gdb: add original gdb bridge by @redoste

Authored-by: redoste <redoste@redoste.xyz>

CMakeLists.txt

@@ -85,12 +85,19 @@ if(NOT FXLINK_DISABLE_SDL2)
   target_link_libraries(fxlink PkgConfig::sdl2)
 endif()
 
+# fxsdk-gdb-bridge
+add_executable(fxsdk-gdb-bridge fxsdk/gdb-bridge.c)
+target_link_libraries(fxsdk-gdb-bridge libfxlink)
+target_include_directories(fxsdk-gdb-bridge PRIVATE
+  "${SRC}/fxlink/include")
+
 # Install rules
 
 # fxsdk
 install(PROGRAMS "${BIN}/fxsdk.sh" TYPE BIN RENAME fxsdk)
 install(DIRECTORY fxsdk/assets DESTINATION share/fxsdk)
 install(DIRECTORY fxsdk/cmake/ DESTINATION lib/cmake/fxsdk)
+install(TARGETS fxsdk-gdb-bridge)
 # fxgxa, fxg1a
 install(TARGETS fxgxa)
 install(FILES "${BIN}/fxg1a" TYPE BIN)

fxsdk/gdb-bridge.c

@@ -0,0 +1,170 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include <libusb.h>
+
+#include <fxlink/devices.h>
+#include <fxlink/filter.h>
+#include <fxlink/logging.h>
+
+static struct fxlink_device* setup_calc(libusb_context* context) {
+	struct fxlink_filter filter = {
+		.intf_fxlink = true,
+	};
+	delay_t delay = delay_infinite();
+	fxlink_filter_clean_libusb(&filter);
+
+	hlog("calculators");
+	log_("wating for fxlink capable device...\n");
+	struct fxlink_device* dev = fxlink_device_find_wait(context, &filter, &delay);
+	if (!dev) {
+		elog("unable to open fxlink_device\n");
+		return NULL;
+	}
+
+	if (!fxlink_device_claim_fxlink(dev)) {
+		elog("unable to claim fxlink\n");
+		return NULL;
+	}
+
+	return dev;
+}
+
+static int setup_socket(const char* listen_path) {
+	int listen_socket = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (listen_socket < 0) {
+		perror("socket");
+		return -1;
+	}
+
+	struct sockaddr_un listen_address = {
+		.sun_family = AF_UNIX,
+		.sun_path = {0},
+	};
+	strncpy(listen_address.sun_path, listen_path, sizeof(listen_address.sun_path) - 1);
+	if (bind(listen_socket, (struct sockaddr*)&listen_address, sizeof(listen_address)) < 0) {
+		close(listen_socket);
+		perror("bind");
+		return -1;
+	}
+
+	if (listen(listen_socket, 1024) < 0) {
+		close(listen_socket);
+		perror("listen");
+		return -1;
+	}
+
+	hlog("socket");
+	log_("wating for client on \"%s\"...\n", listen_address.sun_path);
+	int client_socket = accept(listen_socket, NULL, NULL);
+	if (client_socket < 0) {
+		close(listen_socket);
+		perror("accept");
+		return -1;
+	}
+	close(listen_socket);
+	return client_socket;
+}
+
+int main(int argc, char* argv[]) {
+	if (argc != 2) {
+		elog("Usage : %s [listen path]\n", argv[0]);
+		return -1;
+	}
+
+	libusb_context* context = NULL;
+	int err = libusb_init(&context);
+	if (err != 0) {
+		elog_libusb(err, "libusb_init");
+		return -1;
+	}
+	struct fxlink_device* dev = setup_calc(context);
+	if (dev == NULL) {
+		return -1;
+	}
+	int client_socket = setup_socket(argv[1]);
+	if (client_socket < 0) {
+		return -1;
+	}
+
+	struct pollfd client_socket_pollfd = {.fd = client_socket, .events = POLLIN};
+	struct fxlink_pollfds fxlink_polled_fds;
+	fxlink_pollfds_track(&fxlink_polled_fds, context);
+
+	if (!fxlink_device_start_bulk_IN(dev)) {
+		elog("unable to start bulk IN trasfer\n");
+		return -1;
+	}
+
+	// TODO : find a way to properly close socket or USB interface when the other side is disconnected
+	int ret = 0;
+	while (1) {
+		int err = fxlink_multipoll(-1, fxlink_polled_fds.fds, fxlink_polled_fds.count,
+					   &client_socket_pollfd, 1,
+					   NULL);
+		if (err < 0) {
+			perror("poll");
+			ret = -1;
+			break;
+		}
+
+		struct timeval zero = {0};
+		libusb_handle_events_timeout(context, &zero);
+		struct fxlink_message* msg;
+		while ((msg = fxlink_device_finish_bulk_IN(dev)) != NULL) {
+			if (!fxlink_message_is_apptype(msg, "gdb", "remote")) {
+				elog("unknown fxlink message type\n");
+				ret = -1;
+				break;
+			}
+			ssize_t send_ret = send(client_socket, msg->data, msg->size, 0);
+			if (send_ret != msg->size) {
+				perror("send");
+				ret = -1;
+				break;
+			}
+			fxlink_message_free(msg, true);
+
+			fxlink_device_start_bulk_IN(dev);
+		}
+
+		if (ret != 0) {
+			break;
+		}
+
+		// We don't want to start a new OUT transfer if another one is still in progress
+		if (!dev->comm->ftransfer_OUT) {
+			int bytes_socket;
+			if (ioctl(client_socket, FIONREAD, &bytes_socket) < 0) {
+				perror("ioctl");
+				ret = -1;
+				break;
+			}
+			if (bytes_socket > 0) {
+				char buf[1024];
+				ssize_t recv_ret = recv(client_socket, buf, sizeof(buf), 0);
+				if (recv_ret < 0) {
+					perror("recv");
+					ret = -1;
+					break;
+				}
+				if (!fxlink_device_start_bulk_OUT(dev, "gdb", "remote", buf, recv_ret, false)) {
+					elog("unable to start bulk OUT trasfer\n");
+					ret = -1;
+					break;
+				}
+			}
+		}
+	}
+
+	fxlink_pollfds_stop(&fxlink_polled_fds);
+	fxlink_device_cleanup(dev);
+	free(dev);
+	libusb_exit(context);
+	return ret;
+}