寄存器保护

tb/sw/src/MstMain.c

@@ -3,6 +3,8 @@
 // #include "uart.h"
 // #include "gpio.h"
 // #include "timer.h"
+#include "custom_ops.S"
+
 
 volatile uint32_t *cdr_status = (uint32_t*)( 0x000 + 0x0 ); //read
 volatile uint32_t *cdr_txLen  = (uint32_t*)( 0x000 + 0x4 ); //write
@@ -46,18 +48,26 @@ void main()
 
 	uint32_t led = 0;
 
+	asm volatile (	
+		"li sp, 0\n"
+		".4byte	0x600600b\n"
+	);
+
+
 	while(1){
 
 		*cdr_softReset = 1; //复位脉冲
 		*cdr_direct = 0;
+		register uint32_t flag;
 
 		asm volatile ( //timer 2s
 			"1:\n"
-			"rdcycle ra\n"
-			"srli ra, ra, 12\n"
-			// "srli ra, ra, 26\n"
-			"andi ra, ra, 0x1\n"
-			"beqz ra, 1b\n"
+			"rdcycle %0\n"
+			"srli %0, %0, 12\n"
+			// "srli %0, %0, 26\n"
+			"andi %0, %0, 0x1\n"
+			"beqz %0, 1b\n"
+			:"+r"(flag)
 		);
 
 		if( led ){
@@ -82,9 +92,10 @@ void main()
 		//等待发送完成标志
 		asm volatile (
 			"1:\n"
-			"andi ra, sp, 0x01\n"
-			"beqz ra, 1b\n"
+			"andi %0, sp, 0x01\n"
+			"beqz %0, 1b\n"
 			"andi sp, sp, 0xFE\n"
+			:"+r"(flag)
 		);
 
 
@@ -95,9 +106,10 @@ void main()
 		//接收第一个包
 		asm volatile (
 			"1:\n"
-			"andi ra, sp, 0x04\n"
-			"beqz ra, 1b\n"
+			"andi %0, sp, 0x04\n"
+			"beqz %0, 1b\n"
 			"andi sp, sp, 0xFB\n"
+			:"+r"(flag)
 		);
 				
 		readDat = *cdr_rxFifo;	
@@ -110,37 +122,42 @@ void main()
 
 		//接收第二个包
 		// asm volatile (
-		// 	"andi ra, sp, 0x08\n"
+		// 	"andi %0, sp, 0x08\n"
 		// 	"1:\n"
-		// 	"bnez ra, 1b\n" //error //速度不够，不校验
+		// 	"bnez %0, 1b\n" //error //速度不够，不校验
+		// :"+r"(flag),
 		// );
 
 		uint32_t temp = *cdr_rxFifo;
 
 		//上行转发负载
 		for( uint32_t i = 0; i < (upRecvLen >> 2); i ++ ){ //一次传4byte
+			register uint32_t upData;
 			asm volatile (
-				"andi ra, sp, 0x80\n"
+				"andi %0, sp, 0x80\n"
 				"1:\n"
-				"bnez ra, 1b\n" //error 速度不够，不再检查接收
-				"lw t1, 0x01c(x0)\n"
+				"bnez %0, 1b\n" //error 速度不够，不再检查接收
+				"lw %1, 0x01c(x0)\n"
+				:"+r"(flag), "+r"(upData)
 			);
 		}
 
 		//CRC
 		asm volatile (
-			"andi ra, sp, 0x08\n"
+			"andi %0, sp, 0x08\n"
 			"1:\n"
-			"bnez ra, 1b\n" //error
+			"bnez %0, 1b\n" //error
+			:"+r"(flag)
 		);
 		uint32_t crc = *cdr_rxFifo; //CRC
 
 		//等待接收完成标志
 		asm volatile (
 			"1:\n"
-			"andi ra, sp, 0x08\n"
-			"beqz ra, 1b\n"
+			"andi %0, sp, 0x08\n"
+			"beqz %0, 1b\n"
 			"andi sp, sp, 0xF7\n"
+			:"+r"(flag)
 		);
 
 		totNum = (upRecvLen >> 3);