project start

fw/.gitignore

@@ -6,4 +6,5 @@
 *.lst
 *.map
 *.elf
-*.hex
+*.hex
+compile_commands.json

fw/Makefile

@@ -1,6 +1,6 @@
-all : flash
+all : build
 
-TARGET:=blink
+TARGET:=main
 TARGET_MCU:=CH32X035
 
 include ch32fun/ch32fun/ch32fun.mk

fw/blink.c

@@ -1,9 +0,0 @@
-#include <ch32fun.h>
-
-int main(void) {
-	unsigned int x = 0;
-	while(true) {
-		x = x+1;
-	}
-	return 0;
-}

fw/main.c

@@ -0,0 +1,7 @@
+#include <ch32fun.h>
+
+__attribute__((noreturn)) int main(void)
+{
+	while (1) {
+	}
+}

fw/programmer/src/bitbang_rvswdio.h

@@ -188,7 +188,7 @@ static int InitializeSWDSWIO( struct SWIOState * state )
 		if( MCFReadReg32( state, DMSTATUS, &dmstatus ) != 0 ||
 			MCFReadReg32( state, DMCONTROL, &dmcontrol ) != 0 )
 		{
-			//BB_PRINTF_DEBUG( "Could not read from RVSWD connection\n" );
+			BB_PRINTF_DEBUG( "Could not read from RVSWD connection\n" );
 			state->opmode = 0;
 			continue;
 		}
@@ -198,7 +198,7 @@ static int InitializeSWDSWIO( struct SWIOState * state )
 			( ( dmstatus >> 8 ) & 0xf ) != 0x03 ) ||
 			dmcontrol != 1 )
 		{
-			//BB_PRINTF_DEBUG( "DMSTATUS invalid (Probably no RVSWD chip)\n" );
+			BB_PRINTF_DEBUG( "DMSTATUS invalid (Probably no RVSWD chip)\n" );
 			state->opmode = 0;
 			continue;
 		}
@@ -207,7 +207,7 @@ static int InitializeSWDSWIO( struct SWIOState * state )
 		BB_PRINTF_DEBUG( "Found RVSWD interface\n" );
 		return 0;
 	}
-	//printf( "TIMEOUT\n" );
+	BB_PRINTF_DEBUG( "TIMEOUT\n" );
 	return -55;
 }
 

fw/programmer/src/bitbang_rvswdio_pico.h

@@ -11,13 +11,8 @@
 #define PIN_SWCLK 11
 
 
-// open drain emulation, the pin is set with output '0' and is switched between input or output
-// depending on the wanted value, in the high state the line is pulled high by the pull-up and
-// in the low state the line in forced low
-#define OD_PULL(pin, value) gpio_set_dir((pin), (value) ? GPIO_IN : GPIO_OUT)
-
 // wait time between line transitions
-#define SWD_DELAY() busy_wait_us(1);
+#define SWD_DELAY() busy_wait_us(2);
 
 // microseconds between each register read/write
 #define STOP_WAIT 8
@@ -25,58 +20,33 @@
 // Single wire debug (SWDIO and SWCLK)
 static inline void ConfigureIOForRVSWD(void)
 {
-	// SWDIO, open drain (emulated) with pull-up
+    // SWCLK forced, starts at 1
+	gpio_init(PIN_SWCLK);
+    gpio_set_pulls(PIN_SWCLK, false, false);
+    gpio_put(PIN_SWCLK, 1);
+    gpio_set_dir(PIN_SWCLK, GPIO_OUT);
+
+    // SWDIO, open drain (emulated) with pull-up
 	gpio_init(PIN_SWDIO);
     gpio_set_pulls(PIN_SWDIO, true, false);
-    gpio_put(PIN_SWDIO, 0);
+    gpio_put(PIN_SWDIO, 1);
     gpio_set_dir(PIN_SWDIO, GPIO_IN);
-
-    gpio_init(PIN_SWCLK);
-    gpio_set_pulls(PIN_SWCLK, false, false);
-    gpio_put(PIN_SWCLK, 0);
-    gpio_set_dir(PIN_SWCLK, GPIO_OUT);
 }
 
