Cleaned up pads example, added CMake script for cartrom

5 files changed, 114 insertions, 66 deletions

diff --git a/examples/io/pads/main.c b/examples/io/pads/main.c
index bb56a27..ea7219b 100644
--- a/examples/io/pads/main.c
+++ b/examples/io/pads/main.c
@@ -15,9 +15,12 @@
  * but the code in spi.c can be used to read/write sectors on a memory card and
  * combined with a higher-level filesystem driver for full support.
  *
- * IMPORTANT: this example doesn't work on pcsx-redux, and hasn't yet been
- * tested on real hardware and/or with unofficial controllers. It works on
- * DuckStation and no$psx though.
+ * IMPORTANT: this example hasn't yet been tested on real hardware and/or with
+ * unofficial controllers, which might behave differently at higher poll rates.
+ * Also keep in mind that many emulators emulate controllers and memory cards
+ * inaccurately. It is thus recommended to test controller I/O code extensively
+ * and handle as many edge cases as possible (e.g. partial but valid responses,
+ * zerofilled responses, slow replies) for maximum compatibility.
  */
 
 #include <sys/types.h>
@@ -54,6 +57,10 @@ static const char *const PAD_TYPEIDS[] = {
 #define SCREEN_XRES 320
 #define SCREEN_YRES 240
 
+#define BGCOLOR_R 48
+#define BGCOLOR_G 24
+#define BGCOLOR_B  0
+
 typedef struct {
 	DISPENV  disp;
 	DRAWENV  draw;
@@ -73,14 +80,14 @@ void init_context(CONTEXT *ctx) {
 	db = &(ctx->db[0]);
 	SetDefDispEnv(&(db->disp),           0, 0, SCREEN_XRES, SCREEN_YRES);
 	SetDefDrawEnv(&(db->draw), SCREEN_XRES, 0, SCREEN_XRES, SCREEN_YRES);
-	setRGB0(&(db->draw), 63, 0, 127);
+	setRGB0(&(db->draw), BGCOLOR_R, BGCOLOR_G, BGCOLOR_B);
 	db->draw.isbg = 1;
 	db->draw.dtd  = 1;
 
 	db = &(ctx->db[1]);
 	SetDefDispEnv(&(db->disp), SCREEN_XRES, 0, SCREEN_XRES, SCREEN_YRES);
 	SetDefDrawEnv(&(db->draw),           0, 0, SCREEN_XRES, SCREEN_YRES);
-	setRGB0(&(db->draw), 63, 0, 127);
+	setRGB0(&(db->draw), BGCOLOR_R, BGCOLOR_G, BGCOLOR_B);
 	db->draw.isbg = 1;
 	db->draw.dtd  = 1;
 
@@ -139,13 +146,17 @@ void send_pad_cmd(
 	);
 }
 
-// This callback determines whether a pad that identifies as digital is
-// actually a DualShock in digital mode by checking how it replied to the
-// CONFIG_MODE command.
+// This callback determines whether a pad that identified as digital is
+// actually a DualShock in digital mode by checking if it started identifying
+// as CONFIG_MODE after receiving a configuration command.
 void dualshock_init_cb(uint32_t port, const volatile uint8_t *buff, size_t rx_len) {
-	// Flag the pad as digital-only if it didn't reply.
-	// FIXME: rx_len should be 8 for digital pads, but sometimes it's only 4
-	if (rx_len < 4) {
+	PADTYPE *pad = (PADTYPE *) buff;
+
+	if (
+		(rx_len < 2) ||
+		(pad->raw.prefix != 0x5a) ||
+		(pad->raw.type != PAD_ID_CONFIG_MODE)
+	) {
 		printf("no, pad is digital-only (len = %d)\n", rx_len);
 
 		pad_digital_only[port] = 1;
@@ -154,9 +165,13 @@ void dualshock_init_cb(uint32_t port, const volatile uint8_t *buff, size_t rx_le
 
 	printf("yes, forcing analog mode (len = %d)\n", rx_len);
 
-	// Issue further commands to finish configuring the controller.
+	// Issue further commands to force analog mode on, unlock rumble (not used
+	// in this example) and enable longer responses containing button pressure
+	// readings.
+	// TODO: find out if passing 0x03 instead of 0x02 in PAD_CMD_SET_ANALOG
+	// locks the analog button, as emulated by DuckStation...
 	// https://gist.github.com/scanlime/5042071
-	send_pad_cmd(port, PAD_CMD_SET_ANALOG,      0x01, 0x02, 0); // 0x03 disables analog button...?
+	send_pad_cmd(port, PAD_CMD_SET_ANALOG,      0x01, 0x02, 0);
 	send_pad_cmd(port, PAD_CMD_INIT_PRESSURE,   0x00, 0x00, 0); // Ignored by DualShock 1
 	send_pad_cmd(port, PAD_CMD_REQUEST_CONFIG,  0x00, 0x01, 0);
 	send_pad_cmd(port, PAD_CMD_RESPONSE_CONFIG, 0xff, 0xff, 0); // Ignored by DualShock 1
@@ -179,21 +194,22 @@ void poll_cb(uint32_t port, const volatile uint8_t *buff, size_t rx_len) {
 	// configuration mode. It this fails, it will be flagged as digital-only.
 	// The digital-only flag is reset when the controller is unplugged or stops
 	// returning digital pad responses.
-	if ((pad->raw.prefix == 0x5a) && (pad->raw.type == PAD_ID_DIGITAL)) {
+	if (
+		rx_len &&
+		(pad->raw.prefix == 0x5a) &&
+		(pad->raw.type == PAD_ID_DIGITAL)
+	) {
 		if (!pad_digital_only[port]) {
 			printf("Detecting if pad %d supports config mode... ", port + 1);
 
-			send_pad_cmd(
-				port,
-				PAD_CMD_CONFIG_MODE,
-				0x01,
-				0x00,
-				&dualshock_init_cb
-			);
+			// The pad only identifies as CONFIG_MODE after at least another
+			// command is sent.
+			send_pad_cmd(port, PAD_CMD_CONFIG_MODE, 0x01, 0x00, 0);
+			send_pad_cmd(port, PAD_CMD_CONFIG_MODE, 0x01, 0x00, &dualshock_init_cb);
 		}
 
-	} else if (pad_digital_only[port]) {
-		printf("Clearing digital-only flag for pad %d\n", port + 1);
+	} else {
+		//printf("Clearing digital-only flag for pad %d\n", port + 1);
 
 		pad_digital_only[port] = 0;
 	}
@@ -213,13 +229,7 @@ int main(int argc, const char* argv[]) {
 		FntPrint(-1, "COUNTER=%d", counter++);
 
 		for (uint32_t port = 0; port < 2; port++) {
-			PADTYPE *pad = (PADTYPE *) pad_buff[port];
-
-			// According to nocash docs, there is a hardware bug in DualShock
-			// controllers that causes the prefix byte (normally 0x5a) to turn
-			// into 0x00 if the analog button is pressed after configuration
-			// commands have been used.
-			//if (!pad->raw.prefix != 0x5a) {
+			// TODO.
 			if (!pad_buff_len[port]) {
 				FntPrint(-1, "\n\nPORT %d: NO DEVICE FOUND\n", port + 1);
 				if ((counter % 64) < 32)
@@ -228,26 +238,36 @@ int main(int argc, const char* argv[]) {
 				continue;
 			}
 
-			uint32_t type = pad->raw.type;
-			uint32_t len  = pad->raw.len * 2;
-			if (type == PAD_ID_MULTITAP)
-				len = 32;
+			PADTYPE    *pad = (PADTYPE *) pad_buff[port];
+			PAD_TYPEID type = pad->raw.type;
+
+			// According to nocash docs, there is a hardware bug in DualShock
+			// controllers that causes the prefix byte (normally 0x5a) to turn
+			// into 0x00 if the analog button is pressed after configuration
+			// commands have been used. Thus making sure the prefix is 0x5a
+			// isn't enough to reliably detect pads.
+			/*if ((pad->raw.prefix != 0x5a) && (type != PAD_ID_ANALOG)) {
+				FntPrint(-1, "\n\nPORT %d: INVALID RESPONSE\n", port + 1);
+				if ((counter % 64) < 32)
+					FntPrint(-1, " CHECK CONNECTION...");
+
+				continue;
+			}*/
 
