Native games: ports of Super Mario 64, Star Fox 64, Ocarina of Time, Mario Kart 64, Majora's Mask and GoldenEye 007

buildroot-external/board/retrostone2/linux.fragment

@@ -50,6 +50,8 @@ CONFIG_INPUT_EVDEV=y
 CONFIG_INPUT_JOYSTICK=y
 CONFIG_JOYSTICK_ADC=y
 CONFIG_JOYSTICK_XPAD=y
+# rsos-gamepad: the built-in controls as one virtual gamepad for native games
+CONFIG_INPUT_UINPUT=y
 CONFIG_INPUT_KEYBOARD=y
 CONFIG_KEYBOARD_GPIO=y
 CONFIG_KEYBOARD_GPIO_POLLED=y

buildroot-external/board/retrostone2/post-build.sh

@@ -49,6 +49,10 @@ mkdir -p "$TARGET/usr/libexec/rsos"
 # (Settings > Power > Memory speed; rsos-boot-ok, tools/rsos-memtest.c).
 "$CC" -O2 -s -Wall -Wextra -Werror -o "$TARGET/usr/libexec/rsos/memtest" \
 	"$BOARD_DIR/tools/rsos-memtest.c"
+# /usr/bin/rsos-gamepad: the built-in controls as one standard gamepad for
+# native games that read SDL game controllers (docs/native-games.md,
+# tools/rsos-gamepad.c; needs CONFIG_INPUT_UINPUT)
+"$CC" -O2 -s -Wall -Wextra -Werror -o "$TARGET/usr/bin/rsos-gamepad" "$BOARD_DIR/tools/rsos-gamepad.c"
 
 # --- The boot loader, for "Install to internal storage" on the Pro
 # (rsos-storage install writes it at 8 KiB on the eMMC): the image's own

buildroot-external/board/retrostone2/tools/rsos-gamepad.c

@@ -0,0 +1,272 @@
+/*
+ * rsos-gamepad - the RetroStone2's built-in controls as one standard gamepad
+ * (uinput), for native games that read SDL game controllers (docs/native-games.md).
+ *
+ * The controls are three evdev devices: "RetroStone2 Buttons" (face, D-pad,
+ * Start/Select, optional C/Z), "RetroStone2 Shoulder Buttons" and the optional
+ * analog stick ("analog-stick", which SDL does not even take for a joystick).
+ * This reads them (no grab: the menu reads them too, for Select+Start) and
+ * writes "RetroStoneOS Gamepad": the Linux gamepad layout by position (bottom
+ * = BTN_SOUTH), C/Z as the stick clicks, the D-pad as hat 0, the stick as
+ * ABS_X/ABS_Y. The launch script starts it in the game's process group, so
+ * the menu stops it with the game, and gives SDL its mapping:
+ *
+ *   SDL_GAMECONTROLLERCONFIG=  RSOS_GAMEPAD_SDL_MAPPING below
+ *   SDL_GAMECONTROLLER_IGNORE_DEVICES=0x0001/0x0001   (the raw gpio-keys)
+ *
+ *   rsos-gamepad [--print-mapping]
+ */
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/input.h>
+#include <linux/uinput.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#define NAME "RetroStoneOS Gamepad"
+#define VENDOR 0x1209   /* pid.codes test vendor: no real device to clash with */
+#define PRODUCT 0x5253  /* "RS" */
+#define VERSION 0x0001
+/* SDL's GUID for it with the name CRC left 0 (matches any name): bus
+ * BUS_VIRTUAL (0x06), vendor, product, version, little-endian 16-bit words;
+ * buttons numbered in key code order (BTN_SOUTH 0x130 ... BTN_THUMBR 0x13e) */
+#define RSOS_GAMEPAD_SDL_MAPPING                                                              \
+	"06000000091200005352000001000000," NAME ",a:b0,b:b1,y:b2,x:b3,leftshoulder:b4,"     \
+	"rightshoulder:b5,lefttrigger:b6,righttrigger:b7,back:b8,start:b9,leftstick:b10,"     \
+	"rightstick:b11,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,leftx:a0,lefty:a1,"    \
+	"platform:Linux,"
+
+#define MAX_SRC 4
+
+static const int out_keys[] = {
+	BTN_SOUTH, BTN_EAST, BTN_NORTH, BTN_WEST, BTN_TL, BTN_TR, BTN_TL2, BTN_TR2,
+	BTN_SELECT, BTN_START, BTN_THUMBL, BTN_THUMBR,
+};
+
+static volatile sig_atomic_t quit;
+
+static void on_signal(int sig)
+{
+	(void)sig;
+	quit = 1;
+}
+
+static void emit(int fd, int type, int code, int value)
+{
+	struct input_event ev;
+
+	memset(&ev, 0, sizeof(ev));
+	ev.type = (unsigned short)type;
+	ev.code = (unsigned short)code;
+	ev.value = value;
+	if (write(fd, &ev, sizeof(ev)) < 0 && errno != EAGAIN)
+		fprintf(stderr, "rsos-gamepad: write: %s\n", strerror(errno));
+}
+
+static int create_pad(void)
+{
+	struct uinput_setup us;
+	struct uinput_abs_setup abs;
+	int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK | O_CLOEXEC);
+
+	if (fd < 0) {
+		fprintf(stderr, "rsos-gamepad: /dev/uinput: %s\n", strerror(errno));
+		return -1;
+	}
+	ioctl(fd, UI_SET_EVBIT, EV_KEY);
+	ioctl(fd, UI_SET_EVBIT, EV_ABS);
+	ioctl(fd, UI_SET_EVBIT, EV_SYN);
+	for (size_t i = 0; i < sizeof(out_keys) / sizeof(out_keys[0]); i++)
+		ioctl(fd, UI_SET_KEYBIT, out_keys[i]);
+	memset(&abs, 0, sizeof(abs));
+	abs.absinfo.minimum = -32767;
+	abs.absinfo.maximum = 32767;
+	abs.code = ABS_X;
+	ioctl(fd, UI_SET_ABSBIT, ABS_X);
+	ioctl(fd, UI_ABS_SETUP, &abs);
+	abs.code = ABS_Y;
+	ioctl(fd, UI_SET_ABSBIT, ABS_Y);
+	ioctl(fd, UI_ABS_SETUP, &abs);
+	abs.absinfo.minimum = -1;
+	abs.absinfo.maximum = 1;
+	abs.code = ABS_HAT0X;
+	ioctl(fd, UI_SET_ABSBIT, ABS_HAT0X);
+	ioctl(fd, UI_ABS_SETUP, &abs);
+	abs.code = ABS_HAT0Y;
+	ioctl(fd, UI_SET_ABSBIT, ABS_HAT0Y);
+	ioctl(fd, UI_ABS_SETUP, &abs);
+
+	memset(&us, 0, sizeof(us));
+	us.id.bustype = BUS_VIRTUAL;
+	us.id.vendor = VENDOR;
+	us.id.product = PRODUCT;
+	us.id.version = VERSION;
+	snprintf(us.name, sizeof(us.name), "%s", NAME);
+	if (ioctl(fd, UI_DEV_SETUP, &us) < 0 || ioctl(fd, UI_DEV_CREATE) < 0) {
+		fprintf(stderr, "rsos-gamepad: cannot create the device: %s\n", strerror(errno));
+		close(fd);
+		return -1;
+	}
+	return fd;
+}
+
+struct src {
+	int fd;
+	bool stick;
+	struct input_absinfo ax, ay;
+};
+
+static int open_sources(struct src *s)
+{
+	DIR *d = opendir("/dev/input");
+	struct dirent *de;
+	int n = 0;
+
+	if (!d)
+		return 0;
