/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * * * (c) Copyright 2009-2013; Micrium, Inc.; Weston, FL * All rights reserved. Protected by international copyright laws. * * ARM Cortex-M4 Port * * File : OS_CPU_C.C * Version : V2.92.09 * By : JJL * BAN * * LICENSING TERMS: * --------------- * uC/OS-II is provided in source form for FREE short-term evaluation, for educational use or * for peaceful research. If you plan or intend to use uC/OS-II in a commercial application/ * product then, you need to contact Micrium to properly license uC/OS-II for its use in your * experience uC/OS-II. The fact that the source is provided does NOT mean that you can use * it commercially without paying a licensing fee. * * Knowledge of the source code may NOT be used to develop a similar product. * * Please help us continue to provide the embedded community with the finest software available. * Your honesty is greatly appreciated. * * You can contact us at www.micrium.com, or by phone at +1 (954) 217-2036. * * For : ARMv7 Cortex-M4 * Mode : Thumb-2 ISA * Toolchain : IAR EWARM ********************************************************************************************************* */ #define OS_CPU_GLOBALS /* ********************************************************************************************************* * INCLUDE FILES ********************************************************************************************************* */ #include //#include /********************************************************************************************************* * LOCAL VARIABLES ********************************************************************************************************* */ #if OS_TMR_EN > 0u static INT16U OSTmrCtr; #endif /* ********************************************************************************************************* * SYS TICK DEFINES ********************************************************************************************************* */ //#define OS_CPU_CM4_NVIC_ST_CTRL (*((volatile INT32U *)0xE000E010uL)) /* SysTick Ctrl & Status Reg. */ //#define OS_CPU_CM4_NVIC_ST_RELOAD (*((volatile INT32U *)0xE000E014uL)) /* SysTick Reload Value Reg. */ //#define OS_CPU_CM4_NVIC_ST_CURRENT (*((volatile INT32U *)0xE000E018uL)) /* SysTick Current Value Reg. */ //#define OS_CPU_CM4_NVIC_ST_CAL (*((volatile INT32U *)0xE000E01CuL)) /* SysTick Cal Value Reg. */ //#define OS_CPU_CM4_NVIC_SHPRI1 (*((volatile INT32U *)0xE000ED18uL)) /* System Handlers 4 to 7 Prio. */ //#define OS_CPU_CM4_NVIC_SHPRI2 (*((volatile INT32U *)0xE000ED1CuL)) /* System Handlers 8 to 11 Prio. */ //#define OS_CPU_CM4_NVIC_SHPRI3 (*((volatile INT32U *)0xE000ED20uL)) /* System Handlers 12 to 15 Prio. */ #define OS_CPU_CM4_NVIC_ST_CTRL_COUNT 0x00010000uL /* Count flag. */ #define OS_CPU_CM4_NVIC_ST_CTRL_CLK_SRC 0x00000004uL /* Clock Source. */ #define OS_CPU_CM4_NVIC_ST_CTRL_INTEN 0x00000002uL /* Interrupt enable. */ #define OS_CPU_CM4_NVIC_ST_CTRL_ENABLE 0x00000001uL /* Counter mode. */ #define OS_CPU_CM4_NVIC_PRIO_MIN 0xFFu /* Min handler prio. */ /* ********************************************************************************************************* * OS INITIALIZATION HOOK * (BEGINNING) * * Description: This function is called by OSInit() at the beginning of OSInit(). * * Arguments : none * * Note(s) : 1) Interrupts should be disabled during this call. ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSInitHookBegin (void) { INT32U size; OS_STK *pstk; /* Clear exception stack for stack checking. */ pstk = &OS_CPU_ExceptStk[0]; size = OS_CPU_EXCEPT_STK_SIZE; while (size > 0u) { size--; *pstk++ = (OS_STK)0; } /* Align the ISR stack to 8-bytes */ OS_CPU_ExceptStkBase = (OS_STK *)&OS_CPU_ExceptStk[OS_CPU_EXCEPT_STK_SIZE]; OS_CPU_ExceptStkBase = (OS_STK *)((OS_STK)(OS_CPU_ExceptStkBase) & 0xFFFFFFF8); #if OS_TMR_EN > 0u OSTmrCtr = 0u; #endif } #endif /* ********************************************************************************************************* * OS INITIALIZATION HOOK * (END) * * Description: This function is called by OSInit() at the end of OSInit(). * * Arguments : none * * Note(s) : 1) Interrupts should be disabled during this call. ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSInitHookEnd (void) { } #endif /* ********************************************************************************************************* * TASK CREATION HOOK * * Description: This function is called when a task is created. * * Arguments : ptcb is a pointer to the task control block of the task being created. * * Note(s) : 1) Interrupts are disabled during this call. ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSTaskCreateHook (OS_TCB *ptcb) { #if OS_APP_HOOKS_EN > 0u App_TaskCreateHook(ptcb); #else (void)ptcb; /* Prevent compiler warning */ #endif } #endif /* ********************************************************************************************************* * TASK DELETION HOOK * * Description: This function is called when a task is deleted. * * Arguments : ptcb is a pointer to the task control block of the task being deleted. * * Note(s) : 1) Interrupts are disabled during this call. ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSTaskDelHook (OS_TCB *ptcb) { #if OS_APP_HOOKS_EN > 0u App_TaskDelHook(ptcb); #else (void)ptcb; /* Prevent compiler warning */ #endif } #endif /* ********************************************************************************************************* * IDLE TASK HOOK * * Description: This function is called by the idle task. This hook has been added to allow you to do * such things as STOP the CPU to conserve power. * * Arguments : none * * Note(s) : 1) Interrupts are enabled during this call. ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSTaskIdleHook (void) { #if OS_APP_HOOKS_EN > 0u App_TaskIdleHook(); #endif } #endif /* ********************************************************************************************************* * TASK RETURN HOOK * * Description: This function is called if a task accidentally returns. In other words, a task should * either be an infinite loop or delete itself when done. * * Arguments : ptcb is a pointer to the task control block of the task that is returning. * * Note(s) : none ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSTaskReturnHook (OS_TCB *ptcb) { #if OS_APP_HOOKS_EN > 0u App_TaskReturnHook(ptcb); #else (void)ptcb; #endif } #endif /* ********************************************************************************************************* * STATISTIC TASK HOOK * * Description: This function is called every second by uC/OS-II's statistics task. This allows your * application to add functionality to the statistics task. * * Arguments : none ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSTaskStatHook (void) { #if OS_APP_HOOKS_EN > 0u App_TaskStatHook(); #endif } #endif /* ********************************************************************************************************* * INITIALIZE A TASK'S STACK * * Description: This function is called by either OSTaskCreate() or OSTaskCreateExt() to initialize the * stack frame of the task being created. This function is highly processor specific. * * Arguments : task is a pointer to the task code * * p_arg is a pointer to a user supplied data area that will be passed to the task * when the task first executes. * * ptos is a pointer to the top of stack. It is assumed that 'ptos' points to * a 'free' entry on the task stack. If OS_STK_GROWTH is set to 1 then * 'ptos' will contain the HIGHEST valid address of the stack. Similarly, if * OS_STK_GROWTH is set to 0, the 'ptos' will contains the LOWEST