experimental: start working towards a native implementation

src/command.c

@@ -340,7 +340,7 @@ bool cmd_rvswd_scan(target_s *target, int argc, const char **argv)
 #if CONFIG_BMDA == 1
 		scan_result = bmda_rvswd_scan();
 #else
-		scan_result = false;
+		scan_result = rvswd_scan();
 #endif
 	}
 	CATCH () {
@@ -400,7 +400,7 @@ bool cmd_auto_scan(target_s *target, int argc, const char **argv)
 #if CONFIG_BMDA == 1
 				scan_result = bmda_rvswd_scan();
 #else
-				scan_result = false;
+				scan_result = rvswd_scan();
 #endif
 				if (!scan_result)
 					gdb_out("RVSWD scan found no devices.\n");

src/include/rvswd.h

@@ -0,0 +1,44 @@
+/*
+ * This file is part of the Black Magic Debug project.
+ *
+ * Copyright (C) 2011  Black Sphere Technologies Ltd.
+ * Written by Gareth McMullin <[email protected]>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef INCLUDE_RVSWD_H
+#define INCLUDE_RVSWD_H
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+/* Functions interface talking RVSWD */
+typedef struct rvswd_proc {
+	/* Perform a clock_cycles read */
+	uint32_t (*seq_in)(size_t clock_cycles);
+	/* Perform a clock_cycles read + parity */
+	bool (*seq_in_parity)(uint32_t *ret, size_t clock_cycles);
+	/* Perform a clock_cycles write with the provided data */
+	void (*seq_out)(uint32_t tms_states, size_t clock_cycles);
+	/* Perform a clock_cycles write + parity with the provided data */
+	void (*seq_out_parity)(uint32_t tms_states, size_t clock_cycles);
+} rvswd_proc_s;
+
+extern rvswd_proc_s rvswd_proc;
+
+void rvswd_init(void);
+
+#endif /* INCLUDE_RVSWD_H */

src/include/target.h

@@ -49,6 +49,9 @@ bool bmda_rvswd_scan(void);
 #endif
 bool adiv5_swd_scan(uint32_t targetid);
 bool jtag_scan(void);
+// #ifdef PLATFORM_HAS_RVSWD
+bool rvswd_scan(void);
+// #endif
 
 size_t target_foreach(void (*callback)(size_t index, target_s *target, void *context), void *context);
 void target_list_free(void);

src/platforms/common/meson.build

@@ -34,6 +34,7 @@ platform_common_sources = files(
 	'aux_serial.c',
 	'jtagtap.c',
 	'swdptap.c',
+	'rvswd.c',
 	'usb.c',
 	'usb_dfu_stub.c',
 	'usb_serial.c',

