diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/reference/mpyfiles.rst | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/docs/reference/mpyfiles.rst b/docs/reference/mpyfiles.rst index cd4db623f..b2d552d09 100644 --- a/docs/reference/mpyfiles.rst +++ b/docs/reference/mpyfiles.rst @@ -80,6 +80,10 @@ If importing an .mpy file fails then try the following: above, or by inspecting the ``MPY_CROSS_FLAGS`` Makefile variable for the port that you are using. +* If the third byte of the .mpy file has bit #6 set, then check whether the + encoded architecture-specific flag bits vuint is compatible with the + target you're importing the file on. + The following table shows the correspondence between MicroPython release and .mpy version. @@ -153,10 +157,31 @@ size field ====== ================================ byte value 0x4d (ASCII 'M') byte .mpy major version number -byte native arch and minor version number (was feature flags in older versions) +byte feature flags, native arch, minor version number (was feature flags in older versions) byte number of bits in a small int ====== ================================ +The third byte is split as follows (MSB first): + +====== ================================ +bit meaning +====== ================================ +7 reserved, must be 0 +6 an architecture-specific flags vuint follows the header +5..2 native arch number +1..0 minor version number +====== ================================ + +Architecture-specific flags +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +If bit #6 of the header's feature flags byte is set, then a vuint containing +optional architecture-specific information will follow the header. The contents +of this integer depends on which native architecture the file is meant for. + +See also ``mpy-tool.py``'s ``-march-flags`` command-line option to set this +value when creating MPY files. + The global qstr and constant tables ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |