* Xtensa: fix the coproc_area incorrect issue
foss-xtensa/amazon-freertos#2 mentioned a issue:
1.
In function pxPortInitialiseStack(StackType_t *pxTopOfStack....)
p = (uint32_t *)(((uint32_t) pxTopOfStack - XT_CP_SIZE) & ~0xf);
In function prvInitialiseNewTask (file: task.c)
pxTopOfStack = (pxStack + (ulStackDepth - 1)) & (~portBYTE_ALIGNMENT_MASK)
So the co-processor area is at
p = (uint32_t *)(((uint32_t)((pxStack + (ulStackDepth - 1)) & (~portBYTE_ALIGNMENT_MASK)) - XT_CP_SIZE) & ~0xf);
2.
In function vPortStoreTaskMPUSettings( .... , StackType_t pxBottomOfStack ...)
xMPUSettings->coproc_area = (StackType_t)((((uint32_t)(pxBottomOfStack + usStackDepth - 1)) - XT_CP_SIZE) & ~0xf);
pxBottomOfStack = pxStack
=> xMPUSettings->coproc_area = (StackType_t*)((((uint32_t)(pxStack+ ulStackDepth - 1)) - XT_CP_SIZE ) & ~0xf);
The p is coproc_area that should be equal to xMPUSettings->coproc_area.
For example, assume pxStack is 0xa0000000, ulStackDepth is 0x2000,
portBYTE_ALIGNMENT_MASK is 0x7f, XT_CP_SIZE is 0x100.
The p = (uint32_t)(((uint32_t)((pxStack + (ulStackDepth - 1)) & (~portBYTE_ALIGNMENT_MASK)) - XT_CP_SIZE) & ~0xf)
= 0xa0001e80
The xMPUSettings->coproc_area = (StackType_t)((((uint32_t)(pxStack+ usStackDepth - 1)) - XT_CP_SIZE ) & ~0xf)
= 0xa0001ef0
Obviously, the p is not equal to the xMPUSettings->coproc_area, which will cause context switching error.
Signed-off-by: magicse7en <magicse7en@outlook.com>
* Update port.c
Co-authored-by: Carl Lundin <53273776+lundinc2@users.noreply.github.com>
In function pxPortInitialiseStack of port.c:
sp = ( StackType_t * ) ( ( ( UBaseType_t ) ( pxTopOfStack + 1 ) - XT_CP_SIZE - XT_STK_FRMSZ ) & ~0xf );
We assume XT_CP_SIZE is 0xE4, XT_STK_FRMSZ is 0xA0, pxTopOfStack is 0xA0000000, sp is 0x9FFFFE80.
From port.c, we know the frame->a1 as below:
frame->a1 = ( UBaseType_t ) sp + XT_STK_FRMSZ; /* physical top of stack frame */
So frame->a1 is 0x9FFFFF20. Therefore the interrupt stack frame range is 0x9FFFFE80 ~ 0x9FFFFF20.
The coproc_area is: p = ( uint32_t * ) ( ( ( uint32_t ) pxTopOfStack - XT_CP_SIZE ) & ~0xf );
So its value is 0x9FFFFF10. Obviously, the interrupt stack frame overlaps the coproc_area.
Co-authored-by: Carl Lundin <53273776+lundinc2@users.noreply.github.com>
* Style: Change FreeRTOS websites in comments
* Style: Change freertos to FreeRTOS in comments
* Style: Remove broken link
Co-authored-by: Alfred Gedeon <gedeonag@amazon.com>
Paul Bartell
j4cbo
Cobus van Eeden
David Chalco
Carl Lundin
magicse7en
David Chalco
alfred gedeon
Alfred Gedeon
Yuhui Zheng