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-rw-r--r--bootloader.cpp306
1 files changed, 306 insertions, 0 deletions
diff --git a/bootloader.cpp b/bootloader.cpp
new file mode 100644
index 0000000..a2cf77c
--- /dev/null
+++ b/bootloader.cpp
@@ -0,0 +1,306 @@
+#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>
+
+Pin button = GPIOA[3];
+Pin led = GPIOA[4];
+
+static uint32_t& reset_reason = *(uint32_t*)0x10000000;
+static const uint32_t* firmware_vtors = (uint32_t*)0x8002000;
+
+static bool do_reset;
+
+void reset() {
+ SCB.AIRCR = (0x5fa << 16) | (1 << 2); // SYSRESETREQ
+}
+
+void chainload(uint32_t offset) {
+ SCB.VTOR = offset;
+
+ asm volatile("ldr r1, [%0]; mov sp, r1; ldr %0, [%0, #4]; bx %0" :: "r" (offset) : "r1");
+
+ while(1);
+}
+
+auto report_desc = pack(
+ usage_page(0xff55),
+ usage(0xb007),
+ collection(Collection::Application,
+ logical_minimum(0),
+ logical_maximum(255),
+ report_size(8),
+ report_count(1),
+
+ usage(0xb007),
+ input(0x02), // Status
+
+ usage(0xb007),
+ feature(0x02), // Function
+
+ usage(0xb007),
+ report_count(64),
+ output(0x02) // Data
+ )
+);
+
+auto dev_desc = device_desc(0x200, 0, 0, 0, 64, 0x1d50, 0x60f7, 0x100, 1, 2, 3, 1);
+auto conf_desc = configuration_desc(1, 1, 0, 0xc0, 0,
+ // HID interface.
+ interface_desc(0, 0, 1, 0x03, 0x00, 0x00, 0,
+ hid_desc(0x111, 0, 1, 0x22, sizeof(report_desc)),
+ endpoint_desc(0x81, 0x03, 64, 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};
+
+USB_l0 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.PEKEYR = 0x89ABCDEF;
+ FLASH.PEKEYR = 0x02030405;
+ FLASH.PRGKEYR = 0x8C9DAEBF;
+ FLASH.PRGKEYR = 0x13141516;
+
+ return true;
+ }
+
+ bool write_block(uint32_t size, void* data) {
+ if(!state) {
+ return false;
+ }
+
+ if(size & (4 - 1)) {
+ return false;
+ }
+
+ if(addr + size > 0x8010000) {
+ return false;
+ }
+
+ if(!(addr & (128 - 1))) {
+ // Erase page.
+
+ FLASH.PECR = (1 << 9) | (1 << 3); // ERASE, PROG
+ while(FLASH.SR & (1 << 0)); // BSY
+
+ *(uint32_t*)addr = 0;
+ }
+
+ uint32_t* src = (uint32_t*)data;
+ uint32_t* dest = (uint32_t*)addr;
+
+ for(uint32_t n = 0; n < size; n += 4) {
+ FLASH.PECR = 0;
+ while(FLASH.SR & (1 << 0)); // BSY
+
+ *dest++ = *src++;
+ }
+
+ addr += size;
+ return true;
+ }
+
+ bool finish() {
+ state = false;
+
+ FLASH.PECR = (1 << 1) | (1 << 0); // PRGLOCK, PELOCK
+
+ return true;
+ }
+};
+
+Flashloader flashloader;
+
+class HID_bootloader : public USB_HID {
+ public:
+ HID_bootloader(USB_generic& usbd, desc_t rdesc) : USB_HID(usbd, rdesc, 0, 1, 64) {}
+
+ protected:
+ virtual bool set_output_report(uint32_t* buf, uint32_t len) {
+ if(len != 64) {
+ return false;
+ }
+
+ return flashloader.write_block(len, buf);
+ }
+
+ virtual bool set_feature_report(uint32_t* buf, uint32_t len) {
+ if(len != 1) {
+ return false;
+ }
+
+ switch(*buf & 0xff) {
+ case 0:
+ return true;
+
+ case 0x10: // Reset to bootloader
+ return false; // Not available in bootloader mode
+
+ case 0x11: // Reset to runtime
+ do_reset = true;
+ return true;
+
+ case 0x20: // Flash prepare
+ return flashloader.prepare();
+
+ case 0x21: // Flash finish
+ return flashloader.finish();
+
+ default:
+ return false;
+ }
+ }
+};
+
+HID_bootloader usb_hid(usb, report_desc_p);
+
+uint32_t serial_num() {
+ uint32_t* uid = (uint32_t*)0x1ff80050;
+
+ return uid[0] * uid[1] * uid[5];
+}
+
+class USB_strings : public USB_class_driver {
+ private:
+ USB_generic& usb;
+
+ public:
+ USB_strings(USB_generic& usbd) : usb(usbd) {
+ usb.register_driver(this);
+ }
+
+ protected:
+ virtual SetupStatus handle_setup(uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex, uint16_t wLength) {
+ // Get string descriptor.
+ if(bmRequestType == 0x80 && bRequest == 0x06 && (wValue & 0xff00) == 0x0300) {
+ const void* desc = nullptr;
+ uint16_t buf[9];
+
+ switch(wValue & 0xff) {
+ case 0:
+ desc = u"\u0304\u0409";
+ break;
+
+ case 1:
+ desc = u"\u0308zyp";
+ break;
+
+ case 2:
+ desc = u"\u0322arcin bootloader";
+ break;
+
+ case 3:
+ {
+ buf[0] = 0x0312;
+ uint32_t id = serial_num();
+ for(int i = 8; i > 0; i--) {
+ buf[i] = (id & 0xf) > 9 ? 'A' + (id & 0xf) - 0xa : '0' + (id & 0xf);
+ id >>= 4;
+ }
+ desc = buf;
+ }
+ break;
+ }
+
+ if(!desc) {
+ return SetupStatus::Unhandled;
+ }
+
+ uint8_t len = *(uint8_t*)desc;
+
+ if(len > wLength) {
+ len = wLength;
+ }
+
+ usb.write(0, (uint32_t*)desc, len);
+
+ return SetupStatus::Ok;
+ }
+
+ return SetupStatus::Unhandled;
+ }
+};
+
+USB_strings usb_strings(usb);
+
+bool normal_boot() {
+ // Check if this was a reset-to-bootloader.
+ //if(reset_reason == 0xb007) {
+ // reset_reason = 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 >= 0x8010000) {
+ return false;
+ }
+
+ // Check buttons.
+ if(!button.get()) {
+ return false;
+ }
+
+ // No reason to enter bootloader.
+ return true;
+}
+
+int main() {
+ RCC.enable(RCC.GPIOA);
+ RCC.enable(RCC.GPIOB);
+ RCC.enable(RCC.GPIOC);
+
+ button.set_mode(Pin::Input);
+ button.set_pull(Pin::PullUp);
+
+ if(normal_boot()) {
+ chainload(0x8002000);
+ }
+
+ rcc_init();
+
+ // Initialize system timer.
+ STK.LOAD = 32000000 / 8 / 1000; // 1000 Hz.
+ STK.VAL = 0;
+ STK.CTRL = 0x03;
+
+ led.set_mode(Pin::Output);
+
+ RCC.enable(RCC.USB);
+
+ usb.init();
+
+ Time::sleep(10);
+ USB.reg.BCDR |= 1 << 15;
+
+ while(1) {
+ usb.process();
+
+ if(do_reset) {
+ Time::sleep(10);
+ reset();
+ }
+
+ led.set(Time::time() & 512);
+ }
+}