♻️ Refactor HAL as singleton (#23357, #23871, #23897)

Marlin/src/inc/MarlinConfig.h

@@ -29,6 +29,7 @@
 
 #ifndef __MARLIN_DEPS__
   #include "../HAL/HAL.h"
+  extern MarlinHAL hal;
 #endif
 
 #include "../pins/pins.h"

Marlin/src/inc/SanityCheck.h

@@ -3891,3 +3891,10 @@ static_assert(_PLUS_TEST(4), "HOMING_FEEDRATE_MM_M values must be positive.");
 #undef _TEST_PWM
 #undef _LINEAR_AXES_STR
 #undef _LOGICAL_AXES_STR
+
+// JTAG support in the HAL
+#if ENABLED(DISABLE_DEBUG) && !defined(JTAGSWD_DISABLE)
+  #error "DISABLE_DEBUG is not supported for the selected MCU/Board."
+#elif ENABLED(DISABLE_JTAG) && !defined(JTAG_DISABLE)
+  #error "DISABLE_JTAG is not supported for the selected MCU/Board."
+#endif