Merge remote-tracking branch 'origin/master' into mcuev

refactors all the ugly "pendingX" atomic operations into a single "Event" subsystem/interface thing with two operations

moves all existing code to use this instead

also changes the "bkpt" macro to also indicate unreachable code

arm11/source/arm/gic.c

@@ -19,8 +19,12 @@
 #include <common.h>
 #include <arm.h>
 
+#include <stdatomic.h>
+
 #include "arm/gic.h"
 
+#include "system/event.h"
+
 /* Generic Interrupt Controller Registers */
 #define REG_GIC(cpu, o, t)  REG_ARM_PMR(0x200 + ((cpu) * 0x100) + (o), t)
 
@@ -72,6 +76,7 @@
 #define IRQN_IS_VALID(n)    ((n) < DIC_MAX_IRQ)
 
 static gicIrqHandler gicIrqHandlers[DIC_MAX_IRQ];
+static _Atomic(u32) gicIrqPending[DIC_MAX_IRQ / 32];
 
 static struct {
     u8 tgt;
@@ -106,14 +111,13 @@ static u8 gicGetDefaultIrqCfg(u32 irqn) {
             return gicDefaultIrqCfg[i].mode;
     }
     // TODO: would it be considerably faster to use bsearch?
-
     return GIC_RISINGEDGE_1N;
 }
 
 void gicTopHandler(void)
 {
     while(1) {
-        u32 irqn;
+        u32 irqn, irqsource, index, mask;
 
         /**
             If more than one of these CPUs reads the Interrupt Acknowledge Register at the
@@ -121,16 +125,22 @@ void gicTopHandler(void)
             routine must ensure that only one of them tries to process the interrupt, with the
             others returning after writing the ID to the End of Interrupt Register.
         */
-        irqn = REG_GIC_IRQACK(GIC_THIS_CPU_ALIAS);
+        irqsource = REG_GIC_IRQACK(GIC_THIS_CPU_ALIAS);
 
-        if (irqn == GIC_IRQ_SPURIOUS) // no further processing is needed
+        if (irqsource == GIC_IRQ_SPURIOUS) // no further processing is needed
             break;
 
-        (gicIrqHandlers[irqn & ~IRQN_SRC_MASK])(irqn);
+        irqn = irqsource & ~IRQN_SRC_MASK;
+
+        index = irqn / 32;
+        mask = BIT(irqn % 32);
+        atomic_fetch_or(&gicIrqPending[index], mask);
+
+        (gicIrqHandlers[irqn])(irqsource);
         // if the id is < 16, the source CPU can be obtained from irqn
         // if the handler isn't set, it'll try to branch to 0 and trigger a prefetch abort
 
-        REG_GIC_IRQEND(GIC_THIS_CPU_ALIAS) = irqn;
+        REG_GIC_IRQEND(GIC_THIS_CPU_ALIAS) = irqsource;
     }
 }
 
@@ -152,6 +162,7 @@ void gicGlobalReset(void)
         gicn = MAX_CPU;
 
     // clear the interrupt handler and config table
+    getEventIRQ()->reset();
     memset(gicIrqHandlers, 0, sizeof(gicIrqHandlers));
     memset(gicIrqConfig, 0, sizeof(gicIrqConfig));
 
@@ -263,3 +274,27 @@ void gicTriggerSoftInterrupt(u32 softirq)
 {
     REG_DIC_SOFTINT = softirq;
 }
+
+static void irqEvReset(void) {
+    memset(&gicIrqPending, 0, sizeof(gicIrqPending));
+}
+
+static u32 irqEvTest(u32 param, u32 clear) {
+    u32 index, tstmask, clrmask;
+
+    if (param >= DIC_MAX_IRQ)
+        bkpt;
+    index = param / 32;
+    tstmask = BIT(param % 32);
+    clrmask = clear ? tstmask : 0;
+    return !!(atomic_fetch_and(&gicIrqPending[index], ~clrmask) & tstmask);
+}
+
+static const EventInterface evIRQ = {
+    .reset = irqEvReset,
+    .test = irqEvTest
+};
+
+const EventInterface *getEventIRQ(void) {
+    return &evIRQ;
+}

arm11/source/hw/gpulcd.c

@@ -27,6 +27,8 @@
 #include "hw/mcu.h"
 #include "hw/gpulcd.h"
 
+#include "system/event.h"
+
 static struct
 {
 	u16 lcdIds;            // Bits 0-7 top screen, 8-15 bottom screen.
@@ -112,13 +114,13 @@ unsigned GFX_init(GfxFbFmt mode)
 	TIMER_WaitMS(10);
 	resetLcdsMaybe();
 	MCU_controlLCDPower(2u); // Power on LCDs.
-	if(MCU_waitEvents(0x3Fu<<24) != 2u<<24) __builtin_trap();
+	if(eventWait(getEventMCU(), 0x3Fu<<24, 0x3Fu<<24) != 2u<<24) __builtin_trap();
 
 	waitLcdsReady();
 	REG_LCD_ABL0_LIGHT_PWM = 0x1023E;
 	REG_LCD_ABL1_LIGHT_PWM = 0x1023E;
 	MCU_controlLCDPower(0x28u); // Power on backlights.
-	if(MCU_waitEvents(0x3Fu<<24) != 0x28u<<24) __builtin_trap();
+	if(eventWait(getEventMCU(), 0x3Fu<<24, 0x3Fu<<24) != 0x28u<<24) __builtin_trap();
 	g_gfxState.lcdPower = 0x15; // All on.
 
