palette2: Add support for P2 devices (#4057)

Module which bring support for P2 devices running in connected mode. This enables using a Palette2 directly with Klippy without Octoprint, or without Palette2 plugins for Octoprint which are not functional out of the box with Klipper.

Signed-off-by: Clifford Roche <clifford.roche@gmail.com>

klippy/extras/virtual_sdcard.py

@@ -91,6 +91,12 @@ class VirtualSD:
             self.must_pause_work = True
             while self.work_timer is not None and not self.cmd_from_sd:
                 self.reactor.pause(self.reactor.monotonic() + .001)
+    def do_resume(self):
+        if self.work_timer is not None:
+            raise self.gcode.error("SD busy")
+        self.must_pause_work = False
+        self.work_timer = self.reactor.register_timer(
+            self.work_handler, self.reactor.NOW)
     # G-Code commands
     def cmd_error(self, gcmd):
         raise gcmd.error("SD write not supported")
@@ -167,11 +173,7 @@ class VirtualSD:
         self.print_stats.set_current_file(filename)
     def cmd_M24(self, gcmd):
         # Start/resume SD print
-        if self.work_timer is not None:
-            raise gcmd.error("SD busy")
-        self.must_pause_work = False
-        self.work_timer = self.reactor.register_timer(
-            self.work_handler, self.reactor.NOW)
+        self.do_resume()
     def cmd_M25(self, gcmd):
         # Pause SD print
         self.do_pause()