📄 os_cpu_c.c
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/*
*********************************************************************************************************
* uC/OS-III
* The Real-Time Kernel
*
*
* (c) Copyright 2009-2010; Micrium, Inc.; Weston, FL
* All rights reserved. Protected by international copyright laws.
*
* ARM Cortex-M4 Port
*
* File : OS_CPU_C.C
* Version : V3.01.2
* By : JJL
* BAN
*
* LICENSING TERMS:
* ---------------
* uC/OS-III 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-III in a commercial application/
* product then, you need to contact Micrium to properly license uC/OS-III for its use in your
* application/product. We provide ALL the source code for your convenience and to help you
* experience uC/OS-III. 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 : ARMv7M Cortex-M4
* Mode : Thumb-2 ISA
* Toolchain : IAR EWARM
*********************************************************************************************************
*/
#define OS_CPU_GLOBALS
#ifdef VSC_INCLUDE_SOURCE_FILE_NAMES
const CPU_CHAR *os_cpu_c__c = "$Id: $";
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* INCLUDE FILES
*********************************************************************************************************
*/
#include <os.h>
/*
*********************************************************************************************************
* 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) : None.
*********************************************************************************************************
*/
void OSIdleTaskHook (void)
{
#if OS_CFG_APP_HOOKS_EN > 0u
if (OS_AppIdleTaskHookPtr != (OS_APP_HOOK_VOID)0) {
(*OS_AppIdleTaskHookPtr)();
}
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* OS INITIALIZATION HOOK
*
* Description: This function is called by OSInit() at the beginning of OSInit().
*
* Arguments : None.
*
* Note(s) : None.
*********************************************************************************************************
*/
void OSInitHook (void)
{
/* 8-byte align the ISR stack. */
OS_CPU_ExceptStkBase = (CPU_STK *)(OSCfg_ISRStkBasePtr + OSCfg_ISRStkSize);
OS_CPU_ExceptStkBase = (CPU_STK *)((CPU_STK)(OS_CPU_ExceptStkBase) & 0xFFFFFFF8);
}
/*$PAGE*/
/*
*********************************************************************************************************
* STATISTIC TASK HOOK
*
* Description: This function is called every second by uC/OS-III's statistics task. This allows your
* application to add functionality to the statistics task.
*
* Arguments : None.
*
* Note(s) : None.
*********************************************************************************************************
*/
void OSStatTaskHook (void)
{
#if OS_CFG_APP_HOOKS_EN > 0u
if (OS_AppStatTaskHookPtr != (OS_APP_HOOK_VOID)0) {
(*OS_AppStatTaskHookPtr)();
}
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* TASK CREATION HOOK
*
* Description: This function is called when a task is created.
*
* Arguments : p_tcb Pointer to the task control block of the task being created.
*
* Note(s) : None.
*********************************************************************************************************
*/
void OSTaskCreateHook (OS_TCB *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
if (OS_AppTaskCreateHookPtr != (OS_APP_HOOK_TCB)0) {
(*OS_AppTaskCreateHookPtr)(p_tcb);
}
#else
(void)p_tcb; /* Prevent compiler warning */
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* TASK DELETION HOOK
*
* Description: This function is called when a task is deleted.
*
* Arguments : p_tcb Pointer to the task control block of the task being deleted.
*
* Note(s) : None.
*********************************************************************************************************
*/
void OSTaskDelHook (OS_TCB *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
if (OS_AppTaskDelHookPtr != (OS_APP_HOOK_TCB)0) {
(*OS_AppTaskDelHookPtr)(p_tcb);
}
#else
(void)p_tcb; /* Prevent compiler warning */
#endif
}
/*$PAGE*/
/*
*********************************************************************************************************
* TASK RETURN HOOK
*
* Description: This function is called if a task accidentally returns. In other words, a task should
* either be an infinite loop or delete itself when done.
*
* Arguments : p_tcb Pointer to the task control block of the task that is returning.
*
* Note(s) : None.
*********************************************************************************************************
*/
void OSTaskReturnHook (OS_TCB *p_tcb)
{
#if OS_CFG_APP_HOOKS_EN > 0u
if (OS_AppTaskReturnHookPtr != (OS_APP_HOOK_TCB)0) {
(*OS_AppTaskReturnHookPtr)(p_tcb);
}
#else
(void)p_tcb; /* Prevent compiler warning */
#endif
}
/*$PAGE*/
/*
**********************************************************************************************************
* INITIALIZE A TASK'S STACK
*
* Description: This function is called by OS_Task_Create() or OSTaskCreateExt() to initialize the stack
* frame of the task being created. This function is highly processor specific.
*
* Arguments : p_task Pointer to the task entry point address.
*
* p_arg Pointer to a user supplied data area that will be passed to the task
* when the task first executes.
*
* p_stk_base Pointer to the base address of the stack.
*
* stk_size Size of the stack, in number of CPU_STK elements.
*
* opt Options used to alter the behavior of OS_Task_StkInit().
* (see OS.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_OPT_TASK_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_OPT_TASK_SAVE_FP is not set, then the stack
* frame is saved as shown in diagram (a). Moreover, if OS_OPT_TASK_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抯 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 ⌨️ 快捷键说明
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