Add extra noe to self-modify code bit. And also playing with OC'ing on sandbox.

examples/sandbox/Makefile

@@ -6,7 +6,7 @@ PREFIX:=riscv64-unknown-elf
 
 GPIO_Toggle:=EXAM/GPIO/GPIO_Toggle/User
 
-CH32V003FUN:=../../ch32v003CH32V003FUN
+CH32V003FUN:=../../ch32v003fun
 MINICHLINK:=../../minichlink
 
 CFLAGS:= \
@@ -35,8 +35,11 @@ $(TARGET).bin : $(TARGET).elf
 
 flash : $(TARGET).bin
 	make -C $(MINICHLINK) all
-	$(MINICHLINK)/minichlink -w $< -r
+	$(MINICHLINK)/minichlink -w $< flash -b
+
+monitor : flash
+	$(MINICHLINK)/minichlink -T
+	
 
 clean :
 	rm -rf $(TARGET).elf $(TARGET).bin $(TARGET).hex $(TARGET).lst $(TARGET).map $(TARGET).hex
-

examples/sandbox/sandbox.c

-// Could be defined here, or in the processor defines.
-#define SYSTEM_CORE_CLOCK 48000000
-#define APB_CLOCK SYSTEM_CORE_CLOCK
+/* Small example showing how to use the SWIO programming pin to 
+   do printf through the debug interface */
 
-#include "ch32v00x.h"
+#include "ch32v003fun.h"
 #include <stdio.h>
-#include <string.h>
 
-// Working on WS2812 driving.
+uint32_t count;
+
+
+
+// Tell the compiler to put this code in the .data section.  That
+// will cause the startup code to copy it from flash into RAM where
+// it can be easily modified at runtime.
+void SRAMCode( ) __attribute__(( section(".data"))) __attribute__((noinline)) __attribute__((noreturn));
+void SRAMCode( )
+{
+	asm volatile( 
+"li a0, 0x40011410\n"
+"li a1, (1 | (1<<4))\n"
+"li a2, (1 | (1<<4))<<16\n"
+"1: c.sw a1, 0(a0)\n"
+"   c.sw a2, 0(a0)\n"
+"   j 1b\n" );
+}
 
 int main()
 {
 	SystemInit48HSI();
-	SetupUART( UART_BRR );
+	SetupDebugPrintf();
 
-	int k;
+	// Boost CPU supply.
+	EXTEN->EXTEN_CTR = EXTEN_LDO_TRIM;
 
-	// Enable GPIOD (for debugging)
-	RCC->APB2PCENR |= RCC_APB2Periph_GPIOD;
+	// Enable GPIOs
+	RCC->APB2PCENR |= RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOC;
+
+	// GPIO D0 Push-Pull
 	GPIOD->CFGLR &= ~(0xf<<(4*0));
 	GPIOD->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP)<<(4*0);
-	GPIOD->BSHR = 1; // Turn on GPIOD0
-	GPIOD->BSHR = 1<<16; // Turn off GPIOD0
-
-
-		//DCSR
-		asm volatile("\n\
-			li t0, 0x4\n\
-			csrw 0x7B0, t0\n\
-		");
-
-	while(1)
-	{
-		Delay_Ms( 2 );
-	    *(uint32_t*)(0xe0000100) = 2;  //Hopefully enable debug (dmcontrol .0) --> Doesn't work.
 
-		uint32_t val = *(uint32_t*)0xe00000f4;
-		*(uint32_t*)0xe00000f4 = 0xaabbccdd;
+	// GPIO D4 Push-Pull
+	GPIOD->CFGLR &= ~(0xf<<(4*4));
+	GPIOD->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP)<<(4*4);
 
-		printf( "0xe00000f4: %08x %08x\n", val, __get_dscratch0() );
+	// GPIO C0 Push-Pull
+	GPIOC->CFGLR &= ~(0xf<<(4*0));
+	GPIOC->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP)<<(4*0);
 
-		// Write to dscratch0
-		asm volatile("\n\
-			li t0, 0xa8b8c8d8\n\
-			csrw 0x7B2, t0\n\
-			csrw 0x7B3, t0\n\
-		");
-	}
+	SRAMCode();
 }
 

examples/self_modify_code/self_modify_code.c

@@ -8,7 +8,9 @@
 uint32_t count;
 
 
-
+// Tell the compiler to put this code in the .data section.  That
+// will cause the startup code to copy it from flash into RAM where
+// it can be easily modified at runtime.
 uint32_t ReadCSRSelfModify( uint16_t whichcsr ) __attribute__(( section(".data"))) __attribute__((noinline));
 uint32_t ReadCSRSelfModify( uint16_t whichcsr )
 {
@@ -20,7 +22,7 @@ uint32_t ReadCSRSelfModify( uint16_t whichcsr )
 
 	// We have to put this here to "force" the compiler to order the
 	// instructions in this way.  Otherwise, the compiler will try
-	// to optimize the code and inline the assembly int something where
+	// to optimize the code and inline the assembly into something where
 	// our global handle into assembly code becomes meaningless.
 	// Annoyingly, it has to contain at least one instruction :(
 	asm volatile( "nop" );