 	// Make sure the fills finished.
@@ -212,8 +214,9 @@ void GFX_powerOnBacklights(GfxBlight mask)
 
 	mask <<= 1;
 	MCU_controlLCDPower(mask); // Power on backlights.
-	if(MCU_waitEvents(0x3Fu<<24) != (u32)mask<<24)
+	eventWait(getEventMCU(), 0x3F<<24, 0x3F<<24);
-		__builtin_trap();
+	/*if(mcuEventWait(0x3Fu<<24) != (u32)mask<<24)
+		__builtin_trap();*/
 }
 
 void GFX_powerOffBacklights(GfxBlight mask)
@@ -221,8 +224,9 @@ void GFX_powerOffBacklights(GfxBlight mask)
 	g_gfxState.lcdPower &= ~mask;
 
 	MCU_controlLCDPower(mask); // Power off backlights.
-	if(MCU_waitEvents(0x3Fu<<24) != (u32)mask<<24)
+	eventWait(getEventMCU(), 0x3F<<24, 0x3F<<24);
-		__builtin_trap();
+	/*if(mcuEventWait(0x3Fu<<24) != (u32)mask<<24)
+		__builtin_trap();*/
 }
 
 u8 GFX_getBrightness(void)

arm11/source/hw/hid.c

@@ -52,7 +52,7 @@ u64 HID_GetState(void)
 
 	CODEC_Get(&codec);
 
-	ret = REG_HID | MCU_GetSpecialHID();
+	ret = REG_HID | mcuGetSpecialHID();
 	if (!(ret & BUTTON_ARROW))
 		ret |= HID_ConvertCPAD(codec.cpad_x, codec.cpad_y);
 

arm11/source/hw/mcu.c

@@ -20,40 +20,37 @@
 #include <types.h>
 #include <arm.h>
 
+#include <stdatomic.h>
+
 #include "arm/timer.h"
 
 #include "hw/gpio.h"
 #include "hw/gpulcd.h"
 #include "hw/mcu.h"
 
-enum {
+#include "system/event.h"
-	MCU_PWR_BTN = 0,
+
-	MCU_PWR_HOLD = 1,
+#define MCUEV_HID_MASK ( \
-	MCU_HOME_BTN = 2,
+	MCUEV_HID_PWR_DOWN | MCUEV_HID_PWR_HOLD | \
-	MCU_HOME_LIFT = 3,
+	MCUEV_HID_HOME_DOWN | MCUEV_HID_HOME_UP | MCUEV_HID_WIFI_SWITCH)
-	MCU_WIFI_SWITCH = 4,
-	MCU_SHELL_CLOSE = 5,
-	MCU_SHELL_OPEN = 6,
-	MCU_VOL_SLIDER = 22,
-};
 
 enum {
-	REG_VOL_SLIDER = 0x09,
+	MCUREG_VOLUME_SLIDER = 0x09,
 
-	REG_BATTERY_LEVEL = 0x0B,
+	MCUREG_BATTERY_LEVEL = 0x0B,
-	REG_CONSOLE_STATE = 0x0F,
+	MCUREG_CONSOLE_STATE = 0x0F,
 
-	REG_INT_MASK = 0x10,
+	MCUREG_INT_MASK = 0x10,
-	REG_INT_EN = 0x18,
+	MCUREG_INT_EN = 0x18,
 
-	REG_LCD_STATE = 0x22,
+	MCUREG_LCD_STATE = 0x22,
 
-	REG_LED_WIFI = 0x2A,
+	MCUREG_LED_WIFI = 0x2A,
-	REG_LED_CAMERA = 0x2B,
+	MCUREG_LED_CAMERA = 0x2B,
-	REG_LED_SLIDER = 0x2C,
+	MCUREG_LED_SLIDER = 0x2C,
-	REG_LED_NOTIF = 0x2D,
+	MCUREG_LED_STATUS = 0x2D,
 
-	REG_RTC = 0x30,
+	MCUREG_RTC = 0x30,
 };
 
 typedef struct {
@@ -64,47 +61,73 @@ typedef struct {
 	u32 red[8];
 	u32 green[8];
 	u32 blue[8];
-} PACKED_STRUCT MCU_NotificationLED;
+} PACKED_STRUCT mcuStatusLED;
 
-static u8 cached_volume_slider = 0;
+static u8 volumeSliderValue;
-static u32 spec_hid = 0, shell_state = 0;
+static u32 shellState;
+static _Atomic(u32) pendingEvents;
 
-static void MCU_UpdateVolumeSlider(void)
+static void mcuEventUpdate(void)
 {
-	cached_volume_slider = MCU_ReadReg(REG_VOL_SLIDER);
+	u32 mask;
+
+	// lazily update the mask on each test attempt
+	if (!getEventIRQ()->test(MCU_INTERRUPT, true))
+		return;
+
+	// reading the pending mask automagically acknowledges
+	// the interrupts so all of them must be processed in one go
+	mcuReadRegBuf(MCUREG_INT_MASK, (u8*)&mask, sizeof(mask));
+
+	if (mask & MCUEV_HID_VOLUME_SLIDER)
+		volumeSliderValue = mcuReadReg(MCUREG_VOLUME_SLIDER);
+
+	if (mask & MCUEV_HID_SHELL_OPEN) {
+		mcuResetLEDs();
+		shellState = SHELL_OPEN;
+	}
+
+	if (mask & MCUEV_HID_SHELL_CLOSE) {
+		shellState = SHELL_CLOSED;
+	}
+
+	atomic_fetch_or(&pendingEvents, mask);
 }
 
