writer: framebuf_utils is now Pyboard-only. Matches reality :)

writer/WRITER.md

@@ -271,19 +271,21 @@ the `framebuf.blit` method the class renders glyphs one pixel at a time. There
 is a way to improve performance. It was developed by Jim Mussared (@jimmo) and
 consists of a native C module.
 
+This works well on Pyboards (1.x and D) but I have had no success on other
+platforms including the Raspberry Pi Pico. The code will silently ignore this
+module on other platforms. The following applies only when run on a Pyboard.
+
 On import, `writer.py` attempts to import a module `framebuf_utils`. If this
 succeeds, glyph rendering will be substantially faster. If the file is not
-present the class will work using normal rendering. If the file exists but was
-compiled for a different architecture a warning message will be printed. This
-is a harmless advisory - the code will run using normal rendering.
+present the class will work using normal rendering. If the file is missing or
+invalid a harmless advisory note is printed and the code will run using normal
+rendering.
 
 The directory `framebuf_utils` contains the source file, the makefile and a
 version of `framebuf_utils.mpy` for `armv7m` architecture (e.g. Pyboards).
-ESP32 users with access to the development toolchain should change `Makefile`
-to specify the `xtensawin` arch and rebuild.
-
-It is suggested that moving the appropriate `framebuf_utils.mpy` to the target
-is only done once the basic operation of an application has been verified.
+This allows for recompiling for other architectures if anyone feels like
+experimenting. However the fact that it crashes the Pico suggests that the code
+is highly specific to the Pybaord.
 
 The module has a `fast_mode` variable which is set `True` on import if the mode
 was successfully engaged. User code should treat this as read-only.

writer/writer.py

@@ -25,9 +25,9 @@ import framebuf
 from uctypes import bytearray_at, addressof
 from sys import platform
 
-__version__ = (0, 4, 1)
+__version__ = (0, 4, 2)
 
-fast_mode = platform != 'rp2'  # framebuf_utils crashes RP2
+fast_mode = platform == 'pyboard'
 if fast_mode:
     try:
         try:
@@ -39,8 +39,8 @@ if fast_mode:
                 fast_mode = False
     except ValueError:
         fast_mode = False
-if not fast_mode:
-    print('Ignoring framebuf_utils.mpy: compiled for incorrect architecture.')
+    if not fast_mode:
+        print('Ignoring missing or invalid framebuf_utils.mpy.')
 
 
 class DisplayState():