src/platforms/common/rvswd.c

@@ -0,0 +1,197 @@
+/*
+ * This file is part of the Black Magic Debug project.
+ *
+ * Copyright (C) 2011  Black Sphere Technologies Ltd.
+ * Written by Gareth McMullin <[email protected]>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* This file implements the SW-DP interface. */
+
+#include "general.h"
+#include "platform.h"
+#include "timing.h"
+#include "rvswd.h"
+#include "maths_utils.h"
+
+// FIXME: reusing the SWD macros for now
+#if !defined(SWDIO_IN_PORT)
+#define SWDIO_IN_PORT SWDIO_PORT
+#endif
+#if !defined(SWDIO_IN_PIN)
+#define SWDIO_IN_PIN SWDIO_PIN
+#endif
+
+// typedef enum swdio_status_e {
+// 	SWDIO_STATUS_FLOAT = 0,
+// 	SWDIO_STATUS_DRIVE
+// } swdio_status_t;
+
+rvswd_proc_s rvswd_proc;
+
+// static void swdptap_turnaround(swdio_status_t dir) __attribute__((optimize(3)));
+// static uint32_t swdptap_seq_in(size_t clock_cycles) __attribute__((optimize(3)));
+// static bool swdptap_seq_in_parity(uint32_t *ret, size_t clock_cycles) __attribute__((optimize(3)));
+// static void swdptap_seq_out(uint32_t tms_states, size_t clock_cycles) __attribute__((optimize(3)));
+// static void swdptap_seq_out_parity(uint32_t tms_states, size_t clock_cycles) __attribute__((optimize(3)));
+
+void rvswd_init(void)
+{
+	// rvswd_proc.seq_in = swdptap_seq_in;
+	// rvswd_proc.seq_in_parity = swdptap_seq_in_parity;
+	// rvswd_proc.seq_out = swdptap_seq_out;
+	// rvswd_proc.seq_out_parity = swdptap_seq_out_parity;
+}
+
+// static void swdptap_turnaround(const swdio_status_t dir)
+// {
+// 	static swdio_status_t olddir = SWDIO_STATUS_FLOAT;
+// 	/* Don't turnaround if direction not changing */
+// 	if (dir == olddir)
+// 		return;
+// 	olddir = dir;
+
+// #ifdef DEBUG_SWD_BITS
+// 	DEBUG_INFO("%s", dir ? "\n-> " : "\n<- ");
+// #endif
+
+// 	if (dir == SWDIO_STATUS_FLOAT) {
+// 		SWDIO_MODE_FLOAT();
+// 	} else
+// 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
+
+// 	for (volatile uint32_t counter = target_clk_divider + 1; counter > 0; --counter)
+// 		continue;
+
+// 	gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 	for (volatile uint32_t counter = target_clk_divider + 1; counter > 0; --counter)
+// 		continue;
+
+// 	if (dir == SWDIO_STATUS_DRIVE) {
+// 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 		SWDIO_MODE_DRIVE();
+// 	}
+// }
+
+// static uint32_t swdptap_seq_in_clk_delay(size_t clock_cycles) __attribute__((optimize(3)));
+
+// static uint32_t swdptap_seq_in_clk_delay(const size_t clock_cycles)
+// {
+// 	uint32_t value = 0;
+// 	for (size_t cycle = 0; cycle < clock_cycles; ++cycle) {
+// 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 		value |= gpio_get(SWDIO_IN_PORT, SWDIO_IN_PIN) ? 1U << cycle : 0U;
+// 		for (volatile uint32_t counter = target_clk_divider; counter > 0; --counter)
+// 			continue;
+// 		gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 		for (volatile uint32_t counter = target_clk_divider; counter > 0; --counter)
+// 			continue;
+// 	}
+// 	gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 	return value;
+// }
+
+// static uint32_t swdptap_seq_in_no_delay(size_t clock_cycles) __attribute__((optimize(3)));
+
+// static uint32_t swdptap_seq_in_no_delay(const size_t clock_cycles)
+// {
+// 	uint32_t value = 0;
+// 	for (size_t cycle = 0; cycle < clock_cycles; ++cycle) {
+// 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 		value |= gpio_get(SWDIO_IN_PORT, SWDIO_IN_PIN) ? 1U << cycle : 0U;
+// 		gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 		__asm__("nop");
+// 	}
+// 	gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 	return value;
+// }
+
+// static uint32_t swdptap_seq_in(size_t clock_cycles)
+// {
+// 	swdptap_turnaround(SWDIO_STATUS_FLOAT);
+// 	if (target_clk_divider != UINT32_MAX)
