TI中文支持网在LM4F上运行uCosII，而且需要使用FPU主话，移植可以参考M4研讨会PPT3_UCOSII在LM4F中的移植与应用( https://www.deyisupport.com/question_answer/f/57/t/5354.aspx JSW-M4EVB LM4F232H5QD开发板 光盘里有源码),需要修改两个地方就可以使用了，
1. 使能KEIL 的 FPU和MCU 的FPU
2. 修改OSTaskStkInit函数，加入浮点堆栈处理, FPSCR,S15~S0总计18*4=72个字节压栈，还有S31~S16总计 16*4=64字节压栈处理
3. 修改PendSV中断，加入浮点寄存器 S31~S16的压栈和出栈处理
yaksa zhu：
我是这样做的(红色字体部分)，但没有成功，程序跑飞。且编译器提示S16~S31 Bad register name symbol，不得已只好注释掉
请帮忙看看哪里有问题：
1. 使能KEIL 的 FPU和MCU 的FPU
Target Option → Floating Point Hardware→Use FPU
BSP_PreInit()中：
ROM_FPUEnable();
ROM_FPULazyStackingEnable();
2. 修改OSTaskStkInit函数，加入浮点堆栈处理, FPSCR,S15~S0总计18*4=72个字节压栈，还有S31~S16总计 16*4=64字节压栈处理
OSTaskStkInit()中：
… stk = ptos; /* Load stack pointer */
/* Registers stacked as if auto-saved on exception */ // 要使用FPU，需要加入浮点堆栈处理, FPSCR,S15~S0总计18*4=72个字节压栈，还有S31~S16总计 16*4=64字节压栈处理 #if 1 *( stk) = (INT32U)0xccuL; /* No Name Register */ *(–stk) = (INT32U)0xdduL; /* FPSCR */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S15 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S14 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S13 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S12 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S11 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S10 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S9 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S8 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S7 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S6 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S5 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S4 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S3 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S2 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S1 */ *(–stk) = (INT32U)0xAAAAAAAAuL; /* S0 */ #endif
*(–stk) = (INT32U)0x01000000uL; /* xPSR */ *(–stk) = (INT32U)task; /* Entry Point PC */ *(–stk) = (INT32U)0xFFFFFFFEL; /* R14 (LR) (init value will */ /* cause fault if ever used) */ *(–stk) = (INT32U)0x12121212uL; /* R12 */ *(–stk) = (INT32U)0x03030303uL; /* R3 */ *(–stk) = (INT32U)0x02020202uL; /* R2 */ *(–stk) = (INT32U)0x01010101uL; /* R1 */ *(–stk) = (INT32U)p_arg; /* R0 : argument */ /* Remaining registers saved on process stack */ #if 1 *(–stk) = (INT32U)0xBBBBBBBBuL; /* S31 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S30 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S29 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S28 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S27 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S26 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S25 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S24 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S23 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S22 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S21 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S20 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S19 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S18 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S17 */ *(–stk) = (INT32U)0xBBBBBBBBuL; /* S16 */ #endif *(–stk) = (INT32U)0x11111111uL; /* R11 */ *(–stk) = (INT32U)0x10101010uL; /* R10 */
…
3. 修改PendSV中断，加入浮点寄存器 S31~S16的压栈和出栈处理
OSPendSV CPSID I ; Prevent interruption during context switch MRS R0, PSP ; PSP is process stack pointer 栈指针 CBZ R0, OSPendSV_nosave ; 若PSP=0则执行OSPendSV_nosave函数
;SUB R0, R0, #0x40 ; Save remaining regs S16-S31 on process stack ;MOV R1, R0 ;STM R1!, {S16-S31}
SUB R0, R0, #0x20 ; 压栈R4~R11,共8个寄存器,即4字节*8 = 32 = 0x20 MOV R1, R0 STM R1!, {R4-R11} ; 压栈
LDR R1, =OSTCBCur ; R1 = &OSTCBCur LDR R1, [R1] ; R1 = *R1 = *OSTCBCur STR R0, [R1] ; *R1 = R0 (R0 is SP of process being switched out)
; At this point, entire context of process has been savedOSPendSV_nosave PUSH {R14} ; Save LR exc_return value LDR R0, =OSTaskSwHook ; 调用钩子函数OSTaskSwHook(); BLX R0 POP {R14} ; 恢复R14
LDR R0, =OSPrioCur ; 令当前优先级=最高优先级, OSPrioCur = OSPrioHighRdy LDR R1, =OSPrioHighRdy LDRB R2, [R1] STRB R2, [R0]
LDR R0, =OSTCBCur ; 设置当前TCB指针 OSTCBCur = OSTCBHighRdy; LDR R1, =OSTCBHighRdy LDR R2, [R1] STR R2, [R0]
LDR R0, [R2] ; R0 is new process SP; SP = OSTCBHighRdy->OSTCBStkPtr; MOV R1, R0 LDM R1!, {R4-R11} ; Restore r4-11 from new process stack ADDS R0, R0, #0x20 ; R4~R11 Regirst
;VLDM R0, {S16-S31} ; Restore S16-S31 from new process stack ;ADDS R0, R0, #0x40
MSR PSP, R0 ; PSP=R0, Load PSP with new process SP ORR LR, LR, #0x04 ; 确保LR<2>=1,返回到使用进程堆栈 CPSIE I ; 开中断 BX LR ; Exception return will restore remaining context