 			FntPrint(
 				-1,
-				"\n\nPORT %d: %s\n TYPE=%d LEN=%d",
+				"\n\nPORT %d: %s (TYPE=%d)\n",
 				port + 1,
 				PAD_TYPEIDS[type],
-				type,
-				len
+				type
 			);
 
 			// Print a hexdump of the payload returned by the pad.
-			for (uint32_t i = 0; i < len; i++)
+			for (uint32_t i = 0; i < pad_buff_len[port]; i++)
 				FntPrint(
 					-1,
-					(i % 8) ? " %02x" : "\n %02x",
-					pad_buff[port][i + 2]
+					((i - 2) % 8) ? " %02x" : "\n %02x",
+					pad_buff[port][i]
 				);
 		}
 
diff --git a/examples/io/pads/spi.c b/examples/io/pads/spi.c
index 4728626..5fc2648 100644
--- a/examples/io/pads/spi.c
+++ b/examples/io/pads/spi.c
@@ -2,9 +2,9 @@
  * PSn00bSDK controller polling example (SPI driver)
  * (C) 2021 spicyjpeg - MPL licensed
  *
- * This is a fairly complete timer driven high-speed SPI driver, with support
- * for sending custom commands (including memory card reads/writes), in about
- * 200 lines of code. Feel free to copypaste and adapt it.
+ * This is a fairly complete timer driven, asynchronous high-speed SPI driver,
+ * with support for sending custom commands (including memory card access), in
+ * about 200 lines of code. Feel free to copypaste and adapt it.
  *
  * The way this works is by maintaining a queue of requests to send, each with
  * its own payload and callback. Timer 2 is configured to trigger an IRQ at
@@ -42,8 +42,12 @@
 #define TIM_VALUE(N)	*((volatile uint32_t *) 0x1f801100 + 4 * (N))
 #define TIM_CTRL(N)		*((volatile uint32_t *) 0x1f801104 + 4 * (N))
 #define TIM_RELOAD(N)	*((volatile uint32_t *) 0x1f801108 + 4 * (N))
-#define JOY_TXRX		*((volatile uint32_t *) 0x1f801040)
-#define JOY_STAT		*((volatile uint32_t *) 0x1f801044)
+
+// IMPORTANT: even though JOY_TXRX is a 32-bit register, it should only be
+// accessed as 8-bit. Reading it as 16 or 32-bit works fine on real hardware,
+// but leads to problems in some emulators.
+#define JOY_TXRX		*((volatile uint8_t *)  0x1f801040)
+#define JOY_STAT		*((volatile uint16_t *) 0x1f801044)
 #define JOY_MODE		*((volatile uint16_t *) 0x1f801048)
 #define JOY_CTRL		*((volatile uint16_t *) 0x1f80104a)
 #define JOY_BAUD		*((volatile uint16_t *) 0x1f80104e)
@@ -142,11 +146,9 @@ static void spi_ack_handler(void) {
 	if (!ctx.rx_len) {
 		// We just sent the first address byte. Obviously the response we
 		// received was read from an open bus, so the SPI port's internal FIFO
-		// must be flushed to ensure we are only going to read valid data from
-		// now on.
-		volatile uint32_t dummy;
-		while (JOY_STAT & 0x0002)
-			dummy = JOY_TXRX;
+		// must be flushed (by performing dummy reads) to ensure we are only
+		// going to read valid data from now on.
+		JOY_TXRX;
 