-static void MCU_UpdateShellState(bool open)
+u8 mcuGetVolumeSlider(void)
 {
-	shell_state = open ? SHELL_OPEN : SHELL_CLOSED;
+	mcuEventUpdate();
+	return volumeSliderValue;
 }
 
-u8 MCU_GetVolumeSlider(void)
+u32 mcuGetSpecialHID(void)
 {
-	return cached_volume_slider;
+	u32 ret = 0, pend = getEventMCU()->test(MCUEV_HID_MASK, MCUEV_HID_MASK);
+
+	// hopefully gets unrolled
+	if (pend & (MCUEV_HID_PWR_DOWN | MCUEV_HID_PWR_HOLD))
+		ret |= BUTTON_POWER;
+	if (pend & MCUEV_HID_HOME_DOWN)
+		ret |= BUTTON_HOME;
+	if (pend & MCUEV_HID_HOME_UP)
+		ret &= ~BUTTON_HOME;
+	return ret | shellState;
 }
 
-u32 MCU_GetSpecialHID(void)
+void mcuSetStatusLED(u32 period_ms, u32 color)
-{
-	u32 ret = spec_hid | shell_state;
-	spec_hid = 0;
-	return ret;
-}
-
-void MCU_SetNotificationLED(u32 period_ms, u32 color)
 {
 	u32 r, g, b;
-	MCU_NotificationLED led_state;
+	mcuStatusLED ledState;
 
 	// handle proper non-zero periods
 	// so small the hardware can't handle it
 	if (period_ms != 0 && period_ms < 63)
 		period_ms = 63;
 
-	led_state.delay = (period_ms * 0x10) / 1000;
+	ledState.delay = (period_ms * 0x10) / 1000;
-	led_state.smoothing = 0x40;
+	ledState.smoothing = 0x40;
-	led_state.loop_delay = 0x10;
+	ledState.loop_delay = 0x10;
-	led_state.unk = 0;
+	ledState.unk = 0;
 
 	// all colors look like 0x00ZZ00ZZ
 	// in order to alternate between
@@ -112,93 +135,65 @@ void MCU_SetNotificationLED(u32 period_ms, u32 color)
 	r = (color >> 16) & 0xFF;
 	r |= r << 16;
 	for (int i = 0; i < 8; i++)
-		led_state.red[i] = r;
+		ledState.red[i] = r;
 
 	g = (color >> 8) & 0xFF;
 	g |= g << 16;
 	for (int i = 0; i < 8; i++)
-		led_state.green[i] = g;
+		ledState.green[i] = g;
 
 	b = color & 0xFF;
 	b |= b << 16;
 	for (int i = 0; i < 8; i++)
-		led_state.blue[i] = b;
+		ledState.blue[i] = b;
 
-	MCU_WriteRegBuf(REG_LED_NOTIF, (const u8*)&led_state, sizeof(led_state));
+	mcuWriteRegBuf(MCUREG_LED_STATUS, (const u8*)&ledState, sizeof(ledState));
 }
 
-void MCU_ResetLED(void)
+void mcuResetLEDs(void)
 {
-	MCU_WriteReg(REG_LED_WIFI, 0);
+	mcuWriteReg(MCUREG_LED_WIFI, 0);
-	MCU_WriteReg(REG_LED_CAMERA, 0);
+	mcuWriteReg(MCUREG_LED_CAMERA, 0);
-	MCU_WriteReg(REG_LED_SLIDER, 0);
+	mcuWriteReg(MCUREG_LED_SLIDER, 0);
-	MCU_SetNotificationLED(0, 0);
+	mcuSetStatusLED(0, 0);
 }
 
-void MCU_HandleInterrupts(u32 __attribute__((unused)) irqn)
+void mcuReset(void)
 {
-	u32 ints;
+	u32 intmask = 0;
 
-	// Reading the pending mask automagically acknowledges
+	atomic_init(&pendingEvents, 0);
-	// the interrupts so all of them must be processed in one go
-	MCU_ReadRegBuf(REG_INT_MASK, (u8*)&ints, sizeof(ints));
 
-	while(ints != 0) {
+	// set register mask and clear any pending registers
-		u32 mcu_int_id = 31 - __builtin_clz(ints);
+	mcuWriteRegBuf(MCUREG_INT_EN, (const u8*)&intmask, sizeof(intmask));
+	mcuReadRegBuf(MCUREG_INT_MASK, (u8*)&intmask, sizeof(intmask));
 
-		switch(mcu_int_id) {
+	mcuResetLEDs();
-			case MCU_PWR_BTN:
-			case MCU_PWR_HOLD:
-				spec_hid |= BUTTON_POWER;
-				break;
 
-			case MCU_HOME_BTN:
+	volumeSliderValue = mcuReadReg(MCUREG_VOLUME_SLIDER);
-				spec_hid |= BUTTON_HOME;
+	shellState = SHELL_OPEN;
-				break;
+	// assume the shell is always open on boot
-
+	// knowing the average 3DS user, there will be plenty
-			case MCU_HOME_LIFT:
+	// of laughs when this comes back to bite us in the rear
-				spec_hid &= ~BUTTON_HOME;
-				break;
-
-			case MCU_WIFI_SWITCH:
-				spec_hid |= BUTTON_WIFI;
-				break;
-
-			case MCU_SHELL_OPEN:
-				MCU_UpdateShellState(true);
-				MCU_ResetLED();
-				break;
-
-			case MCU_SHELL_CLOSE:
-				MCU_UpdateShellState(false);
-				break;
-
-			case MCU_VOL_SLIDER:
-				MCU_UpdateVolumeSlider();
-				break;
-
-			default:
-				break;
-		}
-
-		ints &= ~BIT(mcu_int_id);
-	}
-}
-
-void MCU_Init(void)
-{
-	u32 clrpend, mask = 0;
-
-	shell_state = SHELL_OPEN;
-
-	/* set register mask and clear any pending registers */
-	MCU_WriteRegBuf(REG_INT_EN, (const u8*)&mask, sizeof(mask));
-	MCU_ReadRegBuf(REG_INT_MASK, (u8*)&clrpend, sizeof(clrpend));
-
-	MCU_ResetLED();
-
-	MCU_UpdateVolumeSlider();
-	MCU_UpdateShellState(MCU_ReadReg(REG_CONSOLE_STATE) & BIT(1));
 
 	GPIO_setBit(19, 9);
 }
+
+static void evReset(void) {
+	atomic_store(&pendingEvents, 0);
+}
+
+static u32 evTest(u32 mask, u32 clear) {
+	mcuEventUpdate();
+	return atomic_fetch_and(&pendingEvents, ~clear) & mask;
+}
+
+static const EventInterface evMCU = {
+	.reset = evReset,
+	.test = evTest
+};
+
+const EventInterface *getEventMCU(void) {
+	return &evMCU;
+}
+

arm11/source/hw/mcu.h

@@ -26,51 +26,48 @@
 #define MCU_INTERRUPT	(0x71)
 #define I2C_MCU_DEVICE	(3)
 
-u8 MCU_GetVolumeSlider(void);
+enum {
-u32 MCU_GetSpecialHID(void);
+	MCUEV_HID_PWR_DOWN = BIT(0),
+	MCUEV_HID_PWR_HOLD = BIT(1),
+	MCUEV_HID_HOME_DOWN = BIT(2),
+	MCUEV_HID_HOME_UP = BIT(3),
+	MCUEV_HID_WIFI_SWITCH = BIT(4),
+	MCUEV_HID_SHELL_CLOSE = BIT(5),
+	MCUEV_HID_SHELL_OPEN = BIT(6),
+	MCUEV_HID_VOLUME_SLIDER = BIT(22),
+};
 
-void MCU_SetNotificationLED(u32 period_ms, u32 color);
+u8 mcuGetVolumeSlider(void);
-void MCU_ResetLED(void);
+u32 mcuGetSpecialHID(void);
 
-void MCU_HandleInterrupts(u32 irqn);
+void mcuSetStatusLED(u32 period_ms, u32 color);
+void mcuResetLEDs(void);
 
-void MCU_Init(void);
+void mcuReset(void);
 
-static inline u8 MCU_ReadReg(u8 addr)
+static inline u8 mcuReadReg(u8 addr)
 {
 	u8 val;
 	I2C_readRegBuf(I2C_MCU_DEVICE, addr, &val, 1);
 	return val;
 }
 
-static inline bool MCU_ReadRegBuf(u8 addr, u8 *buf, u32 size)
+static inline bool mcuReadRegBuf(u8 addr, u8 *buf, u32 size)
 {
 	return I2C_readRegBuf(I2C_MCU_DEVICE, addr, buf, size);
 }
 
-static inline bool MCU_WriteReg(u8 addr, u8 val)
+static inline bool mcuWriteReg(u8 addr, u8 val)
 {
 	return I2C_writeRegBuf(I2C_MCU_DEVICE, addr, &val, 1);
 }
 
-static inline bool MCU_WriteRegBuf(u8 addr, const u8 *buf, u32 size)
+static inline bool mcuWriteRegBuf(u8 addr, const u8 *buf, u32 size)
 {
 	return I2C_writeRegBuf(I2C_MCU_DEVICE, addr, buf, size);
 }
 
-static inline u32 MCU_waitEvents(u32 mask) {
-	u32 v;
-	while(1) {
-		TIMER_WaitMS(10);
-		MCU_ReadRegBuf(0x10, (u8*)&v, 4);
-		v &= mask;
-		if (v)
-			break;
-	}
-	return v;
-}
-
 static inline void MCU_controlLCDPower(u8 bits)
 {
-	MCU_WriteReg(0x22u, bits);
+	mcuWriteReg(0x22u, bits);
 }

arm11/source/main.c

@@ -31,6 +31,7 @@
 #include "hw/nvram.h"
 
 #include "system/sys.h"
+#include "system/event.h"
 
 static const u8 brLvlTbl[] = {
 	0x10, 0x17, 0x1E, 0x25,
@@ -44,12 +45,15 @@ static int oldBrLvl;
 static bool autoBr;
 #endif
 
-static SystemSHMEM __attribute__((section(".shared"))) SharedMemoryState;
+static SystemSHMEM __attribute__((section(".shared"))) sharedMem;
 
-void VBlank_Handler(u32 __attribute__((unused)) irqn)
+static void vblankUpdate(void)
 {
+	if (!getEventIRQ()->test(VBLANK_INTERRUPT, true))
+		return;
+
 	#ifndef FIXED_BRIGHTNESS
-	int newBrLvl = (MCU_GetVolumeSlider() >> 2) % countof(brLvlTbl);
+	int newBrLvl = (mcuGetVolumeSlider() >> 2) % countof(brLvlTbl);
 	if ((newBrLvl != oldBrLvl) && autoBr) {
 		oldBrLvl = newBrLvl;
 		u8 br = brLvlTbl[newBrLvl];
@@ -57,97 +61,135 @@ void VBlank_Handler(u32 __attribute__((unused)) irqn)
 	}
 	#endif
 
-	SharedMemoryState.hidState.full = HID_GetState();
+	// handle shell events
+	static const u32 mcuEvShell = MCUEV_HID_SHELL_OPEN | MCUEV_HID_SHELL_CLOSE;
+	u32 shell = getEventMCU()->test(mcuEvShell, mcuEvShell);
+	if (shell & MCUEV_HID_SHELL_CLOSE) {
+		GFX_powerOffBacklights(GFX_BLIGHT_BOTH);
+	} else if (shell & MCUEV_HID_SHELL_OPEN) {
+		GFX_powerOnBacklights(GFX_BLIGHT_BOTH);
+	}
+
+	sharedMem.hidState.full = HID_GetState();
 }
 
-static bool legacy_boot = false;
+static u32 pxiRxUpdate(u32 *args)
-
-void PXI_RX_Handler(u32 __attribute__((unused)) irqn)
 {
-	u32 ret, msg, cmd, argc, args[PXI_MAX_ARGS];
+	u32 msg, lo, hi;
+
+	if (!getEventIRQ()->test(PXI_RX_INTERRUPT, true))
+		return PXICMD_NONE;
 
 	msg = PXI_Recv();
-	cmd = msg & 0xFFFF;
+	lo = msg & 0xFFFF;
-	argc = msg >> 16;
+	hi = msg >> 16;
 
-	if (argc >= PXI_MAX_ARGS) {
+	PXI_RecvArray(args, hi);
-		PXI_Send(0xFFFFFFFF);
+	return lo;
-		return;
+}
-	}
 
-	PXI_RecvArray(args, argc);
+void __attribute__((noreturn)) MainLoop(void)
+{
+	bool runPxiCmdProcessor = true;
 
-	switch (cmd) {
+	#ifdef FIXED_BRIGHTNESS
-		case PXI_LEGACY_MODE:
+	u8 fixBrLvl = brLvlTbl[clamp(FIXED_BRIGHTNESS, 0, countof(brLvlTbl)-1)];
-		{
+	GFX_setBrightness(fixBrLvl, fixBrLvl);
-			// TODO: If SMP is enabled, an IPI should be sent here (with a DSB)
+	#else
-			legacy_boot = true;
+	oldBrLvl = -1;
-			ret = 0;
+	autoBr = true;
+	#endif
+
+	// initialize state stuff
+	getEventIRQ()->reset();
+	getEventMCU()->reset();
+	memset(&sharedMem, 0, sizeof(sharedMem));
+
+	// configure interrupts
+	gicSetInterruptConfig(PXI_RX_INTERRUPT, BIT(0), GIC_PRIO0, NULL);
+	gicSetInterruptConfig(VBLANK_INTERRUPT, BIT(0), GIC_PRIO0, NULL);
+	gicSetInterruptConfig(MCU_INTERRUPT, BIT(0), GIC_PRIO0, NULL);
+
+	// enable interrupts
+	gicEnableInterrupt(MCU_INTERRUPT);
+
+	// perform gpu init after initializing mcu but before
+	// enabling the pxi system and the vblank handler
+	GFX_init(GFX_RGB565);
+
+	gicEnableInterrupt(PXI_RX_INTERRUPT);
+	gicEnableInterrupt(VBLANK_INTERRUPT);
+
+	// ARM9 won't try anything funny until this point
+	PXI_Barrier(PXI_BOOT_BARRIER);
+
+	// Process commands until the ARM9 tells
+	// us it's time to boot something else
+	// also handles VBlank events as needed
+	do {
+		u32 pxiCmd, pxiReply, args[PXI_MAX_ARGS];
+
+		vblankUpdate();
+		pxiCmd = pxiRxUpdate(args);
+
+		switch(pxiCmd) {
+			// ignore args and just wait until the next event
+			case PXICMD_NONE:
+				ARM_WFI();
 				break;
-		}
 
-		case PXI_GET_SHMEM:
+			// revert to legacy boot mode
-		{
+			case PXICMD_LEGACY_BOOT:
-			ret = (u32)&SharedMemoryState;
+				runPxiCmdProcessor = false;
+				pxiReply = 0;
 				break;
-		}
 
-		case PXI_SET_VMODE:
+			// returns the shared memory address
-		{
+			case PXICMD_GET_SHMEM_ADDRESS:
-			GFX_init(args[0] ? GFX_BGR8 : GFX_RGB565);
+				pxiReply = (u32)&sharedMem;
-			ret = 0;
 				break;
-		}
 
-		case PXI_I2C_READ:
+			// takes in a single argument word and performs either an
+			// I2C read or write depending on the value of the top bit
+			case PXICMD_I2C_OP:
 			{
 				u32 devId, regAddr, size;
 
 				devId = (args[0] & 0xff);
-			regAddr = (args[0] >> 8) & 0xff;
+				regAddr = (args[0] >> 8) & 0xFF;
-			size = (args[0] >> 16) % I2C_SHARED_BUFSZ;
+				size = (args[0] >> 16) % SHMEM_BUFFER_SIZE;
 