+// 		return swdptap_seq_in_clk_delay(clock_cycles);
+// 	else // NOLINT(readability-else-after-return)
+// 		return swdptap_seq_in_no_delay(clock_cycles);
+// }
+
+// static bool swdptap_seq_in_parity(uint32_t *ret, size_t clock_cycles)
+// {
+// 	const uint32_t result = swdptap_seq_in(clock_cycles);
+// 	for (volatile uint32_t counter = target_clk_divider + 1; counter > 0; --counter)
+// 		continue;
+
+// 	const bool parity = calculate_odd_parity(result);
+// 	const bool bit = gpio_get(SWDIO_IN_PORT, SWDIO_IN_PIN);
+
+// 	gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 	for (volatile uint32_t counter = target_clk_divider + 1; counter > 0; --counter)
+// 		continue;
+
+// 	*ret = result;
+// 	/* Terminate the read cycle now */
+// 	swdptap_turnaround(SWDIO_STATUS_DRIVE);
+// 	return parity != bit;
+// }
+
+// static void swdptap_seq_out_clk_delay(uint32_t tms_states, size_t clock_cycles) __attribute__((optimize(3)));
+
+// static void swdptap_seq_out_clk_delay(const uint32_t tms_states, const size_t clock_cycles)
+// {
+// 	for (size_t cycle = 0; cycle < clock_cycles; ++cycle) {
+// 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 		gpio_set_val(SWDIO_PORT, SWDIO_PIN, tms_states & (1 << cycle));
+// 		for (volatile uint32_t counter = target_clk_divider; counter > 0; --counter)
+// 			continue;
+// 		gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 		for (volatile uint32_t counter = target_clk_divider; counter > 0; --counter)
+// 			continue;
+// 	}
+// 	gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// }
+
+// static void swdptap_seq_out_no_delay(uint32_t tms_states, size_t clock_cycles) __attribute__((optimize(3)));
+
+// static void swdptap_seq_out_no_delay(const uint32_t tms_states, const size_t clock_cycles)
+// {
+// 	for (size_t cycle = 0; cycle < clock_cycles; ++cycle) {
+// 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// 		gpio_set_val(SWDIO_PORT, SWDIO_PIN, tms_states & (1 << cycle));
+// 		gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 	}
+// 	gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// }
+
+// static void swdptap_seq_out(const uint32_t tms_states, const size_t clock_cycles)
+// {
+// 	swdptap_turnaround(SWDIO_STATUS_DRIVE);
+// 	if (target_clk_divider != UINT32_MAX)
+// 		swdptap_seq_out_clk_delay(tms_states, clock_cycles);
+// 	else
+// 		swdptap_seq_out_no_delay(tms_states, clock_cycles);
+// }
+
+// static void swdptap_seq_out_parity(const uint32_t tms_states, const size_t clock_cycles)
+// {
+// 	const bool parity = calculate_odd_parity(tms_states);
+// 	swdptap_seq_out(tms_states, clock_cycles);
+// 	gpio_set_val(SWDIO_PORT, SWDIO_PIN, parity);
+// 	for (volatile uint32_t counter = target_clk_divider + 1; counter > 0; --counter)
+// 		continue;
+// 	gpio_set(SWCLK_PORT, SWCLK_PIN);
+// 	for (volatile uint32_t counter = target_clk_divider + 1; counter > 0; --counter)
+// 		continue;
+// 	gpio_clear(SWCLK_PORT, SWCLK_PIN);
+// }

src/platforms/hosted/platform.c

@@ -31,6 +31,7 @@
 #include "platform.h"
 #include "jtagtap.h"
 #include "swd.h"
+#include "rvswd.h"
 #include "target.h"
 #include "target_internal.h"
 #include "adiv5.h"
@@ -64,6 +65,7 @@ bmda_probe_s bmda_probe_info;
 #ifndef ENABLE_GPIOD
 jtag_proc_s jtag_proc;
 swd_proc_s swd_proc;
+rvswd_proc_s rvswd_proc;
 #endif
 
 static uint32_t max_frequency = 4000000U;

src/platforms/native/platform.h

@@ -29,6 +29,7 @@
 
 #define PLATFORM_HAS_TRACESWO
 #define PLATFORM_HAS_POWER_SWITCH
+#define PLATFORM_HAS_RVSWD
 
 #if ENABLE_DEBUG == 1
 #define PLATFORM_HAS_DEBUG

src/target/meson.build

@@ -42,6 +42,7 @@ target_common_sources = files(
 	'gdb_reg.c',
 	'jtag_devs.c',
 	'jtag_scan.c',
+	'rvswd_scan.c',
 	'semihosting.c',
 	'sfdp.c',
 	'spi.c',