TLS: Add configRESET_TLS_BLOCK macro to reset TLS to default value

Useful when calling libc functions in exception handlers.

Author: paulbartell

include/FreeRTOS.h

@@ -117,19 +117,23 @@
 #if ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 )
 
     #ifndef configTLS_BLOCK_TYPE
-        #error Missing definition:  configTLS_BLOCK_TYPE must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+        #error Missing definition:  configTLS_BLOCK_TYPE must be defined when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
     #endif
 
     #ifndef configINIT_TLS_BLOCK
-        #error Missing definition:  configINIT_TLS_BLOCK must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+        #error Missing definition:  configINIT_TLS_BLOCK must be defined when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
     #endif
 
     #ifndef configSET_TLS_BLOCK
-        #error Missing definition:  configSET_TLS_BLOCK must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+        #error Missing definition:  configSET_TLS_BLOCK must be defined when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+    #endif
+
+    #ifndef configRESET_TLS_BLOCK
+        #error Missing definition:  configRESET_TLS_BLOCK must be defined when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
     #endif
 
     #ifndef configDEINIT_TLS_BLOCK
-        #error Missing definition:  configDEINIT_TLS_BLOCK must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+        #error Missing definition:  configDEINIT_TLS_BLOCK must be defined when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
     #endif
 #endif /* if ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) */
 

include/newlib-freertos.h

@@ -65,6 +65,15 @@
     while( 0 )
 #endif /* configSET_TLS_BLOCK */
 
+#ifndef configRESET_TLS_BLOCK
+    #define configRESET_TLS_BLOCK()       \
+    do                                    \
+    {                                     \
+        _impure_ptr = _global_impure_ptr; \
+    }                                     \
+    while( 0 )
+#endif /* configRESET_TLS_BLOCK */
+
 #ifndef configDEINIT_TLS_BLOCK
     #define configDEINIT_TLS_BLOCK( xTLSBlock ) \
     do                                          \

include/picolibc-freertos.h

@@ -92,6 +92,10 @@
     #define configSET_TLS_BLOCK( xTLSBlock )    _set_tls( xTLSBlock )
 #endif /* configSET_TLS_BLOCK */
 
+#ifndef configRESET_TLS_BLOCK
+    #define configRESET_TLS_BLOCK( xTLSBlock )
+#endif /* configRESET_TLS_BLOCK */
+
 #ifndef configDEINIT_TLS_BLOCK
     #define configDEINIT_TLS_BLOCK( xTLSBlock )
 #endif /* configDEINIT_TLS_BLOCK */