Hi, I'm working on a project with MSP432P401R launchpad. And I have already ported uCOS-III v3.05 to it successfully.
But when I add some functions which deal with float point data, the uCOS-III runs into App_Fault_ISR().
As far as I know, FPU of MSP432 is enabled in default when compiled under CCS Studio v6.1.3.
While uCOS-III does not support FPU feature defaultly, so I have modified *OSTaskStkInit
CPU_STK *OSTaskStkInit (OS_TASK_PTR p_task,
void *p_arg,
CPU_STK *p_stk_base,
CPU_STK *p_stk_limit,
CPU_STK_SIZE stk_size,
OS_OPT opt)
{
CPU_STK *p_stk;
(void)opt; /* Prevent compiler warning */
p_stk = &p_stk_base[stk_size]; /* Load stack pointer */
/* Align the stack to 8-bytes. */
p_stk = (CPU_STK *)((CPU_STK)(p_stk) & 0xFFFFFFF8);
/* Registers stacked as if auto-saved on exception */
#if(OS_CPU_ARM_FP_EN == DEF_ENABLED)
*--p_stk = (CPU_STK)0x00000000u; /* No Name Register */
*--p_stk = (CPU_STK)0x00000000u; /* FPSCR */
*--p_stk = (CPU_STK)0x15151515u; /* S15 */
*--p_stk = (CPU_STK)0x14141414u; /* S14 */
*--p_stk = (CPU_STK)0x13131313u; /* S13 */
*--p_stk = (CPU_STK)0x12121212u; /* S12 */
*--p_stk = (CPU_STK)0x11111111u; /* S11 */
*--p_stk = (CPU_STK)0x10101010u; /* S10 */
*--p_stk = (CPU_STK)0x09090909u; /* S9 */
*--p_stk = (CPU_STK)0x08080808u; /* S8 */
*--p_stk = (CPU_STK)0x07070707u; /* S7 */
*--p_stk = (CPU_STK)0x06060606u; /* S6 */
*--p_stk = (CPU_STK)0x05050505u; /* S5 */
*--p_stk = (CPU_STK)0x04040404u; /* S4 */
*--p_stk = (CPU_STK)0x03030303u; /* S3 */
*--p_stk = (CPU_STK)0x02020202u; /* S2 */
*--p_stk = (CPU_STK)0x01010101u; /* S1 */
*--p_stk = (CPU_STK)0x00000000u; /* S0 */
#endif
*--p_stk = (CPU_STK)0x01000000u; /* xPSR */
*--p_stk = (CPU_STK)p_task; /* Entry Point */
*--p_stk = (CPU_STK)OS_TaskReturn; /* R14 (LR) */
*--p_stk = (CPU_STK)0x12121212u; /* R12 */
*--p_stk = (CPU_STK)0x03030303u; /* R3 */
*--p_stk = (CPU_STK)0x02020202u; /* R2 */
*--p_stk = (CPU_STK)p_stk_limit; /* R1 */
*--p_stk = (CPU_STK)p_arg; /* R0 : argument */
/* Remaining registers saved on process stack */
#if (OS_CPU_ARM_FP_EN == DEF_ENABLED)
*--p_stk = (CPU_STK)0x31313131u; /* S31 */
*--p_stk = (CPU_STK)0x30303030u; /* S30 */
*--p_stk = (CPU_STK)0x29292929u; /* S29 */
*--p_stk = (CPU_STK)0x28282828u; /* S28 */
*--p_stk = (CPU_STK)0x27272727u; /* S27 */
*--p_stk = (CPU_STK)0x26262626u; /* S26 */
*--p_stk = (CPU_STK)0x25252525u; /* S25 */
*--p_stk = (CPU_STK)0x24242424u; /* S24 */
*--p_stk = (CPU_STK)0x23232323u; /* S23 */
*--p_stk = (CPU_STK)0x22222222u; /* S22 */
*--p_stk = (CPU_STK)0x21212121u; /* S21 */
*--p_stk = (CPU_STK)0x20202020u; /* S20 */
*--p_stk = (CPU_STK)0x19191919u; /* S19 */
*--p_stk = (CPU_STK)0x18181818u; /* S18 */
*--p_stk = (CPU_STK)0x17171717u; /* S17 */
*--p_stk = (CPU_STK)0x16161616u; /* S16 */
#endif
*--p_stk = (CPU_STK)0x11111111u; /* R11 */
*--p_stk = (CPU_STK)0x10101010u; /* R10 */
*--p_stk = (CPU_STK)0x09090909u; /* R9 */
*--p_stk = (CPU_STK)0x08080808u; /* R8 */
*--p_stk = (CPU_STK)0x07070707u; /* R7 */
*--p_stk = (CPU_STK)0x06060606u; /* R6 */
*--p_stk = (CPU_STK)0x05050505u; /* R5 */
*--p_stk = (CPU_STK)0x04040404u; /* R4 */
return (p_stk);
}
and the OS_CPU_PendSVHandler() function
.asmfunc
OS_CPU_PendSVHandler:
CPSID I ; Prevent interruption during context switch
MRS R0, PSP ; PSP is process stack pointer
;.if __TI_TMS470_V7M4__ & __TI_VFP_SUPPORT__
VSTMDB R0!, {S16-S31} ; Save remaining regs s31-s16 on stack
;.endif
STMFD R0!, {R4-R11} ; Save remaining regs r4-11 on process stack
LDR R5, OSTCBCurPtrAddr ; OSTCBCurPtr->OSTCBStkPtr = SP;
LDR R6, [R5]
STR R0, [R6] ; R0 is SP of process being switched out
; At this point, entire context of process has been saved
MOV R4, LR ; Save LR exc_return value
BL OSTaskSwHook ; OSTaskSwHook();
LDR R0, OSPrioCurAddr ; OSPrioCur = OSPrioHighRdy;
LDR R1, OSPrioHighRdyAddr
LDRB R2, [R1]
STRB R2, [R0]
LDR R1, OSTCBHighRdyPtrAddr ; OSTCBCurPtr = OSTCBHighRdyPtr;
LDR R2, [R1]
STR R2, [R5]
ORR LR, R4, #0xF4 ; Ensure exception return uses process stack
LDR R0, [R2] ; R0 is new process SP; SP = OSTCBHighRdyPtr->StkPtr;
LDMFD R0!, {R4-R11} ; Restore r4-11 from new process stack
.if __TI_TMS470_V7M4__ & __TI_VFP_SUPPORT__
VLDMIA R0!, {S16-S31}
.endif
MSR PSP, R0 ; Load PSP with new process SP
CPSIE I
BX LR ; Exception return will restore remaining context
.endasmfunc
.end
In addition, I add "__VFP_FP__" predefine in project config.
Also the "OS_OPT_TASK_SAVE_FP" option is enabled when task in uCOS-III is created.
Despire all the changes, the uCOS-III still runs into App_Fault_ISR() routine after the first task is switch out.
Any one has any idea about the issue? Thank you vech much!
