/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * * (c) Copyright 1992-1998, Jean J Labrosse, Plantation, FL * All Rights Reserved * (c) Copyright ARM Limited 1999 All rights reserved * * ARM Specific code * * * File : OS_CPU_CC * * MODIFIED BY : LANCE SIMMS 9/22/10 * Included OSTaskStkInit() ********************************************************************************************************* */ #define OS_CPU_GLOBALS #include "ucos_ii.h" #define BUILD_DATE "Build Date: " __DATE__ "\n" /* ********************************************************************************************************* * 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 * * pdata 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_IIH for OS_TASK_OPT_???) * * 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) : Interrupts are enabled when your task starts executing You can change this by setting the * PSW to 0x0002 instead In this case, interrupts would be disabled upon task startup The * application code would be responsible for enabling interrupts at the beginning of the task * code You will need to modify OSTaskIdle() and OSTaskStat() so that they enable * interrupts Failure to do this will make your system crash! * * LS: 9/22/10 * I based this function definition off of AN-1226, which is supposed to compile on a PXA255 * processor and the text from pg.300-301 in MicroC/OS-II * * The order of registers can be seen easily from the comments on the right to be * R13 (PC), R14 (LR), R12, R11....., R0, CPSR, SPSR * ********************************************************************************************************* */ #define ARM_SYS_MODE 0x0000001F /* This is the value for CSPR that enables interrupts */ OS_STK *OSTaskStkInit(void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt) { OS_STK *stk; opt = opt; /* 'opt' is not used, prevent warning */ stk = ptos; /* Load stack pointer (SP) */ *stk = (OS_STK)task; /* R13 (PC) : Entry Point: Program Counter */ *(--stk) = (INT32U)0x14141414L; /* R14 (LR) */ *(--stk) = (INT32U)0x12121212L; /* R12 */ *(--stk) = (INT32U)0x11111111L; /* R11 */ *(--stk) = (INT32U)0x10101010L; /* R10 */ *(--stk) = (INT32U)0x09090909L; /* R9 */ *(--stk) = (INT32U)0x08080808L; /* R8 */ *(--stk) = (INT32U)0x07070707L; /* R7 */ *(--stk) = (INT32U)0x06060606L; /* R6 */ *(--stk) = (INT32U)0x05050505L; /* R5 */ *(--stk) = (INT32U)0x04040404L; /* R4 */ *(--stk) = (INT32U)0x03030303L; /* R3 */ *(--stk) = (INT32U)0x02020202L; /* R2 */ *(--stk) = (INT32U)0x01010101L; /* R1 */ *(--stk) = (INT32U)pdata; /* R0 */ *(--stk) = (INT32U)ARM_SYS_MODE; /* CPSR (Enable both IRQ and FIQ interrupts) */ return (stk); /* Return the address to which the stack pointer points */ } /*$PAGE*/ /* ********************************************************************************************************* * OS INITIALIZATION HOOK * (BEGINNING) * * Description: This function is called by OSInit() at the beginning of OSInit() * * Arguments : none * * Note(s) : 1) Interrupts should be disabled during this call ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203 void OSInitHookBegin (void) { } #endif /* ********************************************************************************************************* * OS INITIALIZATION HOOK * (END) * * Description: This function is called by OSInit() at the end of OSInit() * * Arguments : none * * Note(s) : 1) Interrupts should be disabled during this call ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0 && OS_VERSION > 203 void OSInitHookEnd (void) { } #endif /*$PAGE*/ /* ********************************************************************************************************* * 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 > 0 void OSTaskCreateHook (OS_TCB *ptcb) { ptcb = ptcb; /* Prevent compiler warning */ } #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 > 0 void OSTaskDelHook (OS_TCB *ptcb) { ptcb = ptcb; /* Prevent compiler warning */ } #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 > 0 && OS_VERSION >= 251 void OSTaskIdleHook (void) { } #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 > 0 void OSTaskStatHook (void) { } #endif /* ********************************************************************************************************* * 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' (ie the highest priority task) and, 'OSTCBCur' points to the * task being switched out (ie the preempted task) * * NOTES: Lance Simms, 9/23/10 * This function was empty to start with and there does not seem to be a reason it should do * anything in our application * ********************************************************************************************************* */ #if OS_CPU_HOOKS_EN > 0 void OSTaskSwHook (void) { } #endif /* ********************************************************************************************************* * OSTCBInit() 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 > 0 && OS_VERSION > 203 void OSTCBInitHook (OS_TCB *ptcb) { ptcb = ptcb; /* Prevent Compiler warning */ } #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 > 0 void OSTimeTickHook (void) { } #endif