critical code protection (wip)

Author: d-a-v

Diff for: cores/esp8266/Arduino.h

@@ -165,6 +165,16 @@ void ets_intr_unlock();
 #define interrupts() xt_rsil(0)
 #define noInterrupts() xt_rsil(15)
 
+#define lockEnterVar(varSave, level) __asm__ __volatile__("rsil %0," __STRINGIFY(level) : "=a" (varSave))
+#define lockLeaveVar(varSave)        __asm__ __volatile__("wsr %0,ps; isync" :: "a" (varSave) : "memory")
+
+#define lockDeclM()  uint32_t intrState
+#define lockEnterM() lockEnterVar(intrState, 0)
+#define lockLeaveM() lockLeaveVar(intrState)
+
+#define lockEnter() lockDeclM(); lockEnterM()
+#define lockLeave() lockLeaveM()
+
 #define clockCyclesPerMicrosecond() ( F_CPU / 1000000L )
 #define clockCyclesToMicroseconds(a) ( (a) / clockCyclesPerMicrosecond() )
 #define microsecondsToClockCycles(a) ( (a) * clockCyclesPerMicrosecond() )

Diff for: cores/esp8266/Schedule.cpp

@@ -17,6 +17,7 @@ static scheduled_fn_t* sFirstUnused = 0;
 
 static int sCount = 0;
 
+IRAM_ATTR
 static scheduled_fn_t* get_fn() {
     scheduled_fn_t* result = NULL;
     // try to get an item from unused items list
@@ -39,24 +40,28 @@ static void recycle_fn(scheduled_fn_t* fn)
     sFirstUnused = fn;
 }
 
+IRAM_ATTR
 bool schedule_function_us(mFuncT fn, uint32_t repeat_us)
 {
+    lockEnter();
+
     scheduled_fn_t* item = get_fn();
     if (!item) {
+        lockLeave();
         return false;
     }
     item->mFunc = fn;
-
-    uint32_t savedPS = xt_rsil(0); // noInterrupts();
     item->mNext = sFirst;
     sFirst = item;
-    xt_wsr_ps(savedPS); // interrupts();
 
     if (repeat_us)
         item->callNow.reset(repeat_us);
+
+    lockLeave();
     return true;
 }
 
+IRAM_ATTR
 bool schedule_function(std::function<void(void)> fn)
 {
     return schedule_function_us([&fn](){ fn(); return false; }, 0);
@@ -70,10 +75,10 @@ void run_scheduled_functions()
         toCall = item->mNext;
         if (item->callNow && !item->mFunc())
         {
-            uint32_t savedPS = xt_rsil(0); // noInterrupts();
+            lockEnter();
             if (sFirst == item)
                 sFirst = item->mNext;
-            xt_wsr_ps(savedPS); // interrupts();
+            lockLeave();
 
             item->mFunc = mFuncT();
             recycle_fn(item);

Diff for: tests/host/common/c_types.h

@@ -102,6 +102,9 @@ typedef enum {
 #define ICACHE_RODATA_ATTR
 #endif /* ICACHE_FLASH */
 
+// counterpart https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp8266-compat.h
+#define IRAM_ATTR ICACHE_RAM_ATTR
+
 #define STORE_ATTR __attribute__((aligned(4)))
 
 #ifndef __cplusplus

Diff for: tools/sdk/include/c_types.h

@@ -93,6 +93,9 @@ typedef enum {
 #define ICACHE_RAM_ATTR
 #endif /* ICACHE_FLASH */
 
+// counterpart https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp8266-compat.h
+#define IRAM_ATTR ICACHE_RAM_ATTR
+
 #define STORE_ATTR __attribute__((aligned(4)))
 
 #ifndef __cplusplus