Merge pull request #4713 from jepler/mpy-magic-number

Change the first byte of CircuitPython 'mpy' files to "C"

Author: jepler

mpy-cross/main.c

@@ -210,8 +210,8 @@ MP_NOINLINE int main_(int argc, char **argv) {
             if (strcmp(argv[a], "-X") == 0) {
                 a += 1;
             } else if (strcmp(argv[a], "--version") == 0) {
-                printf("MicroPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE
-                    "; mpy-cross emitting mpy v" MP_STRINGIFY(MPY_VERSION) "\n");
+                printf("CircuitPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE
+                    "; mpy-cross emitting mpy v" MP_STRINGIFY(MPY_VERSION) "-CircuitPython\n");
                 return 0;
             } else if (strcmp(argv[a], "-v") == 0) {
                 mp_verbose_flag++;

py/persistentcode.c

@@ -564,7 +564,7 @@ STATIC mp_raw_code_t *load_raw_code(mp_reader_t *reader, qstr_window_t *qw) {
 mp_raw_code_t *mp_raw_code_load(mp_reader_t *reader) {
     byte header[4];
     read_bytes(reader, header, sizeof(header));
-    if (header[0] != 'M'
+    if (header[0] != 'C'
         || header[1] != MPY_VERSION
         || MPY_FEATURE_DECODE_FLAGS(header[2]) != MPY_FEATURE_FLAGS
         || header[3] > mp_small_int_bits()
@@ -819,7 +819,7 @@ void mp_raw_code_save(mp_raw_code_t *rc, mp_print_t *print) {
     //  byte  number of bits in a small int
     //  uint  size of qstr window
     byte header[4] = {
-        'M',
+        'C',
         MPY_VERSION,
         MPY_FEATURE_ENCODE_FLAGS(MPY_FEATURE_FLAGS_DYNAMIC),
         #if MICROPY_DYNAMIC_COMPILER

tests/import/mpy_native.py

@@ -58,10 +58,10 @@ def open(self, path, mode):
 # these are the test .mpy files
 user_files = {
     # bad architecture
-    "/mod0.mpy": b"M\x05\xff\x00\x10",
+    "/mod0.mpy": b"C\x05\xff\x00\x10",
     # test loading of viper and asm
     "/mod1.mpy": (
-        b"M\x05\x0b\x1f\x20"  # header
+        b"C\x05\x0b\x1f\x20"  # header
         b"\x20"  # n bytes, bytecode
         b"\x00\x08\x02m\x02m"  # prelude
         b"\x51"  # LOAD_CONST_NONE
@@ -78,7 +78,7 @@ def open(self, path, mode):
     ),
     # test loading viper with truncated data
     "/mod2.mpy": (
-        b"M\x05\x0b\x1f\x20"  # header
+        b"C\x05\x0b\x1f\x20"  # header
         b"\x20"  # n bytes, bytecode
         b"\x00\x08\x02m\x02m"  # prelude
         b"\x51"  # LOAD_CONST_NONE
@@ -88,7 +88,7 @@ def open(self, path, mode):
     ),
     # test loading viper with additional scope flags and relocation
     "/mod3.mpy": (
-        b"M\x05\x0b\x1f\x20"  # header
+        b"C\x05\x0b\x1f\x20"  # header
         b"\x20"  # n bytes, bytecode
         b"\x00\x08\x02m\x02m"  # prelude
         b"\x51"  # LOAD_CONST_NONE

tools/mpy-tool.py

@@ -767,8 +767,8 @@ def read_raw_code(f, qstr_win):
 def read_mpy(filename):
     with open(filename, "rb") as f:
         header = bytes_cons(f.read(4))
-        if header[0] != ord("M"):
-            raise Exception("not a valid .mpy file")
+        if header[0] != ord("C"):
+            raise Exception("not a valid CircuitPython .mpy file")
         if header[1] != config.MPY_VERSION:
             raise Exception("incompatible .mpy version")
         feature_byte = header[2]

tools/mpy_ld.py

@@ -909,7 +909,7 @@ def build_mpy(env, entry_offset, fmpy, native_qstr_vals, native_qstr_objs):
     out.write_bytes(
         bytearray(
             [
-                ord("M"),
+                ord("C"),
                 MPY_VERSION,
                 env.arch.mpy_feature,
                 MP_SMALL_INT_BITS,