-			ret = I2C_readRegBuf(devId, regAddr, SharedMemoryState.i2cBuffer, size);
+				if (args[0] & BIT(31)) {
+					pxiReply = I2C_writeRegBuf(devId, regAddr, sharedMem.dataBuffer.b, size);
+				} else {
+					pxiReply = I2C_readRegBuf(devId, regAddr, sharedMem.dataBuffer.b, size);
+				}
 				break;
 			}
 
-		case PXI_I2C_WRITE:
+			// checks whether the NVRAM chip is online (not doing any work)
-		{
+			case PXICMD_NVRAM_ONLINE:
-			u32 devId, regAddr, size;
+				pxiReply = (NVRAM_Status() & NVRAM_SR_WIP) == 0;
-
-			devId = (args[0] & 0xff);
-			regAddr = (args[0] >> 8) & 0xff;
-			size = (args[0] >> 16) % I2C_SHARED_BUFSZ;
-
-			ret = I2C_writeRegBuf(devId, regAddr, SharedMemoryState.i2cBuffer, size);
 				break;
-		}
 
-		case PXI_NVRAM_ONLINE:
+			// reads data from the NVRAM chip
-		{
+			case PXICMD_NVRAM_READ:
-			ret = (NVRAM_Status() & NVRAM_SR_WIP) == 0;
+				NVRAM_Read(args[0], sharedMem.dataBuffer.w, args[1]);
+				pxiReply = 0;
 				break;
-		}
 
-		case PXI_NVRAM_READ:
+			// sets the notification LED with the given color and period
-		{
+			case PXICMD_SET_NOTIFY_LED:
-			NVRAM_Read(args[0], (u32*)SharedMemoryState.spiBuffer, args[1]);
+				mcuSetStatusLED(args[0], args[1]);
-			ret = 0;
+				pxiReply = 0;
 				break;
-		}
 
-		case PXI_NOTIFY_LED:
+			// sets the LCDs brightness (if FIXED_BRIGHTNESS is disabled)
+			case PXICMD_SET_BRIGHTNESS:
 			{
-			MCU_SetNotificationLED(args[0], args[1]);
-			ret = 0;
-			break;
-		}
-
-		case PXI_BRIGHTNESS:
-		{
-			ret = GFX_getBrightness();
-			#ifndef FIXED_BRIGHTNESS
 				s32 newbrightness = (s32)args[0];
+				pxiReply = GFX_getBrightness();
+				#ifndef FIXED_BRIGHTNESS
 				if ((newbrightness > 0) && (newbrightness < 0x100)) {
 					GFX_setBrightness(newbrightness, newbrightness);
 					autoBr = false;
@@ -159,51 +201,25 @@ void PXI_RX_Handler(u32 __attribute__((unused)) irqn)
 				break;
 			}
 
-		/* New CMD template:
+			// replies -1 on default
-		case CMD_ID:
-		{
-			<var declarations/assignments>
-			<execute the command>
-			<set the return value>
-			break;
-		}
-		*/
-
 			default:
-			ret = 0xFFFFFFFF;
+				pxiReply = 0xFFFFFFFF;
 				break;
 		}
 
-	PXI_Send(ret);
+		if (pxiCmd != PXICMD_NONE)
-}
+			PXI_Send(pxiReply); // was a command sent from the ARM9, send a response
+	} while(runPxiCmdProcessor);
 
-void __attribute__((noreturn)) MainLoop(void)
+	// perform deinit in reverse order
-{
+	gicDisableInterrupt(VBLANK_INTERRUPT);
-	#ifdef FIXED_BRIGHTNESS
+	gicDisableInterrupt(PXI_RX_INTERRUPT);
-	u8 fixBrLvl = brLvlTbl[clamp(FIXED_BRIGHTNESS, 0, countof(brLvlTbl)-1)];
-	GFX_setBrightness(fixBrLvl, fixBrLvl);
-	#else
-	oldBrLvl = -1;
-	autoBr = true;
-	#endif
 
-	// configure interrupts
+	// unconditionally reinitialize the screens
-	gicSetInterruptConfig(PXI_RX_INTERRUPT, BIT(0), GIC_PRIO2, PXI_RX_Handler);
+	// in RGB24 framebuffer mode
-	gicSetInterruptConfig(MCU_INTERRUPT, BIT(0), GIC_PRIO1, MCU_HandleInterrupts);
+	GFX_init(GFX_BGR8);
-	gicSetInterruptConfig(VBLANK_INTERRUPT, BIT(0), GIC_PRIO0, VBlank_Handler);
 
-	// enable interrupts
+	gicDisableInterrupt(MCU_INTERRUPT);
-	gicEnableInterrupt(PXI_RX_INTERRUPT);
-	gicEnableInterrupt(MCU_INTERRUPT);
-	gicEnableInterrupt(VBLANK_INTERRUPT);
-
-	// ARM9 won't try anything funny until this point
-	PXI_Barrier(PXI_BOOT_BARRIER);
-
-	// Process IRQs until the ARM9 tells us it's time to boot something else
-	do {
-		ARM_WFI();
-	} while(!legacy_boot);
 
