Added bootloader.

1 files changed, 305 insertions, 0 deletions

diff --git a/bootloader.cpp b/bootloader.cpp
new file mode 100644
index 0000000..fa79d9b
--- /dev/null
+++ b/bootloader.cpp
@@ -0,0 +1,305 @@
+#include <rcc/rcc.h>
+#include <rcc/flash.h>
+#include <gpio/gpio.h>
+#include <interrupt/interrupt.h>
+#include <os/time.h>
+#include <usb/usb.h>
+#include <usb/descriptor.h>
+#include <usb/hid.h>
+#include <usb/dfu.h>
+
+void reset() {
+	SCB.AIRCR = (0x5fa << 16) | (1 << 2); // SYSRESETREQ
+}
+
+auto dev_desc = device_desc(0x200, 0, 0, 0, 64, 0x1d50, 0x6084, 0, 0, 0, 0, 1);
+auto conf_desc = configuration_desc(1, 1, 0, 0xc0, 0,
+	interface_desc(0, 0, 0, 0xfe, 0x01, 0x02, 0,
+		dfu_functional_desc(0x0d, 0, 64, 0x110)
+	)
+	// HID interface.
+	//interface_desc(1, 0, 1, 0x03, 0x00, 0x00, 0,
+	//	hid_desc(0x111, 0, 1, 0x22, sizeof(report_desc)),
+	//	endpoint_desc(0x81, 0x03, 16, 1)
+	//)
+);
+
+desc_t dev_desc_p = {sizeof(dev_desc), (void*)&dev_desc};
+desc_t conf_desc_p = {sizeof(conf_desc), (void*)&conf_desc};
+//desc_t report_desc_p = {sizeof(report_desc), (void*)&report_desc};
+
+static Pin usb_dm = GPIOA[11];
+static Pin usb_dp = GPIOA[12];
+static Pin usb_pu = GPIOA[15];
+
+static PinArray button_inputs = GPIOB.array(0, 10);
+static PinArray button_leds = GPIOC.array(0, 10);
+
+static Pin led1 = GPIOB[14];
+
+USB_f1 usb(USB, dev_desc_p, conf_desc_p);
+
+class Flashloader {
+	private:
+		bool state;
+		uint32_t addr;
+	
+	public:
+		Flashloader() : state(false) {}
+		
+		bool prepare() {
+			addr = 0x8002000;
+			state = true;
+			
+			// Unlock flash.
+			FLASH.KEYR = 0x45670123;
+			FLASH.KEYR = 0xCDEF89AB;
+			
+			return true;
+		}
+		
+		bool write_block(uint32_t size, void* data) {
+			if(!state) {
+				return false;
+			}
+			
+			if(size & 1) {
+				return false;
+			}
+			
+			if(addr + size > 0x8020000) {
+				return false;
+			}
+			
+			if(!(addr & (2048 - 1))) {
+				// Erase page.
+				
+				FLASH.CR = 1 << 1; // PER
+				FLASH.AR = addr;
+				FLASH.CR = (1 << 6) | (1 << 1); // STRT, PER
+				
+				while(FLASH.SR & (1 << 0)); // BSY
+				
+				FLASH.SR &= ~(1 << 5); // EOP
+				FLASH.CR = 0;
+			}
+			
+			uint16_t* src = (uint16_t*)data;
+			uint16_t* dest = (uint16_t*)addr;
+			
+			for(uint32_t n = 0; n < size; n += 2) {
+				FLASH.CR = 1 << 0; // PG
+				
+				*dest++ = *src++;
+				
+				while(FLASH.SR & (1 << 0)); // BSY
+			}
+			
+			
+			addr += size;
+			return true;
+		}
+		
+		bool finish() {
+			state = false;
+			
+			FLASH.CR = 1 << 7; // LOCK
+			
+			return true;
+		}
+};
+
+Flashloader flashloader;
+
+class USB_DFU : public USB_class_driver {
+	private:
+		USB_generic& usb;
+		
+		uint8_t state;
+		
+		bool get_status(uint16_t wValue, uint16_t wIndex, uint16_t wLength) {
+			if(wLength > 6) {
+				wLength = 6;
+			}
+			
+			uint8_t buf[] = {0, 0, 0, 0, state, 0};
+			
+			usb.write(0, (uint32_t*)buf, wLength);
+			
+			return true;
+		}
+		
+		bool download(uint16_t wValue, uint16_t wIndex, uint16_t wLength) {
+			if(!wLength) {
+				state = 2;
+				
+				if(!flashloader.finish()) {
+					return false;
+				}
+				
+				usb.write(0, nullptr, 0);
+				
+				return true;
+			}
+			
+			if(state == 2) {
+				state = 5;
+				
