富士通UCOS移植心得

wateras1

富士通UCOS移植心得 [复制链接]

富士通9B506移植心得

首先我们要移植UCOS要知道其的软硬件的架构和具体要对那些文件进行改写。UCOS的架构图形如图所示：

从上图我们可以清晰的看到一个UCOS的结构，而我们要改写的内容主要是UC/OS-II Port文件中的OS_CPU.H,OS_CPU_A.ASM,OS_CPU_C.C这三个文件，现在我分别把要改写的内容具体列出来。

第一步修改OS_CPU_C.C

/* Stack grows from HIGH to LOW memory on ARM */

#define OS_STK_GROWTH  1

第二步定义十种数据类型

typedef unsigned char BOOLEAN;

typedef unsigned char INT8U; /* Unsigned 8 bit quantity */

typedef signed char INT8S; /* Signed 8 bit quantity */

typedef unsigned short INT16U; /* Unsigned 16 bit quantity */

typedef signed short INT16S; /* Signed 16 bit quantity */

typedef unsigned int INT32U; /* Unsigned 32 bit quantity */

typedef signed int INT32S; /* Signed 32 bit quantity */ (1)

typedef float FP32; /* Single precision floating point */

typedef double FP64; /* Double precision floating point */

typedef unsigned int OS_STK; /* Each stack entry is 32-bit wide */ (2)

typedef unsigned int OS_CPU_SR; /* Define size of CPU status register (PSR = 32 bits)*/ (3)

（1）       作为ARM CORTEX-M3是一个32位的处理器，无符号短整型和有符号短整型是被申明为INT16U,无符号整型和有符号整型是被定义为INT32U和INT32S

（2）因为堆栈在处理器上是32位的，申明OS_STK为无符号整型

（3）因为这CPU状态寄存器是32位的，申明OS_CPU_SR为无符号整型

第三步：申明宏定义

#define OS_CRITICAL_METHOD 3

#if OS_CRITICAL_METHOD == 3

#define OS_ENTER_CRITICAL() {cpu_sr = OS_CPU_SR_Save();}

#define OS_EXIT_CRITICAL() {OS_CPU_SR_Restore(cpu_sr);} (1)

#endif

#define OS_TASK_SW() OSCtxSw() (2)

修改OS_CPU_A.ASM

写OSStartHighRdy()

OSStartHighRdy

LDR R0, =NVIC_SYSPRI14 ; Set the PendSV exception priority (1)

LDR R1, =NVIC_PENDSV_PRI

STRB R1, [R0]

MOVS R0, #0 ; Set the PSP to 0 for initial context switch call (2)

MSR PSP, R0

LDR R0, =OSRunning ; OSRunning = TRUE (3)

MOVS R1, #1

STRB R1, [R0]

LDR R0, =NVIC_INT_CTRL ; Trigger the PendSV exception (causes context switch)

LDR R1, =NVIC_PENDSVSET

STR R1, [R0]

CPSIE I ; Enable interrupts at processor level (4)

OSStartHang

B OSStartHang ; Should never get here

（1）这功能被OSSTART（）调用去启动最高级优先级任务运行。设置pendSV异常优先级为最低去保障它不被用户打断

（2）设置初始化PSP为0，告诉上下文中断是第一个运行的

（3）设置OSRuning为true去启动多任务调度

（4）PendSV在使能时，PendSV异常可以仅仅被触发

改写OSCtxSw ()

OSCtxSw

LDR R0, =NVIC_INT_CTRL ; Trigger the PendSV exception (causes context switch) (1)

LDR R1, =NVIC_PENDSVSET

STR R1, [R0]

BX LR

OSCtxSw()是被调用是当OS想去执行任务上下文切换时。

OSIntCtxSw ()

OSIntCtxSw

LDR R0, =NVIC_INT_CTRL ; Trigger the PendSV exception (causes context switch) (1)

LDR R1, =NVIC_PENDSVSET

STR R1, [R0]

BX LR

修改OS_CPU_SR_Save () and OS_CPU_SR_Restore ()

OS_CPU_SR_Save

MRS R0, PRIMASK ; Set prio int mask to mask all (except faults) (1)

CPSID I

BX LR

OS_CPU_SR_Restore

MSR PRIMASK, R0 ; (2)

BX LR

改写OS_CPU_PendSVHandler

OS_CPU_PendSVHandler

CPSID I ; Prevent interruption during context switch

MRS R0, PSP ; PSP is process stack pointer (1)

CBZ R0, OS_CPU_PendSVHandler_nosave ; Skip register save the first time

SUBS R0, R0, #0x20 ; Save remaining regs r4-11 on process stack

STM R0, {R4-R11} ;(2)

LDR R1, =OSTCBCur ; OSTCBCur->OSTCBStkPtr = SP; (3)