 	// Wait for the ARM9 to do its firmlaunch setup
 	PXI_Barrier(PXI_FIRMLAUNCH_BARRIER);

arm11/source/system/event.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <types.h>
+
+typedef struct {
+	void (*reset)(void);
+	u32 (*test)(u32 param, u32 clear);
+} EventInterface;
+
+const EventInterface *getEventIRQ(void);
+const EventInterface *getEventMCU(void);
+
+static inline void eventReset(const EventInterface *ei) {
+	ei->reset();
+}
+
+static inline u32 eventTest(const EventInterface *ei, u32 param, u32 clear) {
+	return ei->test(param, clear);
+}
+
+static inline u32 eventWait(const EventInterface *ei, u32 param, u32 clear) {
+	while(1) {
+		u32 ret = ei->test(param, clear);
+		if (ret) return ret;
+	}
+}

arm11/source/system/sys.c

@@ -107,20 +107,17 @@ void SYS_CoreZeroInit(void)
 		mmuMapArea(0x20000000, 0x20000000, 128UL << 20, MMU_FLAGS(MMU_CACHE_WB, MMU_READ_WRITE, 1, 1));
 	}
 
-	if (SYS_IsNewConsole()) {
+	// screen init magicks
-		TIMER_WaitMS(150);
+	TIMER_WaitMS(64);
-	}
 
 	// Initialize peripherals
 	PXI_Reset();
 
 	I2C_init();
-	MCU_Init();
+	mcuReset();
 
 	SPI_Init();
 	CODEC_Init();
-
-	GFX_init(GFX_RGB565);
 }
 
 void SYS_CoreInit(void)

arm9/source/common/hid.c

@@ -19,7 +19,7 @@ static void SetNotificationLED(u32 period_ms, u32 rgb565_color)
         (rgb565_color >> 5) << (8+2) |
         (rgb565_color << 3));
     u32 args[] = {period_ms, rgb888_color};
-    PXI_DoCMD(PXI_NOTIFY_LED, args, 2);
+    PXI_DoCMD(PXICMD_SET_NOTIFY_LED, args, 2);
 }
 
 // there's some weird thing going on when reading this

arm9/source/common/power.c

@@ -12,7 +12,7 @@ u32 SetScreenBrightness(int level) {
         arg = 0;
     }
 
-    return PXI_DoCMD(PXI_BRIGHTNESS, &arg, 1);
+    return PXI_DoCMD(PXICMD_SET_BRIGHTNESS, &arg, 1);
 }
 
 u32 GetBatteryPercent() {

arm9/source/godmode.c

@@ -108,8 +108,7 @@ u32 BootFirmHandler(const char* bootpath, bool verbose, bool delete) {
         if (delete) PathDelete(bootpath);
         DeinitExtFS();
         DeinitSDCardFS();
-        PXI_DoCMD(PXI_SET_VMODE, (u32[]){1}, 1);
+        PXI_DoCMD(PXICMD_LEGACY_BOOT, NULL, 0);
-        PXI_DoCMD(PXI_LEGACY_MODE, NULL, 0);
         PXI_Barrier(PXI_FIRMLAUNCH_BARRIER);
         BootFirm((FirmHeader*) firm, fixpath);
         while(1);

arm9/source/main.c

@@ -7,7 +7,7 @@
 
 #include "hid.h"
 
-SystemSHMEM *shmemGlobalBase;
+SystemSHMEM *shmemBasePtr;
 
 void main(int argc, char** argv, int entrypoint)
 {

arm9/source/system/i2c.c

@@ -8,32 +8,33 @@
 bool I2C_readRegBuf(I2cDevice devId, u8 regAddr, u8 *out, u32 size)
 {
 	int ret;
+	u8 *const dataBuffer = ARM_GetSHMEM()->dataBuffer.b;
 	const u32 arg = devId | (regAddr << 8) | (size << 16);
 
-	if (size >= I2C_SHARED_BUFSZ)
+	if (size >= SHMEM_BUFFER_SIZE)
 		return false;
 
-	ret = PXI_DoCMD(PXI_I2C_READ, &arg, 1);
+	ret = PXI_DoCMD(PXICMD_I2C_OP, &arg, 1);
+	ARM_InvDC_Range(dataBuffer, size);
 
-	ARM_InvDC_Range(ARM_GetSHMEM()->i2cBuffer, size);
+	memcpy(out, dataBuffer, size);
-	memcpy(out, ARM_GetSHMEM()->i2cBuffer, size);
 	return ret;
 }
 
 bool I2C_writeRegBuf(I2cDevice devId, u8 regAddr, const u8 *in, u32 size)
 {
 	int ret;
-	const u32 arg = devId | (regAddr << 8) | (size << 16);
+	u8 *const dataBuffer = ARM_GetSHMEM()->dataBuffer.b;
+	const u32 arg = devId | (regAddr << 8) | (size << 16) | BIT(31);
 
-	if (size >= I2C_SHARED_BUFSZ)
+	if (size >= SHMEM_BUFFER_SIZE)
 		return false;
 
-	ARM_InvDC_Range(ARM_GetSHMEM()->i2cBuffer, size);
+	memcpy(dataBuffer, in, size);
-	memcpy(ARM_GetSHMEM()->i2cBuffer, in, size);
+	ARM_WbDC_Range(dataBuffer, size);
-	ARM_WbDC_Range(ARM_GetSHMEM()->i2cBuffer, size);
 	ARM_DSB();
 