valid address * of the stack. * * opt specifies options that can be used to alter the behavior of OSTaskStkInit(). * (see uCOS_II.H for OS_TASK_OPT_xxx). * * Returns : Always returns the location of the new top-of-stack once the processor registers have * been placed on the stack in the proper order. * * Note(s) : (1) Interrupts are enabled when task starts executing. * * (2) All tasks run in Thread mode, using process stack. * * (3) There are two different stack frames depending on whether the Floating-Point(FP) * co-processor is enabled or not. * * (a) The stack frame shown in the diagram is used when the FP co-processor is not present and * OS_TASK_OPT_SAVE_FP is disabled. In this case, the FP registers and FP Status Control * register are not saved in the stack frame. * * (b) If the FP co-processor is present but the OS_TASK_OPT_SAVE_FP is not set, then the stack * frame is saved as shown in diagram (a). Moreover, if OS_TASK_OPT_SAVE_FP is set, then the * FP registers and FP Status Control register are saved in the stack frame. * * (1) When enabling the FP co-processor, make sure to clear bits ASPEN and LSPEN in the * Floating-Point Context Control Register (FPCCR). * * +------------+ +------------+ * | | | | * +------------+ +------------+ * | xPSR | | xPSR | * +------------+ +------------+ * |Return Addr | |Return Addr | * +------------+ +------------+ * | LR(R14) | | LR(R14) | * +------------+ +------------+ * | R12 | | R12 | * +------------+ +------------+ * | R3 | | R3 | * +------------+ +------------+ * | R2 | | R0 | * +------------+ +------------+ * | R1 | | R1 | * +------------+ +------------+ * | R0 | | R0 | * +------------+ +------------+ * | R11 | | R11 | * +------------+ +------------+ * | R10 | | R10 | * +------------+ +------------+ * | R9 | | R9 | * +------------+ +------------+ * | R8 | | R8 | * +------------+ +------------+ * | R7 | | R7 | * +------------+ +------------+ * | R6 | | R6 | * +------------+ +------------+ * | R5 | | R5 | * +------------+ +------------+ * | R4 | | R4 | * +------------+ +------------+ * (a) | FPSCR | * +------------+ * | S31 | * +------------+ * . * . * . * +------------+ * | S1 | +------------+ * | S0 | * +------------+ * (b) * * (4) The SP must be 8-byte aligned in conforming to the Procedure Call Standard for the ARM architecture * * (a) Section 2.1 of the ABI for the ARM Architecture Advisory Note. SP must be 8-byte aligned * on entry to AAPCS-Conforming functions states : * * The Procedure Call Standard for the ARM Architecture [AAPCS] requires primitive * data types to be naturally aligned according to their sizes (for size = 1, 2, 4, 8 bytes). * Doing otherwise creates more problems than it solves. * * In return for preserving the natural alignment of data, conforming code is permitted * to rely on that alignment. To support aligning data allocated on the stack, the stack * pointer (SP) is required to be 8-byte aligned on entry to a conforming function. In * practice this requirement is met if: * * (1) At each call site, the current size of the calling function’s stack frame is a multiple of 8 bytes. * This places an obligation on compilers and assembly language programmers. * * (2) SP is a multiple of 8 when control first enters a program. * This places an obligation on authors of low level OS, RTOS, and runtime library * code to align SP at all points at which control first enters * a body of (AAPCS-conforming) code. * * In turn, this requires the value of SP to be aligned to 0 modulo 8: * * (3) By exception handlers, before calling AAPCS-conforming code. * * (4) By OS/RTOS/run-time system code, before giving control to an application. * * (b) Section 2.3.1 corrective steps from the the SP must be 8-byte aligned on entry * to AAPCS-conforming functions advisory note also states. * * " This requirement