 
 // Single wire input-output SDI (just SWDIO)
 static inline void ConfigureIOForRVSWIO(void)
 {
-	BB_PRINTF_DEBUG( "TODO: add support for SWIO\n" );
-}
-
-
-static inline void rvswd_start(void)
-{
-    // Start with both lines high
-    gpio_put(PIN_SWCLK, 1);
-    OD_PULL(PIN_SWDIO, 1);
-    //SWD_DELAY();
-
-    // Pull data low
-    OD_PULL(PIN_SWDIO, 0);
-    SWD_DELAY();
-}
-
-
-static inline void rvswd_stop(void)
-{
-    gpio_put(PIN_SWCLK, 0);
-    SWD_DELAY();
-
-    OD_PULL(PIN_SWDIO, 0);
-    SWD_DELAY();
-
-    gpio_put(PIN_SWCLK, 1);
-    SWD_DELAY();
-
-    OD_PULL(PIN_SWDIO, 1);
+	//BB_PRINTF_DEBUG( "TODO: add support for SWIO\n" );
 }
 
 
 void rvswd_write_bit(bool value)
 {
     gpio_put(PIN_SWCLK, 0);
-    OD_PULL(PIN_SWDIO, value);
+    gpio_put(PIN_SWDIO, value);
+    gpio_set_dir(PIN_SWDIO, GPIO_OUT);
+    gpio_set_dir(PIN_SWDIO, GPIO_IN);
     SWD_DELAY();
     gpio_put(PIN_SWCLK, 1);  // Data is sampled on rising edge of clock
     SWD_DELAY();
@@ -85,56 +55,68 @@ void rvswd_write_bit(bool value)
 
 bool rvswd_read_bit(void)
 {
-    OD_PULL(PIN_SWDIO, 0);
+	gpio_put(PIN_SWDIO, 1);
+	gpio_set_dir(PIN_SWDIO, GPIO_IN);
     gpio_put(PIN_SWCLK, 0);
-    OD_PULL(PIN_SWDIO, 1);
     SWD_DELAY();
     bool bit = gpio_get(PIN_SWDIO);
-
     gpio_put(PIN_SWCLK, 1);  // Data is output on rising edge of clock
     SWD_DELAY();
     return bit;
 }
 
 
+static inline void rvswd_stop(void)
+{
+    gpio_put(PIN_SWCLK, 0);
+    SWD_DELAY();
+    gpio_put(PIN_SWDIO, 0);
+    gpio_set_dir(PIN_SWDIO, GPIO_OUT);
+    SWD_DELAY();
+    gpio_put(PIN_SWCLK, 1);
+    SWD_DELAY();
+    gpio_put(PIN_SWDIO, 1);
+    gpio_set_dir(PIN_SWDIO, GPIO_IN);
+}
+
+
 static void MCFWriteReg32( struct SWIOState * state, uint8_t command, uint32_t value )
 {
 	// only supported mode is SWD
 	if (state->opmode != 2) {
-		BB_PRINTF_DEBUG( "TODO: add support for SWIO\n" );
+		//BB_PRINTF_DEBUG( "TODO: add support for SWIO\n" );
 		return;
 	}
 
 	noInterrupts();
-	rvswd_start();
+
+	// start transaction
+	gpio_put(PIN_SWDIO, 0);
+	gpio_set_dir(PIN_SWDIO, GPIO_OUT);
+	SWD_DELAY();
 
     // ADDR HOST
-    bool parity = false;  // This time it's odd parity?
-    for (uint8_t position = 0; position < 7; position++) {
-        bool bit = (command >> (6 - position)) & 1;
+    bool parity = true;
+    for (uint32_t mask = 1<<6; mask; mask >>= 1) {
+        bool bit = !!(command & mask);
+        parity ^= bit;
         rvswd_write_bit(bit);
-        if (bit) parity = !parity;
     }
 
-    // Operation: write
-    rvswd_write_bit(1);
-    parity = !parity;
-
-    // Parity bit (even)
+    rvswd_write_bit(1); // Operation: write
     rvswd_write_bit(parity);
-
     rvswd_read_bit(); // ???
 	rvswd_read_bit(); // Seems only need to be set for first transaction (We are ignoring that though)
 	rvswd_read_bit(); // ???
 	rvswd_write_bit(0); // 0 for register, 1 for value.
 	rvswd_write_bit(0); // ???  Seems to have something to do with halting.
 