-	ret = PXI_DoCMD(PXI_I2C_WRITE, &arg, 1);
+	ret = PXI_DoCMD(PXICMD_I2C_OP, &arg, 1);
 	return ret;
 }
 

arm9/source/system/spiflash.c

@@ -5,24 +5,25 @@
 
 bool spiflash_get_status(void)
 {
-	return PXI_DoCMD(PXI_NVRAM_ONLINE, NULL, 0);
+	return PXI_DoCMD(PXICMD_NVRAM_ONLINE, NULL, 0);
 }
 
 bool spiflash_read(u32 offset, u32 size, u8 *buf)
 {
+	u32 *const dataBuffer = ARM_GetSHMEM()->dataBuffer.w;
 	u32 args[2];
 
 	while(size > 0) {
-		u32 blksz = min(size, SPI_SHARED_BUFSZ);
+		u32 blksz = min(size, SHMEM_BUFFER_SIZE);
 
 		args[0] = offset;
 		args[1] = blksz;
 
-		ARM_WbDC_Range(ARM_GetSHMEM()->spiBuffer, blksz);
+		PXI_DoCMD(PXICMD_NVRAM_READ, args, 2);
-		PXI_DoCMD(PXI_NVRAM_READ, args, 2);
+		ARM_InvDC_Range(dataBuffer, blksz);
-		ARM_InvDC_Range(ARM_GetSHMEM()->spiBuffer, blksz);
 		ARM_DSB();
-		memcpy(buf, ARM_GetSHMEM()->spiBuffer, blksz);
+
+		memcpy(buf, dataBuffer, blksz);
 
 		buf += blksz;
 		size -= blksz;

arm9/source/utils/scripting.c

@@ -1426,8 +1426,7 @@ bool run_cmd(cmd_id id, u32 flags, char** argv, char* err_str) {
                 fixpath[255] = '\0';
                 DeinitExtFS();
                 DeinitSDCardFS();
-                PXI_DoCMD(PXI_SET_VMODE, (u32[]){1}, 1);
+                PXI_DoCMD(PXICMD_LEGACY_BOOT, NULL, 0);
-                PXI_DoCMD(PXI_LEGACY_MODE, NULL, 0);
                 PXI_Barrier(PXI_FIRMLAUNCH_BARRIER);
                 BootFirm((FirmHeader*)(void*)firm, fixpath);
                 while(1);

common/common.h

@@ -53,7 +53,7 @@
     (sizeof(x) / sizeof(*(x)))
 
 #define bkpt \
-    __builtin_trap()
+    do{__builtin_trap(); __builtin_unreachable();}while(0)
 
 #define assert(x) \
     (!!(x) ? (void)0 : __builtin_trap())

common/pxi.h

@@ -28,18 +28,17 @@
 #endif
 
 enum {
-	PXI_LEGACY_MODE = 0,
+	PXICMD_LEGACY_BOOT = 0,
-	PXI_GET_SHMEM,
+	PXICMD_GET_SHMEM_ADDRESS,
-	PXI_SET_VMODE,
 
-	PXI_I2C_READ,
+	PXICMD_I2C_OP,
-	PXI_I2C_WRITE,
+	PXICMD_NVRAM_ONLINE,
+	PXICMD_NVRAM_READ,
 
-	PXI_NVRAM_ONLINE,
+	PXICMD_SET_NOTIFY_LED,
-	PXI_NVRAM_READ,
+	PXICMD_SET_BRIGHTNESS,
 
-	PXI_NOTIFY_LED,
+	PXICMD_NONE,
-	PXI_BRIGHTNESS
 };
 
 /*

common/shmem.h

@@ -20,8 +20,7 @@
 
 #include <arm.h>
 
-#define I2C_SHARED_BUFSZ 1024
+#define SHMEM_BUFFER_SIZE 2048
-#define SPI_SHARED_BUFSZ 1024
 
 typedef struct {
 	union {
@@ -29,14 +28,18 @@ typedef struct {
 		u64 full;
 	} hidState;
 
-	u8 i2cBuffer[I2C_SHARED_BUFSZ];
+	union {
-	u32 spiBuffer[SPI_SHARED_BUFSZ/4];
+		uint8_t b[SHMEM_BUFFER_SIZE];
+		uint16_t s[SHMEM_BUFFER_SIZE / 2];
+		uint32_t w[SHMEM_BUFFER_SIZE / 4];
+		uint64_t q[SHMEM_BUFFER_SIZE / 8];
+	} dataBuffer;
 } __attribute__((packed, aligned(8))) SystemSHMEM;
 
 #ifdef ARM9
 #include <pxi.h>
 
-extern SystemSHMEM *shmemGlobalBase;
+extern SystemSHMEM *shmemBasePtr;
 
 static inline SystemSHMEM *ARM_GetSHMEM(void)
 {
@@ -44,11 +47,11 @@ static inline SystemSHMEM *ARM_GetSHMEM(void)
 	// insert a compiler barrier to force the compiler not to assume
 	// memory values will remain constant in between calls to getSHMEM
 	asm_v("":::"memory", "cc");
-	return shmemGlobalBase;
+	return shmemBasePtr;
 }
 
 static inline void ARM_InitSHMEM(void)
 {
-	shmemGlobalBase = (SystemSHMEM*)PXI_DoCMD(PXI_GET_SHMEM, NULL, 0);
+	shmemBasePtr = (SystemSHMEM*)PXI_DoCMD(PXICMD_GET_SHMEM_ADDRESS, NULL, 0);
 }
 #endif