extends to operating systems and run-time code for all architecture versions * prior to ARMV7 and to the A, R and M architecture profiles thereafter. Special considerations * associated with ARMV7M are discussed in §2.3.3" * * (1) Even if the SP 8-byte aligment is not a requirement for the ARMv7M profile, the stack is aligned * to 8-byte boundaries to support legacy execution enviroments. * * (c) Section 5.2.1.2 from the Procedure Call Standard for the ARM * architecture states : "The stack must also conform to the following * constraint at a public interface: * * (1) SP mod 8 = 0. The stack must be double-word aligned" * * (d) From the ARM Technical Support Knowledge Base. 8 Byte stack aligment. * * "8 byte stack alignment is a requirement of the ARM Architecture Procedure * Call Standard [AAPCS]. This specifies that functions must maintain an 8 byte * aligned stack address (e.g. 0x00, 0x08, 0x10, 0x18, 0x20) on all external * interfaces. In practice this requirement is met if: * * (1) At each external interface, the current stack pointer * is a multiple of 8 bytes. * * (2) Your OS maintains 8 byte stack alignment on its external interfaces * e.g. on task switches" * ********************************************************************************************************** */ OS_STK *OSTaskStkInit (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT16U opt) { OS_STK *p_stk; p_stk = ptos + 1u; /* Load stack pointer */ /* Align the stack to 8-bytes. */ p_stk = (OS_STK *)((OS_STK)(p_stk) & 0xFFFFFFF8u); /* Registers stacked as if auto-saved on exception */ *(--p_stk) = (OS_STK)0x01000000uL; /* xPSR */ *(--p_stk) = (OS_STK)task; /* Entry Point */ *(--p_stk) = (OS_STK)OS_TaskReturn; /* R14 (LR) */ *(--p_stk) = (OS_STK)0x12121212uL; /* R12 */ *(--p_stk) = (OS_STK)0x03030303uL; /* R3 */ *(--p_stk) = (OS_STK)0x02020202uL; /* R2 */ *(--p_stk) = (OS_STK)0x01010101uL; /* R1 */ *(--p_stk) = (OS_STK)p_arg; /* R0 : argument */ /* Remaining registers saved on process stack */ *(--p_stk) = (OS_STK)0x11111111uL; /* R11 */ *(--p_stk) = (OS_STK)0x10101010uL; /* R10 */ *(--p_stk) = (OS_STK)0x09090909uL; /* R9 */ *(--p_stk) = (OS_STK)0x08080808uL; /* R8 */ *(--p_stk) = (OS_STK)0x07070707uL; /* R7 */ *(--p_stk) = (OS_STK)0x06060606uL; /* R6 */ *(--p_stk) = (OS_STK)0x05050505uL; /* R5 */ *(--p_stk) = (OS_STK)0x04040404uL; /* R4 */ #if (OS_CPU_ARM_FP_EN > 0u) if ((opt & OS_TASK_OPT_SAVE_FP) != (INT16U)0) { *--p_stk = (OS_STK)0x02000000u; /* FPSCR */ /* Initialize S0-S31 floating point registers */ *--p_stk = (OS_STK)0x41F80000u; /* S31 */ *--p_stk = (OS_STK)0x41F00000u; /* S30 */ *--p_stk = (OS_STK)0x41E80000u; /* S29 */ *--p_stk = (OS_STK)0x41E00000u; /* S28 */ *--p_stk = (OS_STK)0x41D80000u; /* S27 */ *--p_stk = (OS_STK)0x41D00000u; /* S26 */ *--p_stk = (OS_STK)0x41C80000u; /* S25 */ *--p_stk = (OS_STK)0x41C00000u; /* S24 */ *--p_stk = (OS_STK)0x41B80000u; /* S23 */ *--p_stk = (OS_STK)0x41B00000u; /* S22 */ *--p_stk = (OS_STK)0x41A80000u; /* S21 */ *--p_stk = (OS_STK)0x41A00000u; /* S20 */ *--p_stk = (OS_STK)0x41980000u; /* S19 */ *--p_stk = (OS_STK)0x41900000u; /* S18 */ *--p_stk = (OS_STK)0x41880000u; /* S17 */ *--p_stk = (OS_STK)0x41800000u; /* S16 */ *--p_stk = (OS_STK)0x41700000u; /* S15 */ *--p_stk = (OS_STK)0x41600000u; /* S14 */ *--p_stk = (OS_STK)0x41500000u; /* S13 */ *--p_stk = (OS_STK)0x41400000u; /* S12 */ *--p_stk = (OS_STK)0x41300000u; /* S11 */ *--p_stk = (OS_STK)0x41200000u; /* S10 */ *--p_stk = (OS_STK)0x41100000u; /* S9 */ *--p_stk = (OS_STK)0x41000000u; /* S8 */ *--p_stk = (OS_STK)0x40E00000u; /* S7 */ *--p_stk = (OS_STK)0x40C00000u; /* S6 */ *--p_stk = (OS_STK)0x40A00000u; /* S5 */ *--p_stk = (OS_STK)0x40800000u; /* S4 */ *--p_stk = (OS_STK)0x40400000u; /* S3 */ *--p_stk = (OS_STK)0x40000000u; /* S2 */ *--p_stk = (OS_STK)0x3F800000u; /* S1 */ *--p_stk = (OS_STK)0x00000000u; /* S0 */ } #endif return (p_stk); } /* ********************************************************************************************************* * TASK SWITCH HOOK * * Description: This function is called when a task switch is performed. This allows you to perform other * operations during a context switch. * * Arguments : none * * Note(s) : 1) Interrupts are disabled during this call. * 2) It is assumed that the global pointer 'OSTCBHighRdy' points to the TCB of the task that * will be 'switched in' (i.e. the highest priority task) and, 'OSTCBCur' points to the * task being switched out (i.e. the preempted task). ********************************************************************************************************* */ #if (OS_CPU_HOOKS_EN > 0u) && (OS_TASK_SW_HOOK_EN > 0u) void OSTaskSwHook (void) { #if (OS_CPU_ARM_FP_EN > 0u) if ((OSTCBCur->OSTCBOpt & OS_TASK_OPT_SAVE_FP) != (INT16U)0) { OS_CPU_FP_Reg_Push(OSTCBCur->OSTCBStkPtr); } if ((OSTCBHighRdy->OSTCBOpt & OS_TASK_OPT_SAVE_FP) != (INT16U)0) { OS_CPU_FP_Reg_Pop(OSTCBHighRdy->OSTCBStkPtr); } #endif #if OS_APP_HOOKS_EN > 0u App_TaskSwHook(); #endif } #endif /* ********************************************************************************************************* * OS_TCBInit() HOOK * * Description: This function is called by OS_TCBInit() after setting up most of the TCB. * * Arguments : ptcb is a pointer to the TCB of the task being created. * * Note(s) : 1) Interrupts may or may not be ENABLED during this call. ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0u void OSTCBInitHook (OS_TCB *ptcb) { #if OS_APP_HOOKS_EN > 0u App_TCBInitHook(ptcb); #else (void)ptcb; /* Prevent compiler warning */ #endif } #endif /* ********************************************************************************************************* * TICK HOOK * * Description: This function is called every tick. * * Arguments : none * * Note(s) : 1) Interrupts may or may not be ENABLED during this call. ********************************************************************************************************* */ #if (OS_CPU_HOOKS_EN > 0u) && (OS_TIME_TICK_HOOK_EN > 0u) void OSTimeTickHook (void) { #if OS_APP_HOOKS_EN > 0u App_TimeTickHook(); #endif #if OS_TMR_EN > 0u OSTmrCtr++; if (OSTmrCtr >= (OS_TICKS_PER_SEC / OS_TMR_CFG_TICKS_PER_SEC)) { OSTmrCtr = 0; OSTmrSignal(); } #endif } #endif /* ********************************************************************************************************* * SYS TICK HANDLER * * Description: Handle the system tick (SysTick) interrupt, which is used to generate the uC/OS-II tick * interrupt. * * Arguments : None. * * Note(s) : 1) This function MUST be placed on entry 15 of the Cortex-M3 vector table. ********************************************************************************************************* */ /* void OS_CPU_SysTickHandler (void) { OS_CPU_SR cpu_sr; OS_ENTER_CRITICAL(); OSIntNesting++; OS_EXIT_CRITICAL(); OSTimeTick(); OSIntExit(); } */ /* ********************************************************************************************************* * INITIALIZE SYS TICK * * Description: Initialize the SysTick. * * Arguments : cnts Number of SysTick counts between two OS tick interrupts. * * Note(s) : 1) This function MUST be called after OSStart() & after processor initialization. ********************************************************************************************************* */ /*void OS_CPU_SysTickInit (INT32U cnts) { INT32U prio; OS_CPU_CM4_NVIC_ST_RELOAD = cnts - 1u; prio = OS_CPU_CM4_NVIC_SHPRI3; prio &= DEF_BIT_FIELD(24, 0); prio |= DEF_BIT_MASK(OS_CPU_CFG_SYSTICK_PRIO, 24); OS_CPU_CM4_NVIC_SHPRI3 = prio; OS_CPU_CM4_NVIC_ST_CTRL |= OS_CPU_CM4_NVIC_ST_CTRL_CLK_SRC | OS_CPU_CM4_NVIC_ST_CTRL_ENABLE; OS_CPU_CM4_NVIC_ST_CTRL |= OS_CPU_CM4_NVIC_ST_CTRL_INTEN; } */