-    // Data
+    // DATA
     parity = false;  // This time it's even parity?
-    for (uint8_t position = 0; position < 32; position++) {
-        bool bit = (value >> (31 - position)) & 1;
+    for (uint32_t mask = 1<<31; mask; mask >>= 1) {
+        bool bit = !!(value & mask);
+        parity ^= bit;
         rvswd_write_bit(bit);
-        if (bit) parity = !parity;
     }
 
     // Parity bit
@@ -156,64 +138,60 @@ static int MCFReadReg32( struct SWIOState * state, uint8_t command, uint32_t * v
 {
 	// only supported mode is SWD
 	if (state->opmode != 2) {
-		BB_PRINTF_DEBUG( "TODO: add support for SWIO\n" );
+		//BB_PRINTF_DEBUG( "TODO: add support for SWIO\n" );
 		return -1;
 	}
 
-	bool parity;
-
 	noInterrupts();
-    rvswd_start();
+
+	// start transaction
+	gpio_put(PIN_SWDIO, 0);
+	gpio_set_dir(PIN_SWDIO, GPIO_OUT);
+	SWD_DELAY();
 
     // ADDR HOST
-    parity = false;
-    for (uint8_t position = 0; position < 7; position++) {
-        bool bit = (command >> (6 - position)) & 1;
+    bool parity = false;
+    for (uint8_t mask = 1<<6; mask; mask >>= 1) {
+        bool bit = !!(command & mask);
+        parity ^= bit;
         rvswd_write_bit(bit);
-        if (bit) parity = !parity;
     }
 
-    // Operation: read
-    rvswd_write_bit(0);
-
-    // Parity bit (even)
+    rvswd_write_bit(0); // Operation: read
     rvswd_write_bit(parity);
-
     rvswd_read_bit(); // ??
     rvswd_read_bit(); // ??
     rvswd_read_bit(); // ??
-
     rvswd_write_bit(0); // 0 for register, 1 for value
     rvswd_write_bit(0); // ??? Seems to have something to do with halting?
 
+    // DATA
     *value = 0;
-
-    // Data
     parity = false;
     uint32_t rval = 0;
     for (uint8_t position = 0; position < 32; position++) {
         bool bit = rvswd_read_bit();
         rval <<= 1;
-        if (bit) {
-        	rval |= 1;
-         	parity ^= 1;
-        }
+       	rval |= bit;
+       	parity ^= bit;
     }
     *value = rval;
 
     // Parity bit
     bool parity_read = rvswd_read_bit();
+    if (parity_read != parity) goto read_end;
 
     rvswd_read_bit(); // ??
     rvswd_read_bit(); // ??
     rvswd_read_bit(); // ??
-
-    rvswd_write_bit(1); // 1 for data
+    rvswd_write_bit(1); // 0 for register, 1 for value
 	rvswd_write_bit(0); // ??? Seems to have something to do with halting?
 
     rvswd_stop();
-    interrupts();
 
+read_end:
+    interrupts();
     sleep_us(STOP_WAIT);
+    BB_PRINTF_DEBUG("wrong parity: %d\n", parity_read);
     return (parity == parity_read) ? 0 : -1;
 }

fw/programmer/src/main.cpp

@@ -1,90 +1,59 @@
-	#include "pico/time.h"
-	#include <Arduino.h>
-	#include <SerialUSB.h>
+#include "pico/time.h"
+#include <Arduino.h>
+#include <SerialUSB.h>
 
-	//#define BB_PRINTF_DEBUG(...) Serial.printf(__VA_ARGS__)
-	#define BB_PRINTF_DEBUG(...)
-	#include "bitbang_rvswdio.h"
-	#include "bitbang_rvswdio_pico.h"
+#define BB_PRINTF_DEBUG(...) Serial.printf(__VA_ARGS__)
+//#define BB_PRINTF_DEBUG(...)
+#include "bitbang_rvswdio.h"
+#include "bitbang_rvswdio_pico.h"
 