+				return flashloader.prepare();
+			}
+			
+			return true;
+		}
+		
+	public:
+		USB_DFU(USB_generic& usbd) : usb(usbd), state(2) {
+			usb.register_driver(this);
+		}
+	
+	protected:
+		virtual SetupStatus handle_setup(uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex, uint16_t wLength) {
+			// DFU_GETSTATUS
+			if(bmRequestType == 0xa1 && bRequest == 0x03) {
+				return get_status(wValue, wIndex, wLength) ? SetupStatus::Ok : SetupStatus::Stall;
+			}
+			
+			// DFU_CLRSTATUS
+			// DFU_GETSTATE
+			// DFU_ABORT
+			
+			// DFU_DNLOAD
+			if(bmRequestType == 0x21 && bRequest == 0x01) {
+				return download(wValue, wIndex, wLength) ? SetupStatus::Ok : SetupStatus::Stall;
+			}
+			
+			return SetupStatus::Unhandled;
+		}
+		
+		virtual void handle_out(uint8_t ep, uint32_t len) {
+			if(ep != 0 || len == 0) {
+				return;
+			}
+			
+			uint32_t buf[16];
+			usb.read(ep, buf, len);
+			
+			if(state == 5) {
+				flashloader.write_block(len, buf);
+			}
+			
+			usb.write(0, nullptr, 0);
+		}
+};
+
+USB_DFU usb_dfu(usb);
+
+/*
+uint32_t last_led_time;
+
+class HID_arcin : public USB_HID {
+	public:
+		HID_arcin(USB_generic& usbd, desc_t rdesc) : USB_HID(usbd, rdesc, 1, 1, 64) {}
+	
+	protected:
+		virtual bool set_output_report(uint32_t* buf, uint32_t len) {
+			last_led_time = Time::time();
+			button_leds.set(*buf);
+			return true;
+		}
+};
+
+HID_arcin usb_hid(usb, report_desc_p);
+*/
+
+void chainload(uint32_t offset) {
+	SCB.VTOR = offset;
+	
+	asm volatile("ldr sp, [%0]; ldr %0, [%0, #4]; bx %0" :: "r" (offset));
+}
+
+uint32_t& reset_reason = *(uint32_t*)0x10000000;
+uint32_t* firmware_vtors = (uint32_t*)0x8002000;
+
+bool normal_boot() {
+	// Check if this was a reset-to-bootloader.
+	if(reset_reason == 0xb007) {
+		reset_reason = 0;
+		return false;
+	}
+	
+	// Check buttons.
+	if((button_inputs.get() ^ 0x7ff) == ((1 << 1) | (1 << 0))) {
+		return false;
+	}
+	
+	// Check that reset vector is a valid flash address.
+	uint32_t reset_vector = firmware_vtors[1];
+	if(reset_vector < 0x8002000 || reset_vector >= 0x8020000) {
+		return false;
+	}
+	
+	// No reason to enter bootloader.
+	return true;
+}
+
+int main() {
+	RCC.enable(RCC.GPIOA);
+	RCC.enable(RCC.GPIOB);
+	RCC.enable(RCC.GPIOC);
+	
+	button_inputs.set_mode(Pin::Input);
+	button_inputs.set_pull(Pin::PullUp);
+	
+	button_leds.set_mode(Pin::Output);
+	
+	led1.set_mode(Pin::Output);
+	
+	if(normal_boot()) {
+		chainload(0x8002000);
+	}
+	
+	rcc_init();
+	
+	// Initialize system timer.
+	STK.LOAD = 72000000 / 8 / 1000; // 1000 Hz.
+	STK.CTRL = 0x03;
+	
+	usb_dm.set_mode(Pin::AF);
+	usb_dm.set_af(14);
+	usb_dp.set_mode(Pin::AF);
+	usb_dp.set_af(14);
+	
+	RCC.enable(RCC.USB);
+	
+	usb.init();
+	
+	usb_pu.set_mode(Pin::Output);
+	usb_pu.on();
+	
+	
+	while(1) {
+		usb.process();
+		
+		if(~button_inputs.get() & (1 << 5)) {
+			reset();
+		}
+		
+		GPIOC[0].set(Time::time() & 512);
+		
+		/*
+		usb.process();
+		
+		uint16_t buttons = button_inputs.get() ^ 0x7ff;
+		
+		if(Time::time() - last_led_time > 1000) {
+			button_leds.set(buttons);
+		}
+		
+		if(usb.ep_ready(1)) {
+			report_t report = {buttons, uint8_t(TIM2.CNT), uint8_t(TIM3.CNT)};
+			
+			usb.write(1, (uint32_t*)&report, sizeof(report));
+		}
+		*/
+	}
+}