Autocreate files that prevent MacOS indexing of the CIRCUITPYTHON dive

.. the price of this appears to be about 112 bytes of flash and 12
bytes of RAM, according to the stats printed during the build.

It also uses up 4 directory entries (out of 128), but does not reduce
the number of blocks usable for storing file contents.

These are the same items noted in the Adafruit README for Trinket M0
as preventing MacOS indexing.

Closes: #689

1 files changed, 14 insertions, 0 deletions

diff --git a/ports/atmel-samd/supervisor/filesystem.c b/ports/atmel-samd/supervisor/filesystem.c
index 45dc5667b..90478ad16 100644
--- a/ports/atmel-samd/supervisor/filesystem.c
+++ b/ports/atmel-samd/supervisor/filesystem.c
@@ -42,6 +42,12 @@
 fs_user_mount_t fs_user_mount_flash;
 mp_vfs_mount_t mp_vfs_mount_flash;
 
+static void make_empty_file(FATFS *fatfs, const char *path) {
+    FIL fp;
+    f_open(fatfs, &fp, path, FA_WRITE | FA_CREATE_ALWAYS);
+    f_close(&fp);
+}
+
 // we don't make this function static because it needs a lot of stack and we
 // want it to be executed without using stack within main() function
 void filesystem_init(bool create_allowed) {
@@ -65,6 +71,14 @@ void filesystem_init(bool create_allowed) {
 
         // set label
         f_setlabel(&vfs_fat->fatfs, "CIRCUITPY");
+
+        // inhibit file indexing on MacOS
+        f_mkdir(&vfs_fat->fatfs, "/.fseventsd");
+        make_empty_file(&vfs_fat->fatfs, "/.metadata_never_index");
+        make_empty_file(&vfs_fat->fatfs, "/.Trashes");
+        make_empty_file(&vfs_fat->fatfs, "/.feventsd/no_log");
+
+        // and ensure everything is flushed
         flash_flush();
     } else if (res != FR_OK) {
         return;