add agnostic files

adafruit_platformdetect/board.py

@@ -1024,6 +1024,7 @@ class Board:
             yield self.board.QTPY_U2IF
             yield self.board.QT2040_TRINKEY_U2IF
             yield self.board.KB2040_U2IF
+            yield self.board.OS_AGNOSTIC_BOARD
 
         return any(condition for condition in lazily_generate_conditions())
 
@@ -1093,6 +1094,11 @@ class Board:
         """Check whether the current board is a Microchip MCP2221."""
         return self.id == boards.MICROCHIP_MCP2221
 
+    @property
+    def os_agnostic_board(self) -> bool:
+        """Check whether the current board is an OS agnostic special case."""
+        return self.id == boards.OS_AGNOSTIC_BOARD
+
     @property
     def pico_u2if(self) -> bool:
         """Check whether the current board is a RPi Pico w/ u2if."""

adafruit_platformdetect/chip.py

@@ -98,6 +98,10 @@ class Chip:
                     "BLINKA_MCP2221 environment variable "
                     + "set, but no MCP2221 device found"
                 )
+            if os.environ.get("BLINKA_OS_AGNOSTIC"):
+                # we don't need to look for this chip, it's just a flag
+                self._chip_id = chips.OS_AGNOSTIC
+                return self._chip_id
             if os.environ.get("BLINKA_U2IF"):
                 import hid
 

adafruit_platformdetect/constants/boards.py

@@ -588,3 +588,6 @@ _MILKV_IDS_ = (MILKV_DUO,)
 
 # Luckfox
 _LUCKFOX_IDS = (LUCKFOX_PICO_MAX,)
+
+# Agnostic board
+OS_AGNOSTIC_BOARD = "OS_AGNOSTIC_BOARD"

adafruit_platformdetect/constants/chips.py

@@ -4,6 +4,7 @@
 
 """Definition of chips."""
 A311D = "A311D"
+OS_AGNOSTIC = "OS_AGNOSTIC"
 AM33XX = "AM33XX"
 AM625X = "AM625X"
 AM65XX = "AM65XX"