+	while ((de = readdir(d)) && n < MAX_SRC) {
+		char path[300], name[128] = "";
+		int fd;
+
+		if (strncmp(de->d_name, "event", 5))
+			continue;
+		snprintf(path, sizeof(path), "/dev/input/%s", de->d_name);
+		fd = open(path, O_RDONLY | O_NONBLOCK | O_CLOEXEC);
+		if (fd < 0)
+			continue;
+		if (ioctl(fd, EVIOCGNAME(sizeof(name) - 1), name) < 0 ||
+		    (strcmp(name, "RetroStone2 Buttons") && strcmp(name, "RetroStone2 Shoulder Buttons") &&
+		     strcmp(name, "analog-stick"))) {
+			close(fd);
+			continue;
+		}
+		memset(&s[n], 0, sizeof(s[n]));
+		s[n].fd = fd;
+		s[n].stick = !strcmp(name, "analog-stick") && ioctl(fd, EVIOCGABS(ABS_X), &s[n].ax) == 0 &&
+			     ioctl(fd, EVIOCGABS(ABS_Y), &s[n].ay) == 0 && s[n].ax.maximum != s[n].ax.minimum &&
+			     s[n].ay.maximum != s[n].ay.minimum;
+		fprintf(stderr, "rsos-gamepad: %s (%s)\n", path, name);
+		n++;
+	}
+	closedir(d);
+	return n;
+}
+
+static bool in_range(int v, const struct input_absinfo *a, bool near_centre)
+{
+	int lo = a->minimum < a->maximum ? a->minimum : a->maximum;
+	int hi = a->minimum < a->maximum ? a->maximum : a->minimum;
+
+	if (near_centre)
+		return abs(v - (lo + (hi - lo) / 2)) <= (hi - lo) / 4;
+	return v >= lo && v <= hi;
+}
+
+/* -32767..32767 from the ADC range */
+static int scale(int v, const struct input_absinfo *a)
+{
+	int lo = a->minimum < a->maximum ? a->minimum : a->maximum;
+	int hi = a->minimum < a->maximum ? a->maximum : a->minimum;
+	long r = ((long)(v - lo) * 65534) / (hi - lo) - 32767;
+
+	return r < -32767 ? -32767 : r > 32767 ? 32767 : (int)r;
+}
+
+int main(int argc, char **argv)
+{
+	struct src src[MAX_SRC];
+	struct pollfd pfd[MAX_SRC];
+	int out, n, sx = 0, sy = 0, hat_x = 0, hat_y = 0;
+	bool fitted = false, dpad[4] = { false };   /* up, down, left, right */
+
+	if (argc > 1 && !strcmp(argv[1], "--print-mapping")) {
+		puts(RSOS_GAMEPAD_SDL_MAPPING);
+		return 0;
+	}
+	signal(SIGTERM, on_signal);
+	signal(SIGINT, on_signal);
+	signal(SIGHUP, on_signal);
+	n = open_sources(src);
+	if (n == 0) {
+		fprintf(stderr, "rsos-gamepad: no built-in controls found\n");
+		return 1;
+	}
+	out = create_pad();
+	if (out < 0)
+		return 1;
+	for (int i = 0; i < n; i++) {
+		pfd[i].fd = src[i].fd;
+		pfd[i].events = POLLIN;
+		if (src[i].stick) {
+			sx = src[i].ax.value;
+			sy = src[i].ay.value;
+		}
+	}
+
+	while (!quit) {
+		if (poll(pfd, (nfds_t)n, 1000) <= 0)
+			continue;
+		for (int i = 0; i < n; i++) {
+			struct input_event ev;
+			bool changed = false;
+
+			if (!(pfd[i].revents & POLLIN))
+				continue;
+			while (read(src[i].fd, &ev, sizeof(ev)) == sizeof(ev)) {
+				if (ev.type == EV_KEY) {
+					int code = ev.code;
+
+					changed = true;
+					switch (code) {
+					case BTN_C: code = BTN_THUMBL; break;
+					case BTN_Z: code = BTN_THUMBR; break;
+					case BTN_DPAD_UP: dpad[0] = ev.value; code = -1; break;
+					case BTN_DPAD_DOWN: dpad[1] = ev.value; code = -1; break;
+					case BTN_DPAD_LEFT: dpad[2] = ev.value; code = -1; break;
+					case BTN_DPAD_RIGHT: dpad[3] = ev.value; code = -1; break;
+					default: break;
+					}
+					if (code >= 0 && ev.value != 2)
+						emit(out, EV_KEY, code, ev.value != 0);
+				} else if (ev.type == EV_ABS && src[i].stick && (ev.code == ABS_X || ev.code == ABS_Y)) {
+					if (ev.code == ABS_X)
+						sx = ev.value;
+					else
+						sy = ev.value;
+					changed = true;
+				}
+			}
+			if (!changed)
+				continue;
+			{
+				int hx = dpad[3] - dpad[2], hy = dpad[1] - dpad[0];
+
+				if (hx != hat_x)
+					emit(out, EV_ABS, ABS_HAT0X, hat_x = hx);
+				if (hy != hat_y)
+					emit(out, EV_ABS, ABS_HAT0Y, hat_y = hy);
+			}
+			if (src[i].stick) {
+				/* the menu's rule (input.c): out of range = not fitted;
+				 * fitted again once both axes read near the centre */
+				if (!in_range(sx, &src[i].ax, false) || !in_range(sy, &src[i].ay, false))
+					fitted = false;
+				else if (!fitted && in_range(sx, &src[i].ax, true) && in_range(sy, &src[i].ay, true))
+					fitted = true;
+				emit(out, EV_ABS, ABS_X, fitted ? scale(sx, &src[i].ax) : 0);
+				emit(out, EV_ABS, ABS_Y, fitted ? scale(sy, &src[i].ay) : 0);
+			}
+			emit(out, EV_SYN, SYN_REPORT, 0);
+		}
+	}
+	ioctl(out, UI_DEV_DESTROY);
+	close(out);
+	return 0;
+}

