Fix on windows + Allow bypass mode for ch32v006

Author: cnlohr

ch32fun/ch32fun.mk

@@ -1,6 +1,9 @@
 # Default prefix for Windows
 ifeq ($(OS),Windows_NT)
 	PREFIX?=riscv64-unknown-elf
+	ifeq ($(shell which $(PREFIX)),)
+		PREFIX:=riscv-none-elf
+	endif
 # Check if riscv64-unknown-elf-gcc exists
 else ifneq ($(shell which riscv64-unknown-elf-gcc),)
 	PREFIX?=riscv64-unknown-elf

minichlink/minichlink.c

@@ -578,7 +578,7 @@ int main( int argc, char ** argv )
 			}
 			case 'w':
 			{
-				struct InternalState * iss = (struct InternalState*)(((struct ProgrammerStructBase*)dev)->internal);
+				//struct InternalState * iss = (struct InternalState*)(((struct ProgrammerStructBase*)dev)->internal);
 				if( argchar[2] != 0 ) goto help;
 				iarg++;
 				argchar = 0; // Stop advancing

minichlink/minichlink.exe

@@ -63,7 +63,12 @@ static void printChipInfo(enum RiscVChip chip) {
 
 static int checkChip(enum RiscVChip chip) {
 	switch(chip) {
+		case CHIP_UNKNOWN:
+		case CHIP_CH32V002:
+		case CHIP_CH32V004:
 		case CHIP_CH32V003:
+		case CHIP_CH32V006:
+		case CHIP_CH32V005:
 		case CHIP_CH32X03x:
 			return 0; // Use direct mode
 		case CHIP_CH32V10x:
@@ -365,21 +370,29 @@ static int LESetupInterface( void * d )
 	// My capture differs in this case: \x05 instead of \x09 -> But does not seem to be needed
 	//wch_link_command( dev, "\x81\x0c\x02\x05\x01", 5, 0, 0, 0 ); //Reply is: 820c0101
 
+	int unknown_chip_fallback = 0;
+
 	// This puts the processor on hold to allow the debugger to run.
 	int already_tried_reset = 0;
 	int is_already_connected = 0;
 	do
 	{
 		// Read DMSTATUS - in case we are a ch32x035, or other chip that does not respond to \x81\x0d\x01\x02.
 		wch_link_command( dev, "\x81\x08\x06\x05\x11\x00\x00\x00\x00\x01", 11, (int*)&transferred, rbuff, 1024 ); // Reply: Ignored, 820d050900300500
-		if( transferred == 9 && rbuff[8] != 0x02 && rbuff[8] != 0x03 && rbuff[8] != 0x00 )
+
+		// There's a couple situations where the older firmware on the official programmer freaks out.
+		// We don't want to inconvenience our users, so just try to work through it by falling back to the minichlink functions.
+		// Part connected.  But the programmer doesn't know what it is.
+		if( transferred == 9 && ( ( rbuff[4] == 0x00 ) || 
+			( rbuff[8] != 0x02 && rbuff[8] != 0x03 && rbuff[8] != 0x00 ) ) )
 		{
 			// Already connected.
 			if( is_already_connected )
 			{
 				printf( "Already Connected\n" );
 				// Still need to read in the data so we can select the correct chip.
 				wch_link_command( dev, "\x81\x0d\x01\x02", 4, (int*)&transferred, rbuff, 1024 ); // ?? this seems to work?
+				unknown_chip_fallback = 1;
 				break;
 			}
 			is_already_connected = 1;
@@ -394,8 +407,11 @@ static int LESetupInterface( void * d )
 				fprintf(stderr, "link error, nothing connected to linker (%d = [%02x %02x %02x %02x]).  Trying to put processor in hold and retrying.\n", transferred, rbuff[0], rbuff[1], rbuff[2], rbuff[3]);
 
 			// Give up if too long
-			if( already_tried_reset > 10 )
-				return -1;
+			if( already_tried_reset > 5 )
+			{
+				unknown_chip_fallback = 1;
+				break;
+			}
 
 			wch_link_multicommands( (libusb_device_handle *)dev, 1, 4, "\x81\x0d\x01\x13" ); // Try forcing reset line low.
 			wch_link_command( (libusb_device_handle *)dev, "\x81\x0d\x01\xff", 4, 0, 0, 0); //Exit programming
@@ -428,6 +444,12 @@ static int LESetupInterface( void * d )
 		return -1;
 	}
 
+	if( unknown_chip_fallback )
+	{
+		printf( "Unknown chip fallback\n" );
+		chip = CHIP_UNKNOWN;
+	}
+
 	printChipInfo(chip);
 
 	iss->target_chip_type = chip;