/* ********************************************************************************************************* * uC/OS-II * The Real-Time Kernel * * (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL * All Rights Reserved * * * 80x86/80x88 Specific code * LARGE MEMORY MODEL * * Open Watcom 1.6 * * File : OS_CPU_C.C * By : Jean J. Labrosse * Updated By : Miro Samek ********************************************************************************************************* */ #define OS_CPU_GLOBALS #include "ucos_ii.h" #include /* for memcpy() */ /* ********************************************************************************************************* * 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 /* defined in the application 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 /*$PAGE*/ /* ********************************************************************************************************* * 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_II.H 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! ********************************************************************************************************* */ OS_STK *OSTaskStkInit (void (*task)(void *pd), void *pdata, OS_STK *ptos, INT16U opt) { INT16U *stk; struct SREGS sregs; segread(&sregs); /* read the current value of the segment registers */ opt = opt; /* 'opt' is not used, prevent warning */ stk = (INT16U *)ptos; /* Load stack pointer */ *stk-- = (INT16U)FP_SEG(pdata); /* Simulate call to function with argument */ *stk-- = (INT16U)FP_OFF(pdata); *stk-- = (INT16U)FP_SEG(task); *stk-- = (INT16U)FP_OFF(task); *stk-- = (INT16U)0x0202; /* SW = Interrupts enabled */ *stk-- = (INT16U)FP_SEG(task); /* Put pointer to task on top of stack */ *stk-- = (INT16U)FP_OFF(task); *stk-- = (INT16U)0xAAAA; /* AX = 0xAAAA */ *stk-- = (INT16U)0xCCCC; /* CX = 0xCCCC */ *stk-- = (INT16U)0xDDDD; /* DX = 0xDDDD */ *stk-- = (INT16U)0xBBBB; /* BX = 0xBBBB */ *stk-- = (INT16U)0x0000; /* SP = 0x0000 */ *stk-- = (INT16U)0x1111; /* BP = 0x1111 */ *stk-- = (INT16U)0x2222; /* SI = 0x2222 */ *stk-- = (INT16U)0x3333; /* DI = 0x3333 */ *stk-- = (INT16U)0x4444; /* ES = 0x4444 */ *stk = sregs.ds; /* DS = Current value of DS */ return ((OS_STK *)stk); } /*$PAGE*/ /* ********************************************************************************************************* * INITIALIZE A TASK'S STACK FOR FLOATING POINT EMULATION * * Description: This function MUST be called BEFORE calling either OSTaskCreate() or OSTaskCreateExt() in * order to initialize the task's stack to allow the task to use the Borland floating-point * emulation. The returned pointer MUST be used in the task creation call. * * Ex.: OS_STK TaskStk[1000]; * * * void main (void) * { * OS_STK *ptos; * OS_STK *pbos; * INT32U size; * * * OSInit(); * . * . * ptos = &TaskStk[999]; * pbos = &TaskStk[0]; * psize = 1000; * OSTaskStkInit_FPE_x86(&ptos, &pbos, &size); * OSTaskCreate(Task, (void *)0, ptos, 10); * . * . * OSStart(); * } * * Arguments : pptos is the pointer to the task's top-of-stack pointer which would be passed to * OSTaskCreate() or OSTaskCreateExt(). * * ppbos is the pointer to the new bottom of stack pointer which would be passed to * OSTaskCreateExt(). * * psize is a pointer to the size of the stack (in number of stack elements). You * MUST allocate sufficient stack space to leave at least 384 bytes for the * floating-point emulation. * * Returns : The new size of the stack once memory is allocated to the floating-point emulation. * * Note(s) : 1) _SS is a Borland 'pseudo-register' and returns the contents of the Stack Segment (SS) * 2) The pointer to the top-of-stack (pptos) will be modified so that it points to the new * top-of-stack. * 3) The pointer to the bottom-of-stack (ppbos) will be modified so that it points to the new * bottom-of-stack. * 4) The new size of the stack is adjusted to reflect the fact that memory was reserved on * the stack for the floating-point emulation. ********************************************************************************************************* */ /*$PAGE*/ void OSTaskStkInit_FPE_x86 (OS_STK **pptos, OS_STK **ppbos, INT32U *psize) { INT32U lin_tos; /* 'Linear' version of top-of-stack address */ INT32U lin_bos; /* 'Linear' version of bottom-of-stack address */ INT16U seg; INT16U off; INT32U bytes; struct SREGS sregs; segread(&sregs); /* read the current value of the segment registers */ seg = FP_SEG(*pptos); /* Decompose top-of-stack pointer into seg:off */ off = FP_OFF(*pptos); lin_tos = ((INT32U)seg << 4) + (INT32U)off; /* Convert seg:off to linear address */ bytes = *psize * sizeof(OS_STK); /* Determine how many bytes for the stack */ lin_bos = (lin_tos - bytes + 15) & 0xFFFFFFF0L; /* Ensure paragraph alignment for BOS */ seg = (INT16U)(lin_bos >> 4); /* Get new 'normalized' segment */ *ppbos = (OS_STK *)MK_FP(seg, 0x0000); /* Create 'normalized' BOS pointer */ memcpy(*ppbos, MK_FP(sregs.ss, 0), 384u); /* Copy FP emulation memory to task's stack */ bytes = bytes - 16; /* Loose 16 bytes because of alignment */ *pptos = (OS_STK *)MK_FP(seg, (INT16U)bytes); /* Determine new top-of-stack */ *ppbos = (OS_STK *)MK_FP(seg, 384u); /* Determine new bottom-of-stack */ bytes = bytes - 384u; *psize = bytes / sizeof(OS_STK); /* Determine new stack size */ } /*$PAGE*/ /* ********************************************************************************************************* * 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 > 0) && (OS_TASK_SW_HOOK_EN > 0) void OSTaskSwHook (void) { } #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 > 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) && (OS_TIME_TICK_HOOK_EN > 0) /* defined in the application void OSTimeTickHook (void) { } */ #endif