Feature: WCH RISC-V support

src/command.c

@@ -56,6 +56,9 @@ static bool cmd_help(target_s *target, int argc, const char **argv);
 
 static bool cmd_jtag_scan(target_s *target, int argc, const char **argv);
 static bool cmd_swd_scan(target_s *target, int argc, const char **argv);
+#ifdef PLATFORM_HAS_RVSWD
+static bool cmd_rvswd_scan(target_s *target, int argc, const char **argv);
+#endif
 static bool cmd_auto_scan(target_s *target, int argc, const char **argv);
 static bool cmd_frequency(target_s *target, int argc, const char **argv);
 static bool cmd_targets(target_s *target, int argc, const char **argv);
@@ -94,6 +97,9 @@ const command_s cmd_list[] = {
 	{"jtag_scan", cmd_jtag_scan, "Scan JTAG chain for devices"},
 	{"swd_scan", cmd_swd_scan, "Scan SWD interface for devices: [TARGET_ID]"},
 	{"swdp_scan", cmd_swd_scan, "Deprecated: use swd_scan instead"},
+#ifdef PLATFORM_HAS_RVSWD
+	{"rvswd_scan", cmd_rvswd_scan, "Scan RVSWD for devices"},
+#endif
 	{"auto_scan", cmd_auto_scan, "Automatically scan all chain types for devices"},
 	{"frequency", cmd_frequency, "set minimum high and low times: [FREQ]"},
 	{"targets", cmd_targets, "Display list of available targets"},
@@ -316,6 +322,52 @@ bool cmd_swd_scan(target_s *target, int argc, const char **argv)
 	return true;
 }
 
+#ifdef PLATFORM_HAS_RVSWD
+bool cmd_rvswd_scan(target_s *target, int argc, const char **argv)
+{
+	(void)target;
+	(void)argc;
+	(void)argv;
+
+	if (platform_target_voltage())
+		gdb_outf("Target voltage: %s\n", platform_target_voltage());
+
+	if (connect_assert_nrst)
+		platform_nrst_set_val(true); /* will be deasserted after attach */
+
+	bool scan_result = false;
+	TRY (EXCEPTION_ALL) {
+#if CONFIG_BMDA == 1
+		scan_result = bmda_rvswd_scan();
+#else
+		scan_result = rvswd_scan();
+#endif
+	}
+	CATCH () {
+	case EXCEPTION_TIMEOUT:
+		gdb_outf("Timeout during scan. Is target stuck in WFI?\n");
+		break;
+	case EXCEPTION_ERROR:
+		gdb_outf("Exception: %s\n", exception_frame.msg);
+		break;
+	default:
+		break;
+	}
+
+	if (!scan_result) {
+		platform_target_clk_output_enable(false);
+		platform_nrst_set_val(false);
+		gdb_out("RVSWD scan failed!\n");
+		return false;
+	}
+
+	cmd_targets(NULL, 0, NULL);
+	platform_target_clk_output_enable(false);
+	morse(NULL, false);
+	return true;
+}
+#endif
+
 bool cmd_auto_scan(target_s *target, int argc, const char **argv)
 {
 	(void)target;
@@ -342,8 +394,18 @@ bool cmd_auto_scan(target_s *target, int argc, const char **argv)
 #else
 			scan_result = adiv5_swd_scan(0);
 #endif
-			if (!scan_result)
+			if (!scan_result) {
 				gdb_out("SWD scan found no devices.\n");
+#ifdef PLATFORM_HAS_RVSWD
+#if CONFIG_BMDA == 1
+				scan_result = bmda_rvswd_scan();
+#else
+				scan_result = rvswd_scan();
+#endif
+				if (!scan_result)
+					gdb_out("RVSWD scan found no devices.\n");
+#endif
+			}
 		}
 	}
 	CATCH () {

src/gdb_packet.c

@@ -81,6 +81,10 @@ void gdb_set_noackmode(bool enable)
 }
 
 #ifndef DEBUG_GDB_IS_NOOP
+/*
+ * To see what packets GDB is seeing you can enable remote protocol debugging with:
+ * `(gdb) set debug remote 1`
+ */
 static void gdb_packet_debug(const char *const func, const gdb_packet_s *const packet)
 {
 	/* Log packet for debugging */

src/include/buffer_utils.h

@@ -84,4 +84,11 @@ static inline uint64_t read_be8(const uint8_t *const buffer, const size_t offset
 		((uint64_t)buffer[offset + 6] << 8U) | buffer[offset + 7];
 }
 
+static inline size_t write_char(char *const buffer, const size_t buffer_size, const size_t offset, const char c)
+{
+	if (buffer && offset < buffer_size)
+		buffer[offset] = c;
+	return offset + 1U;
+}
+
 #endif /*INCLUDE_BUFFER_UTILS_H*/

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 start condition */
+	void (*start)(void);
+	/* Perform a start condition */
+	void (*stop)(void);
+	/* Perform a clock_cycles read */
+	uint32_t (*seq_in)(size_t clock_cycles);
+	/* Perform a clock_cycles write with the provided data */
+	void (*seq_out)(uint32_t dio_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

@@ -45,9 +45,13 @@ typedef struct target_controller target_controller_s;
 #if CONFIG_BMDA == 1
 bool bmda_swd_scan(uint32_t targetid);
 bool bmda_jtag_scan(void);
+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',