LDR R1, [R1]

STR R0, [R1] ; R0 is SP of process being switched out

; At this point, entire context of process has been saved

OS_CPU_PendSVHandler_nosave

PUSH {R14} ; Save LR exc_return value

LDR R0, =OSTaskSwHook ; OSTaskSwHook(); (4)

BLX R0

POP {R14}

LDR R0, =OSPrioCur ; OSPrioCur = OSPrioHighRdy; (5)

LDR R1, =OSPrioHighRdy

LDRB R2, [R1]

STRB R2, [R0]

LDR R0, =OSTCBCur ; OSTCBCur = OSTCBHighRdy; (6)

LDR R1, =OSTCBHighRdy

LDR R2, [R1]

STR R2, [R0]

LDR R0, [R2] ; R0 is new process SP; SP = OSTCBHighRdy->OSTCBStkPtr; (7)

LDM R0, {R4-R11} ; Restore r4-11 from new process stack (8)

ADDS R0, R0, #0x20

MSR PSP, R0 ; Load PSP with new process SP

ORR LR, LR, #0x04 ; Ensure exception return uses process stack

CPSIE I

BX LR ; Exception return will restore remaining context (8)

（1）       得到处理器SP，如果0那么就跳到保护单元

（2）       保存寄存器R4-R11在处理器堆栈中

（3）       保存处理器SP到TCB，OSTCBcur->OSTCBstkPtr设置为SP

（4）       调用OSTaskSWHook()

（5）       得到当前最高优先级，OSPrioCut=OSPrioHighRdy

（6）       得到当前预备线程TCB，OSTCBCur=OSTCBHighRdy

（7）       得到新处理器SP从TCB中，SP=OSTCBHighRdy->OSTCBStkPtr

（8）       修复R4-R11从新的处理器堆栈

（9）       执行异常返回它将修复保存的上下文

修改OS_CPU_C.C

OSTaskStkInit

OS_STK *OSTaskStkInit (void (*task)(void *p_arg), void *p_arg, OS_STK *ptos, INT16U opt)

{

OS_STK *stk;

(void)opt; /* 'opt' is not used, prevent warning */

stk = ptos; /* Load stack pointer */

/* Registers stacked as if auto-saved on exception */

/* (1) */

*(stk) = (INT32U)0x01000000L; /* xPSR */

*(--stk) = (INT32U)task; /* Entry Point */

*(--stk) = (INT32U)0xFFFFFFFEL; /* R14 (LR) (init value will cause fault if ever used)*/

*(--stk) = (INT32U)0x12121212L; /* R12 */

*(--stk) = (INT32U)0x03030303L; /* R3 */

*(--stk) = (INT32U)0x02020202L; /* R2 */

*(--stk) = (INT32U)0x01010101L; /* R1 */

*(--stk) = (INT32U)p_arg; /* R0 : argument */

/* Remaining registers saved on process stack */

*(--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 */

return (stk);

}

修改OS_CPU_SysTickInit

void OS_CPU_SysTickInit (void)

{

INT32U cnts;

cnts = OS_CPU_CM3_FREQ / OS_TICKS_PER_SEC; (1)

OS_CPU_CM3_NVIC_ST_RELOAD = (cnts - 1); /* Enable timer. */

OS_CPU_CM3_NVIC_ST_CTRL |= OS_CPU_CM3_NVIC_ST_CTRL_CLK_SRC | OS_CPU_CM3_NVIC_ST_CTRL_ENABLE;(2) /* Enable timer interrupt. */

OS_CPU_CM3_NVIC_ST_CTRL |= OS_CPU_CM3_NVIC_ST_CTRL_INTEN; (3)

}

OS_CPU_SysTickHandler

void OS_CPU_SysTickHandler (void)

{

OS_CPU_SR cpu_sr;

OS_ENTER_CRITICAL(); /* Tell uC/OS-II that we are starting an ISR */

OSIntNesting++; /* (1) */

OS_EXIT_CRITICAL();

OSTimeTick(); /* Call uC/OS-II's OSTimeTick() (2) */

OSIntExit(); /* Tell uC/OS-II that we are leaving the ISR */

}
测试了AD,LCD,PWM,DS18B20,和按键。版本是IAR6.10，本来是想在DIY板子上测试的，可惜烧写时出了问题，没办法只好放在上面弄了，不过代码可以直接上板子上运行。还有一份驱动彩屏的驱动程序，屏控制器为ILI9325.代码已经写好。用的是16位模式。还有几份单独的驱动，也是之前测试通过的，由于感觉比较简单所以之前没公布。

[ 本帖最后由 wateras1 于 2012-8-9 13:37 编辑 ]

17717654801

谢谢分享