lib/dfu-bootloader.c

   1 /*
   2  *      Generic DFU Bootloader
   3  *
   4  *      (c) 2020 Martin Mareš <mj@ucw.cz>
   5  *
   6  *      Based on example code from the libopencm3 project, which is
   7  *      Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
   8  *
   9  *      Licensed under the GNU LGPL v3 or any later version.
  10  */
  11
  12 #include "util.h"
  13
  14 #include <libopencm3/cm3/cortex.h>
  15 #include <libopencm3/cm3/nvic.h>
  16 #include <libopencm3/cm3/scb.h>
  17 #include <libopencm3/cm3/systick.h>
  18 #include <libopencm3/stm32/rcc.h>
  19 #include <libopencm3/stm32/gpio.h>
  20 #include <libopencm3/stm32/flash.h>
  21 #include <libopencm3/stm32/usart.h>
  22 #include <libopencm3/stm32/desig.h>
  23 #include <libopencm3/usb/usbd.h>
  24 #include <libopencm3/usb/dfu.h>
  25
  26 #include <string.h>
  27
  28 #ifdef BOOTLOADER_DEBUG
  29 #define DEBUG(x...) debug_printf(x)
  30 #else
  31 #define DEBUG(x...) do { } while (0)
  32 #endif
  33
  34 byte usbd_control_buffer[1024];
  35
  36 static enum dfu_state usbdfu_state = STATE_DFU_IDLE;
  37
  38 static struct {
  39         byte buf[sizeof(usbd_control_buffer)];
  40         u16 len;
  41         u32 addr;
  42         u16 blocknum;
  43 } prog;
  44
  45 static char usb_serial_number[13];
  46
  47 enum usb_string {
  48         STR_MANUFACTURER = 1,
  49         STR_DEVICE,
  50         STR_SERIAL,
  51 };
  52
  53 static const char *usb_strings[] = {
  54         BOOTLOADER_MFG_NAME,
  55         BOOTLOADER_DEV_NAME,
  56         usb_serial_number,
  57 };
  58
  59 const struct usb_device_descriptor dev = {
  60         .bLength = USB_DT_DEVICE_SIZE,
  61         .bDescriptorType = USB_DT_DEVICE,
  62         .bcdUSB = 0x0200,
  63         .bDeviceClass = 0,
  64         .bDeviceSubClass = 0,
  65         .bDeviceProtocol = 0,
  66         .bMaxPacketSize0 = 64,
  67         .idVendor = BOOTLOADER_MFG_ID,
  68         .idProduct = BOOTLOADER_DEV_ID,
  69         .bcdDevice = BOOTLOADER_DEV_VERSION,
  70         .iManufacturer = STR_MANUFACTURER,
  71         .iProduct = STR_DEVICE,
  72         .iSerialNumber = STR_SERIAL,
  73         .bNumConfigurations = 1,
  74 };
  75
  76 const struct usb_dfu_descriptor dfu_function = {
  77         .bLength = sizeof(struct usb_dfu_descriptor),
  78         .bDescriptorType = DFU_FUNCTIONAL,
  79         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
  80         .wDetachTimeout = 255,
  81         .wTransferSize = 1024,
  82         .bcdDFUVersion = 0x0100,
  83 };
  84
  85 const struct usb_interface_descriptor iface = {
  86         .bLength = USB_DT_INTERFACE_SIZE,
  87         .bDescriptorType = USB_DT_INTERFACE,
  88         .bInterfaceNumber = 0,
  89         .bAlternateSetting = 0,
  90         .bNumEndpoints = 0,
  91         .bInterfaceClass = 0xFE, /* Device Firmware Upgrade */
  92         .bInterfaceSubClass = 1,
  93         .bInterfaceProtocol = 2,
  94         .extra = &dfu_function,
  95         .extralen = sizeof(dfu_function),
  96 };
  97
  98 const struct usb_interface ifaces[] = {{
  99         .num_altsetting = 1,
 100         .altsetting = &iface,
 101 }};
 102
 103 const struct usb_config_descriptor config = {
 104         .bLength = USB_DT_CONFIGURATION_SIZE,
 105         .bDescriptorType = USB_DT_CONFIGURATION,
 106         .wTotalLength = 0,
 107         .bNumInterfaces = 1,
 108         .bConfigurationValue = 1,
 109         .iConfiguration = 0,
 110         .bmAttributes = USB_CONFIG_ATTR_DEFAULT,        // bus-powered
 111         .bMaxPower = 50,                                // multiplied by 2 mA
 112         .interface = ifaces,
 113 };
 114
 115 static byte usbdfu_getstatus(usbd_device *usbd_dev UNUSED, u32 *bwPollTimeout)
 116 {
 117         switch (usbdfu_state) {
 118         case STATE_DFU_DNLOAD_SYNC:
 119                 usbdfu_state = STATE_DFU_DNBUSY;
