fix[RL78 Port] incorrect register image for pvParameters in FAR model (#1316) (#1317)

In the RL78 FAR data model, pxPortInitialiseStack() did not initialize the register image for the task parameter (pvParameters) correctly. A:DE registers were saved with dummy values instead of the actual pointer. Effect: on first context restore the function prologue read a corrupted parameter. NEAR builds were not affected. This patch aligns the FAR path with the calling convention and compiler version: - IAR V2: pass pvParameters via registers → DE = low 16 bits, A = high 8 - IAR V1 (fallback): keep legacy stack write Also keeps the original stack-frame layout and updates the comment to reflect that pointer sizes depend on __DATA_MODEL__. Result: tasks in FAR receive the correct parameter at entry; NEAR remains unchanged. Co-authored-by: Thomas Quiniou <tquiniou@fdi-access.com>

Author: sauleThsQuin

portable/IAR/RL78/port.c

@@ -93,88 +93,114 @@ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
  void * pvParameters )
 {
  uint32_t * pulLocal;
-
- /* With large code and large data sizeof( StackType_t ) == 2, and
- * sizeof( StackType_t * ) == 4. With small code and small data
- * sizeof( StackType_t ) == 2 and sizeof( StackType_t * ) == 2. */
-
- #if __DATA_MODEL__ == __DATA_MODEL_FAR__
+ /* With large data sizeof( StackType_t ) == 2, and
+ * sizeof( StackType_t * ) == 4. With small data
+ * sizeof( StackType_t ) == 2 and sizeof( StackType_t * ) == 2. */
+#if __DATA_MODEL__ == __DATA_MODEL_FAR__
  {
  /* Far pointer parameters are passed using the A:DE registers (24-bit).
  * Although they are stored in memory as a 32-bit value. Hence decrement
  * the stack pointer, so 2 bytes are left for the contents of A, before
  * storing the pvParameters value. */
  pxTopOfStack--;
  pulLocal = ( uint32_t * ) pxTopOfStack;
- *pulLocal = ( uint32_t ) pvParameters;
- pxTopOfStack--;
-
+ #if __CALLING_CONVENTION__ == __CC_V2__
+ /* V2: parameter via A:DE, do not push pvParameters on stack */
+ #else
+ /* V1 or unknown: keep stack write */
+ *pulLocal = ( uint32_t ) pvParameters;
+ pxTopOfStack--;
+ #endif
  /* The return address is a 32-bit value. So decrement the stack pointer
  * in order to make extra room needed to store the correct value. See the
  * comments above the prvTaskExitError() prototype at the top of this file. */
  pxTopOfStack--;
  pulLocal = ( uint32_t * ) pxTopOfStack;
  *pulLocal = ( uint32_t ) prvTaskExitError;
  pxTopOfStack--;
-
  /* The task function start address combined with the PSW is also stored
  * as a 32-bit value. So leave a space for the second two bytes. */
  pxTopOfStack--;
  pulLocal = ( uint32_t * ) pxTopOfStack;
  *pulLocal = ( ( ( uint32_t ) pxCode ) | ( portPSW << 24UL ) );
  pxTopOfStack--;
-
- /* An initial value for the AX register. */
- *pxTopOfStack = ( StackType_t ) 0x1111;
+ /* Register image on task entry. */
+ #if __CALLING_CONVENTION__ == __CC_V2__
+ {
+ uint32_t p = ( uint32_t ) pvParameters;
+ uint16_t de_init = (uint16_t)( p & 0xFFFFU );
+ uint16_t ax_init = (uint16_t)( ((p >> 16) & 0xFFU) << 8 );
+ /* AX register image */
+ *pxTopOfStack = ( StackType_t ) ax_init;
+ pxTopOfStack--;
+ /* HL register image (dummy) */
+ *pxTopOfStack = ( StackType_t ) 0x2222;
+ pxTopOfStack--;
+ /* CS:ES register image */
+ *pxTopOfStack = ( StackType_t ) 0x0F00;
+ pxTopOfStack--;
+ /* DE register image */
+ *pxTopOfStack = ( StackType_t ) de_init;
+ pxTopOfStack--;
+ }
+ #else
+ /* An initial value for the AX register. */
+ *pxTopOfStack = ( StackType_t ) 0x1111;
+ pxTopOfStack--;
+ /* HL register image (dummy) */
+ *pxTopOfStack = ( StackType_t ) 0x2222;
+ pxTopOfStack--;
+ /* CS:ES register image */
+ *pxTopOfStack = ( StackType_t ) 0x0F00;
+ pxTopOfStack--;
+ /* DE register image (dummy) */
+ *pxTopOfStack = ( StackType_t ) 0xDEDE;
+ pxTopOfStack--;
+ #endif
+ /* BC remains a dummy value (not used for parameter passing). */
+ *pxTopOfStack = ( StackType_t ) 0xBCBC;
  pxTopOfStack--;
  }
- #else /* if __DATA_MODEL__ == __DATA_MODEL_FAR__ */
+#else /* if __DATA_MODEL__ == __DATA_MODEL_FAR__ */
  {
-  /* The return address, leaving space for the first two bytes of the
+ /* The return address, leaving space for the first two bytes of the
  * 32-bit value. See the comments above the prvTaskExitError() prototype
  * at the top of this file. */
  pxTopOfStack--;
  pulLocal = ( uint32_t * ) pxTopOfStack;
  *pulLocal = ( uint32_t ) prvTaskExitError;
  pxTopOfStack--;
-
  /* Task function. Again as it is written as a 32-bit value a space is
  * left on the stack for the second two bytes. */
  pxTopOfStack--;
-
  /* Task function start address combined with the PSW. */
  pulLocal = ( uint32_t * ) pxTopOfStack;
  *pulLocal = ( ( ( uint32_t ) pxCode ) | ( portPSW << 24UL ) );
  pxTopOfStack--;
-
  /* The parameter is passed in AX. */
  *pxTopOfStack = ( StackType_t ) pvParameters;
  pxTopOfStack--;
+ /* An initial value for the HL register. */
+ *pxTopOfStack = ( StackType_t ) 0x2222;
+ pxTopOfStack--;
+ /* CS and ES registers. */
+ *pxTopOfStack = ( StackType_t ) 0x0F00;
+ pxTopOfStack--;
+ /* The remaining general purpose registers DE and BC */
+ *pxTopOfStack = ( StackType_t ) 0xDEDE;
+ pxTopOfStack--;
+ *pxTopOfStack = ( StackType_t ) 0xBCBC;
+ pxTopOfStack--;
  }
- #endif /* if __DATA_MODEL__ == __DATA_MODEL_FAR__ */
-
- /* An initial value for the HL register. */
- *pxTopOfStack = ( StackType_t ) 0x2222;
- pxTopOfStack--;
-
- /* CS and ES registers. */
- *pxTopOfStack = ( StackType_t ) 0x0F00;
- pxTopOfStack--;
-
- /* The remaining general purpose registers DE and BC */
- *pxTopOfStack = ( StackType_t ) 0xDEDE;
- pxTopOfStack--;
- *pxTopOfStack = ( StackType_t ) 0xBCBC;
- pxTopOfStack--;
-
+#endif /* __DATA_MODEL__ */
  /* Finally the critical section nesting count is set to zero when the task
  * first starts. */
  *pxTopOfStack = ( StackType_t ) portNO_CRITICAL_SECTION_NESTING;
-
  /* Return a pointer to the top of the stack that has been generated so
  * it can be stored in the task control block for the task. */
  return pxTopOfStack;
 }
+
 /*-----------------------------------------------------------*/
 
 static void prvTaskExitError( void )