-	#define PROTOCOL_START     '!'
-	#define PROTOCOL_ACK       '+'
-	#define PROTOCOL_TEST      '?'
-	#define PROTOCOL_POWER_ON  'p'
-	#define PROTOCOL_POWER_OFF 'P'
-	#define PROTOCOL_WRITE_REG 'w'
-	#define PROTOCOL_READ_REG  'r'
+SWIOState state = {.opmode = 2};
 
-	bool last_dtr = false;
-	SWIOState state = {.opmode = 2};
-
-	void setup() {
-	    Serial.begin(115200);
-		Serial.setTimeout(100);
-	    ConfigureIOForRVSWD();
-
-	    // We do NOT block waiting for Serial here,
-	    // we handle the connection dynamically in the loop.
-	}
+void setup() {
+    Serial.begin(115200);
+	Serial.setTimeout(100);
+}
 
 
-	void setup1()
-	{
-		pinMode(LED_BUILTIN, OUTPUT);
-	}
+void setup1()
+{
+	pinMode(LED_BUILTIN, OUTPUT);
+}
 
 
-	void loop() {
-	    // Monitor DTR line to simulate Arduino Reset behavior
-	    bool current_dtr = Serial.dtr();
-	    if (current_dtr && !last_dtr) {
-	        // minichlink just opened the port
-	        ConfigureIOForRVSWD();
-			while (Serial.available() > 0) { Serial.read(); }
-			delay(100);
-	        Serial.write(PROTOCOL_START); // Announce readiness
-	    }
-	    last_dtr = current_dtr;
+void loop() {
+    if (Serial.available() > 0) {
+        char cmd = Serial.read();
+        int ret = 0;
+        uint8_t reg;
 
-	    if (Serial.available() > 0) {
-	        char cmd = Serial.read();
-	        uint8_t reg;
-	        uint32_t val;
-
-	        switch (cmd) {
-	            case PROTOCOL_TEST:
-	                Serial.write(PROTOCOL_ACK);
-	                break;
-	            case PROTOCOL_POWER_ON:
-	                // Not needed for rvswd
-	                sleep_us(10);
-	                Serial.write(PROTOCOL_ACK);
-	                break;
-	            case PROTOCOL_POWER_OFF:
-	                // Not needed for rvswd
-	                sleep_us(10);
-	                Serial.write(PROTOCOL_ACK);
-	                break;
-	            case PROTOCOL_WRITE_REG:
-	                if (Serial.readBytes((char*)&reg, sizeof(uint8_t)) != 1) break;
-	                if (Serial.readBytes((char*)&val, sizeof(uint32_t)) != 4) break;
-	                MCFWriteReg32(&state, reg, val);
-	                Serial.write(PROTOCOL_ACK);
-	                break;
-	            case PROTOCOL_READ_REG:
-	                if (Serial.readBytes((char*)&reg, sizeof(uint8_t)) != 1) break;
-	                MCFReadReg32(&state, reg, &val);
-	                Serial.write((char*)&val, sizeof(uint32_t));
-	                break;
-	        }
-	    }
-	}
+        switch (cmd) {
+        case '!':
+        	state = {};
+        	ret = InitializeSWDSWIO(&state);
+         	if (ret != 0) {
+          		Serial.printf("error initializing SWD: %d\n", ret);
+            	break;
+          	}
+          	ret = DetermineChipTypeAndSectorInfo(&state, NULL);
+            if (ret != 0) {
+          		Serial.printf("failed to determine chip type: %d\n", ret);
+            	break;
+            }
+            Serial.printf("chip type is %x\n", state.target_chip_type);
+        	break;
+        default:
+        	Serial.printf("unknown command '%c'\n", cmd);
+         	break;
+        }
+    }
+}
 
 
-	void loop1()
-	{
-		digitalWrite(LED_BUILTIN, 1);
-		delay(200);
-		digitalWrite(LED_BUILTIN, 0);
-		delay(200);
-	}
+void loop1()
+{
+	digitalWrite(LED_BUILTIN, 1);
+	delay(200);
+	digitalWrite(LED_BUILTIN, 0);
+	delay(200);
+}