 120                 *bwPollTimeout = 100;
 121                 return DFU_STATUS_OK;
 122         case STATE_DFU_MANIFEST_SYNC:
 123                 /* Device will reset when read is complete. */
 124                 usbdfu_state = STATE_DFU_MANIFEST;
 125                 return DFU_STATUS_OK;
 126         default:
 127                 return DFU_STATUS_OK;
 128         }
 129 }
 130
 131 static void usbdfu_getstatus_complete(usbd_device *usbd_dev UNUSED, struct usb_setup_data *req UNUSED)
 132 {
 133         switch (usbdfu_state) {
 134         case STATE_DFU_DNBUSY: {
 135                 flash_unlock();
 136                 u32 baseaddr = BOOTLOADER_APP_START + prog.blocknum * dfu_function.wTransferSize;
 137                 DEBUG("DFU: Block %u -> %08x\n", prog.blocknum, (uint) baseaddr);
 138                 flash_erase_page(baseaddr);
 139                 for (uint i = 0; i < prog.len; i += 2) {
 140                         u16 *dat = (u16 *)(prog.buf + i);
 141                         flash_program_half_word(baseaddr + i, *dat);
 142                 }
 143                 flash_lock();
 144                 usbdfu_state = STATE_DFU_DNLOAD_IDLE;
 145                 return;
 146                 }
 147         case STATE_DFU_MANIFEST:
 148                 /* USB device must detach, we just reset... */
 149                 scb_reset_system();
 150                 return; /* Will never return. */
 151         default:
 152                 return;
 153         }
 154 }
 155
 156 static enum usbd_request_return_codes usbdfu_control_request(usbd_device *usbd_dev,
 157         struct usb_setup_data *req,
 158         byte **buf,
 159         u16 *len,
 160         void (**complete)(usbd_device *usbd_dev, struct usb_setup_data *req))
 161 {
 162         if ((req->bmRequestType & 0x7F) != 0x21)
 163                 return USBD_REQ_NOTSUPP; /* Only accept class request. */
 164
 165         DEBUG("DFU: req %02x in state %d\n", req->bRequest, usbdfu_state);
 166
 167         switch (req->bRequest) {
 168         case DFU_DNLOAD:
 169                 if (len == NULL || *len == 0) {
 170                         usbdfu_state = STATE_DFU_MANIFEST_SYNC;
 171                 } else {
 172                         /* Copy download data for use on GET_STATUS. */
 173                         prog.blocknum = req->wValue;
 174                         prog.len = *len;
 175                         memcpy(prog.buf, *buf, *len);
 176                         usbdfu_state = STATE_DFU_DNLOAD_SYNC;
 177                 }
 178                 return USBD_REQ_HANDLED;
 179         case DFU_CLRSTATUS:
 180                 /* Clear error and return to dfuIDLE. */
 181                 if (usbdfu_state == STATE_DFU_ERROR)
 182                         usbdfu_state = STATE_DFU_IDLE;
 183                 return USBD_REQ_HANDLED;
 184         case DFU_ABORT:
 185                 /* Abort returns to dfuIDLE state. */
 186                 usbdfu_state = STATE_DFU_IDLE;
 187                 return USBD_REQ_HANDLED;
 188         case DFU_UPLOAD:
 189                 /* Upload not supported for now. */
 190                 return USBD_REQ_NOTSUPP;
 191         case DFU_GETSTATUS: {
 192                 u32 bwPollTimeout = 0; /* 24-bit number of milliseconds */
 193                 (*buf)[0] = usbdfu_getstatus(usbd_dev, &bwPollTimeout);
 194                 (*buf)[1] = bwPollTimeout & 0xFF;
 195                 (*buf)[2] = (bwPollTimeout >> 8) & 0xFF;
 196                 (*buf)[3] = (bwPollTimeout >> 16) & 0xFF;
 197                 (*buf)[4] = usbdfu_state;
 198                 (*buf)[5] = 0; /* iString not used here */
 199                 *len = 6;
 200                 *complete = usbdfu_getstatus_complete;
 201                 return USBD_REQ_HANDLED;
 202                 }
 203         case DFU_GETSTATE:
 204                 /* Return state with no state transition. */