 	} else if (ctx.rx_len <= SPI_BUFF_LEN) {
 		// If this is not the first byte, put it in the RX buffer.
diff --git a/examples/lowlevel/cartrom/CMakeLists.txt b/examples/lowlevel/cartrom/CMakeLists.txt
new file mode 100644
index 0000000..3e807a3
--- /dev/null
+++ b/examples/lowlevel/cartrom/CMakeLists.txt
@@ -0,0 +1,36 @@
+# PSn00bSDK example CMake script
+# (C) 2021 spicyjpeg - MPL licensed
+
+cmake_minimum_required(VERSION 3.21)
+
+if(NOT DEFINED CMAKE_TOOLCHAIN_FILE AND DEFINED ENV{PSN00BSDK_LIBS})
+	set(CMAKE_TOOLCHAIN_FILE $ENV{PSN00BSDK_LIBS}/cmake/sdk.cmake)
+endif()
+
+project(
+	cartrom
+	LANGUAGES    C ASM
+	VERSION      1.0.0
+	DESCRIPTION  "PSn00bSDK expansion port ROM example"
+	HOMEPAGE_URL "http://lameguy64.net/?page=psn00bsdk"
+)
+
+file(GLOB _sources *.c *.s)
+
+# This example only uses the toolchain (without the rest of the SDK), so the
+# executable has to be created manually and converted into raw binary format
+# (for testing on emulators or flashing to a cheat cartridge).
+add_executable       (cartrom ${_sources})
+target_link_libraries(cartrom psn00bsdk_static_exe)
+set_target_properties(cartrom PROPERTIES PREFIX "" SUFFIX ".elf")
+target_link_options  (cartrom PRIVATE -T${PROJECT_SOURCE_DIR}/rom.ld)
+
+target_include_directories(cartrom PRIVATE ${PROJECT_SOURCE_DIR})
+
+add_custom_command(
+	TARGET     cartrom POST_BUILD
+	COMMAND    ${CMAKE_OBJCOPY} -O binary cartrom.elf cartrom.bin
+	BYPRODUCTS cartrom.bin
+)
+
+install(FILES ${PROJECT_BINARY_DIR}/cartrom.bin TYPE BIN)
diff --git a/examples/lowlevel/cartrom/makefile b/examples/lowlevel/cartrom/makefile
deleted file mode 100644
index 2434685..0000000
--- a/examples/lowlevel/cartrom/makefile
+++ /dev/null
@@ -1,14 +0,0 @@
-PREFIX		= mipsel-unknown-elf-
-
-CC			= $(PREFIX)gcc
-AS			= $(PREFIX)as
-LD			= $(PREFIX)ld
-
-all: rom.o
-	$(LD) --oformat binary -T rom.ld -o cartrom.rom rom.o
-	
-%.o: %.s
-	$(AS) -msoft-float --warn $< -o $@
-	
-clean:
-	rm -f rom.o cartrom.rom
\ No newline at end of file
diff --git a/examples/system/dynlink/display.c b/examples/system/dynlink/display.c
index d8ad3ed..573f17c 100644
--- a/examples/system/dynlink/display.c
+++ b/examples/system/dynlink/display.c
@@ -10,6 +10,10 @@
 #define SCREEN_XRES 320
 #define SCREEN_YRES 240
 
+#define BGCOLOR_R 48
+#define BGCOLOR_G 24
+#define BGCOLOR_B  0
+
 /* Display/GPU context utilities */
 
 void init_context(CONTEXT *ctx) {
@@ -23,14 +27,14 @@ void init_context(CONTEXT *ctx) {
 	db = &(ctx->db[0]);
 	SetDefDispEnv(&(db->disp),           0, 0, SCREEN_XRES, SCREEN_YRES);
 	SetDefDrawEnv(&(db->draw), SCREEN_XRES, 0, SCREEN_XRES, SCREEN_YRES);
-	setRGB0(&(db->draw), 63, 0, 127);
+	setRGB0(&(db->draw), BGCOLOR_R, BGCOLOR_G, BGCOLOR_B);
 	db->draw.isbg = 1;
 	db->draw.dtd  = 1;
 
 	db = &(ctx->db[1]);
 	SetDefDispEnv(&(db->disp), SCREEN_XRES, 0, SCREEN_XRES, SCREEN_YRES);
 	SetDefDrawEnv(&(db->draw),           0, 0, SCREEN_XRES, SCREEN_YRES);
-	setRGB0(&(db->draw), 63, 0, 127);
+	setRGB0(&(db->draw), BGCOLOR_R, BGCOLOR_G, BGCOLOR_B);
 	db->draw.isbg = 1;
 	db->draw.dtd  = 1;