prelude(&ip, &ip2, &prelude);
+
+    // save qstrs
+    save_qstr(print, ip2[0] | (ip2[1] << 8)); // simple_name
+    save_qstr(print, ip2[2] | (ip2[3] << 8)); // source_file
+    save_bytecode_qstrs(print, ip, rc->data.u_byte.bytecode + rc->data.u_byte.bc_len);
+
+    // save constant table
+    mp_print_uint(print, rc->data.u_byte.n_obj);
+    mp_print_uint(print, rc->data.u_byte.n_raw_code);
+    const mp_uint_t *const_table = rc->data.u_byte.const_table;
+    for (uint i = 0; i < prelude.n_pos_args + prelude.n_kwonly_args; ++i) {
+        mp_obj_t o = (mp_obj_t)*const_table++;
+        save_qstr(print, MP_OBJ_QSTR_VALUE(o));
+    }
+    for (uint i = 0; i < rc->data.u_byte.n_obj; ++i) {
+        save_obj(print, (mp_obj_t)*const_table++);
+    }
+    for (uint i = 0; i < rc->data.u_byte.n_raw_code; ++i) {
+        save_raw_code(print, (mp_raw_code_t*)(uintptr_t)*const_table++);
+    }
+}
+
+void mp_raw_code_save(mp_raw_code_t *rc, mp_print_t *print) {
+    // header contains:
+    //  byte  'M'
+    //  byte  version
+    //  byte  feature flags
+    //  byte  number of bits in a small int
+    byte header[4] = {'M', 0, MPY_FEATURE_FLAGS_DYNAMIC,
+        #if MICROPY_DYNAMIC_COMPILER
+        mp_dynamic_compiler.small_int_bits,
+        #else
+        mp_small_int_bits(),
+        #endif
+    };
+    mp_print_bytes(print, header, sizeof(header));
+
+    save_raw_code(print, rc);
+}
+
+// here we define mp_raw_code_save_file depending on the port
+// TODO abstract this away properly
+
+#if defined(__i386__) || defined(__x86_64__) || (defined(__arm__) && (defined(__unix__)))
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+STATIC void fd_print_strn(void *env, const char *str, size_t len) {
+    int fd = (intptr_t)env;
+    ssize_t ret = write(fd, str, len);
+    (void)ret;
+}
+
+void mp_raw_code_save_file(mp_raw_code_t *rc, const char *filename) {
+    int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    mp_print_t fd_print = {(void*)(intptr_t)fd, fd_print_strn};
+    mp_raw_code_save(rc, &fd_print);
+    close(fd);
+}
+
+#else
+#error mp_raw_code_save_file not implemented for this platform
+#endif
+
+#endif // MICROPY_PERSISTENT_CODE_SAVE
diff --git a/py/persistentcode.h b/py/persistentcode.h
new file mode 100644
index 0000000000..8859bc577a
--- /dev/null
+++ b/py/persistentcode.h
@@ -0,0 +1,44 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2016 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MICROPY_INCLUDED_PY_PERSISTENTCODE_H
+#define MICROPY_INCLUDED_PY_PERSISTENTCODE_H
+
+#include "py/obj.h"
+
+typedef struct _mp_reader_t {
+    void *data;
+    mp_uint_t (*read_byte)(void *data);
+    void (*close)(void *data);
+} mp_reader_t;
+
+mp_raw_code_t *mp_raw_code_load(mp_reader_t *reader);
+mp_raw_code_t *mp_raw_code_load_mem(const byte *buf, size_t len);
+mp_raw_code_t *mp_raw_code_load_file(const char *filename);
+
+void mp_raw_code_save(mp_raw_code_t *rc, mp_print_t *print);
+void mp_raw_code_save_file(mp_raw_code_t *rc, const char *filename);
+
+#endif // MICROPY_INCLUDED_PY_PERSISTENTCODE_H
diff --git a/py/py.mk b/py/py.mk
index 88c4fafe94..b0962d178f 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -134,6 +134,7 @@ PY_O_BASENAME = \
 	parsenumbase.o \
 	parsenum.o \
 	emitglue.o \
+	persistentcode.o \
 	runtime.o \
 	runtime_utils.o \
 	nativeglue.o \