buildroot-external/configs/retrostone2_defconfig

@@ -77,6 +77,20 @@ BR2_PACKAGE_MESA3D=y
 BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_LIMA=y
 BR2_PACKAGE_MESA3D_OPENGL_EGL=y
 BR2_PACKAGE_MESA3D_OPENGL_ES=y
+# SDL2 on KMS/DRM + GLES2 and ALSA, for native games (docs/native-games.md)
+BR2_PACKAGE_SDL2=y
+BR2_PACKAGE_SDL2_KMSDRM=y
+BR2_PACKAGE_SDL2_OPENGLES=y
+# and the libraries of the libultraship ports (ports/starship, ports/soh: docs/native-games.md)
+BR2_PACKAGE_LIBOGG=y
+BR2_PACKAGE_LIBVORBIS=y
+BR2_PACKAGE_LIBZIP=y
+BR2_PACKAGE_TINYXML2=y
+BR2_PACKAGE_SPDLOG=y
+BR2_PACKAGE_JSON_FOR_MODERN_CPP=y
+BR2_PACKAGE_OPUS=y
+BR2_PACKAGE_OPUSFILE=y
+BR2_PACKAGE_SDL2_NET=y
 BR2_PACKAGE_KMSCUBE=y
 
 # Bring-up tools

buildroot-external/configs/retrostone2_release_defconfig

@@ -77,6 +77,20 @@ BR2_PACKAGE_MESA3D=y
 BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_LIMA=y
 BR2_PACKAGE_MESA3D_OPENGL_EGL=y
 BR2_PACKAGE_MESA3D_OPENGL_ES=y
+# SDL2 on KMS/DRM + GLES2 and ALSA, for native games (docs/native-games.md)
+BR2_PACKAGE_SDL2=y
+BR2_PACKAGE_SDL2_KMSDRM=y
+BR2_PACKAGE_SDL2_OPENGLES=y
+# and the libraries of the libultraship ports (ports/starship, ports/soh: docs/native-games.md)
+BR2_PACKAGE_LIBOGG=y
+BR2_PACKAGE_LIBVORBIS=y
+BR2_PACKAGE_LIBZIP=y
+BR2_PACKAGE_TINYXML2=y
+BR2_PACKAGE_SPDLOG=y
+BR2_PACKAGE_JSON_FOR_MODERN_CPP=y
+BR2_PACKAGE_OPUS=y
+BR2_PACKAGE_OPUSFILE=y
+BR2_PACKAGE_SDL2_NET=y
 BR2_PACKAGE_KMSCUBE=y
 
 # Bring-up tools