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; ;******************************************************************************************************** ; uC/OS-II ; The Real-Time Kernel ; ; ; (c) Copyright 2009-2015; Micrium, Inc.; Weston, FL ; All rights reserved. Protected by international copyright laws. ; ; TI C28x Port ; ; File : OS_CPU_A.ASM ; Version : V2.92.11 ; By : JFT ; ; 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 ; application/product. We provide ALL the source code for your convenience and to help you ; 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 : TI C28x ; Mode : C28 Object mode ; Toolchain : TI C/C++ Compiler ;******************************************************************************************************** ;
;******************************************************************************************************** ; INCLUDE FILES ;********************************************************************************************************
;******************************************************************************************************** ; CODE GENERATION DIRECTIVES ;******************************************************************************************************** ; Set text section and reset local labels. .text .newblock
;******************************************************************************************************** ; GET ST0 and ST1 ; ; Description : Wrapper function to get ST0 and ST1 registers from a C function. ; ; Prototypes : INT16U OS_CPU_GetST0(void); ; INT16U OS_CPU_GetST1(void); ;********************************************************************************************************
.asmfunc _OS_CPU_GetST0: PUSH ST0 POP AL LRETR .endasmfunc
.asmfunc _OS_CPU_GetST1: PUSH ST1 POP AL LRETR .endasmfunc
;******************************************************************************************************** ; CRITICAL SECTION METHOD 3 FUNCTIONS ; ; Description: Disable/Enable interrupts by preserving the state of interrupts. Generally speaking you ; would store the state of the interrupt disable flag in the local variable 'cpu_sr' and then ; disable interrupts. 'cpu_sr' is allocated in all of uC/OS-II's functions that need to ; disable interrupts. You would restore the interrupt disable state by copying back 'cpu_sr' ; into the CPU's status register. ; ; Prototypes : OS_CPU_SR OS_CPU_SR_Save(void); ; void OS_CPU_SR_Restore(OS_CPU_SR cpu_sr); ; ; ; Note(s) : 1) These functions are used in general like this: ; ; void Task (void *p_arg) ; { ; #if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */ ; OS_CPU_SR cpu_sr; ; #endif ; ; : ; : ; OS_ENTER_CRITICAL(); /* cpu_sr = OS_CPU_SaveSR(); */ ; : ; : ; OS_EXIT_CRITICAL(); /* OS_CPU_RestoreSR(cpu_sr); */ ; : ; : ; } ;********************************************************************************************************
.asmfunc _OS_CPU_SR_Save: PUSH ST1 DINT POP @AL AND AL, #1 LRETR .endasmfunc
.asmfunc _OS_CPU_SR_Restore: PUSH ST1 POP AR0 AND AR0, #0xFFFE OR AL, AR0 PUSH AL POP ST1 LRETR .endasmfunc
;******************************************************************************************************** ; START MULTITASKING ; void OSStartHighRdy(void) ; Note(s) : 1) This function triggers a PendSV exception (essentially, causes a context switch) to cause ; the first task to start. ; ; 2) OSStartHighRdy() MUST: ; a) Call OSTaskSwHook(). ; b) Set OSRunning to TRUE; ; c) Restore context for OSTCBCurPtr. ; d) IRET into highest ready task. ;******************************************************************************************************** .asmfunc _OSStartHighRdy: ; Call OSTaskSwHook() LCR #_OSTaskSwHook ; Set OSRunning to TRUE. MOVL XAR0, #_OSRunning MOV *AR0, #1 ; Restore context. MOVL XAR0, #_OSTCBCur ; Get the process's SP. MOVL XAR1, *XAR0 MOV AL , *AR1 MOV @SP , AL ; Restore registers. OS_CTX_RESTORE ; IRET into task. IRET .endasmfunc ; Catch start high failure. OSStartHang: SB OSStartHang, UNC
;******************************************************************************************************** ; HANDLE RTOSINT INTERRUPT ; void OS_CPU_RTOSINT_Handler(void) ; ; Note(s) : 1) The RTOSINT interrupt is used to perform a context switch. The C28x core saves the ; ST0, T, ACC, P, AR0, AR1, ST1, DP, IER, DBGSTAT (shadow) registers and the Return ; Address. ; The remaining registers AR1H, AR0H, XAR2..XAR7, XT and RPC are saved by the handler. ; Using RTOSINT means that the switching mechanism is the same for a task or an ISR.
; 2) The context switching RTOSINT handler pseudo-code is: ; a) Save remaining registers on the process stack; ; b) Save the process SP in its TCB, OSTCBCurPtr->OSTCBStkPtr = SP; ; c) Call OSTaskSwHook(); ; d) Get current high priority, OSPrioCur = OSPrioHighRdy; ; e) Get current ready thread TCB, OSTCBCur = OSTCBHighRdy; ; f) Get new process SP from TCB, SP = OSTCBHighRdy->OSTCBStkPtr; ; g) Restore AR1H, AR0H, XAR2..XAR7, XT and RPC registers from the new process stack; ; h) Overwrite the previously saved (at context switch out) IER register with current IER. ; i) Perform exception return which will restore remaining context. ; ; 3) On entry into RTOSINT handler: ; a) The following have been saved on the process stack (by processor): ; ST0, T, ACC, P, AR0, AR1, ST1, DP, IER, DBGSTAT (shadow) registers and the Return ; Address. ; b) OSTCBCurPtr points to the OS_TCB of the task to suspend ; OSTCBHighRdyPtr points to the OS_TCB of the task to resume ; ; 4) This function MUST be placed in entry 16 (for RTOSINT) of the C28x interrupt table. ;********************************************************************************************************
.asmfunc _OS_CPU_RTOSINT_Handler: ; Save registers. OS_CTX_SAVE ; Save SP to current process. MOVL XAR0, #_OSTCBCur ; Get the process's SP. MOVL XAR1, *XAR0 MOV AL , @SP MOV *AR1, AL
ASP ; Align the stack pointer. ; Call OSTaskSwHook. LCR #_OSTaskSwHook NASP ; Restore alignement of the stack pointer.
; OSPrioCur = OSPrioHighRdy MOVL XAR0, #_OSPrioHighRdy MOVL XAR1, #_OSPrioCur MOV ACC, *XAR0 MOV *XAR1, ACC ; OSTCBCur = OSTCBHighRdy MOVL XAR0, #_OSTCBHighRdy MOVL XAR1, #_OSTCBCur MOVL ACC, *XAR0 MOVL *XAR1, ACC ; Get SP from new process. MOVL XAR0, *XAR1 MOV AL , *AR0 MOV @SP , AL
OS_CTX_RESTORE ; Return from interrupt to restore remaining registers. IRET .endasmfunc
;******************************************************************************************************** ; OS-II ASSEMBLY PORT FILE END ;********************************************************************************************************
