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

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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.
This commit is contained in:
Thomas Quiniou 2025-10-06 08:42:03 +02:00
parent ccabdec2f8
commit 3453311f08
1 changed files with 61 additions and 35 deletions
Download patch file Download diff file Expand all files Collapse all files

96
portable/IAR/RL78/port.c
View file

@ -93,12 +93,10 @@ 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
@ -106,9 +104,13 @@ StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
* 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. */
@ -116,65 +118,89 @@ StackType_t * pxPortInitialiseStack( StackType_t * 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 )