 205                 *buf[0] = usbdfu_state;
 206                 *len = 1;
 207                 return USBD_REQ_HANDLED;
 208         }
 209
 210         return USBD_REQ_NOTSUPP;
 211 }
 212
 213 static void usbdfu_set_config(usbd_device *usbd_dev, u16 wValue UNUSED)
 214 {
 215         usbd_register_control_callback(
 216                                 usbd_dev,
 217                                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 218                                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 219                                 usbdfu_control_request);
 220 }
 221
 222 static void usbdfu_reset(void)
 223 {
 224         usbdfu_state = STATE_DFU_IDLE;
 225 }
 226
 227 int main(void)
 228 {
 229         usbd_device *usbd_dev;
 230
 231         // Flash programming requires running on the internal oscillator
 232         rcc_clock_setup_in_hsi_out_48mhz();
 233
 234         rcc_periph_clock_enable(RCC_GPIOA);
 235         rcc_periph_clock_enable(RCC_GPIOC);
 236         rcc_periph_clock_enable(RCC_USB);
 237
 238         rcc_periph_reset_pulse(RST_GPIOA);
 239         rcc_periph_reset_pulse(RST_GPIOC);
 240         rcc_periph_reset_pulse(RST_USB);
 241
 242 #ifdef DEBUG_USART
 243         // Currently, only USART1 is supported
 244         rcc_periph_clock_enable(RCC_USART1);
 245         rcc_periph_reset_pulse(RST_USART1);
 246         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
 247
 248         usart_set_baudrate(USART1, 115200);
 249         usart_set_databits(USART1, 8);
 250         usart_set_stopbits(USART1, USART_STOPBITS_1);
 251         usart_set_mode(USART1, USART_MODE_TX);
 252         usart_set_parity(USART1, USART_PARITY_NONE);
 253         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
 254
 255         usart_enable(USART1);
 256 #endif
 257
 258 #ifdef DEBUG_LED_BLUEPILL
 259         // BluePill LED
 260         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
 261         debug_led(1);
 262 #endif
 263
 264         // Systick: set to overflow in 1 ms, will use only the overflow flag, no interrupts
 265         systick_set_frequency(1000, CPU_CLOCK_MHZ * 1000000);
 266         systick_clear();
 267         systick_counter_enable();
 268
 269         desig_get_unique_id_as_dfu(usb_serial_number);
 270
 271         DEBUG("DFU: Entered boot-loader (SN %s)\n", usb_serial_number);
 272
 273         // Simulate USB disconnect
 274         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 275         gpio_clear(GPIOA, GPIO11 | GPIO12);
 276         for (uint i=0; i<1000; i++) {
 277                 while (!systick_get_countflag())
 278                         ;
 279         }
 280
 281         DEBUG("DFU: Ready\n");
 282         debug_led(0);
 283
 284         usbd_dev = usbd_init(&st_usbfs_v1_usb_driver, &dev, &config, usb_strings, ARRAY_SIZE(usb_strings), usbd_control_buffer, sizeof(usbd_control_buffer));
 285         usbd_register_reset_callback(usbd_dev, usbdfu_reset);
 286         usbd_register_set_config_callback(usbd_dev, usbdfu_set_config);
 287
 288 restart: ;
 289
 290         uint timeout = 5000;
 291         while (timeout) {
 292                 usbd_poll(usbd_dev);
 293                 if (systick_get_countflag()) {
 294                         timeout--;
 295                         if (!(timeout & 0x3f))
 296                                 debug_led_toggle();
 297                 }
 298         }
 299
 300         volatile u32 *app = (volatile u32 *) BOOTLOADER_APP_START;
 301         u32 sp = app[0];
 302         u32 pc = app[1];
 303
 304         DEBUG("DFU: Starting application (sp=%08x, pc=%08x)\n", (uint) sp, (uint) pc);
 305         if (sp & 0x2ffe0000 != 0x20000000) {
 306                 DEBUG("DFU: Suspicious SP, refusing to start\n");
 307                 goto restart;
 308         }
 309
 310 #ifdef DEBUG_USART
 311         while (!usart_get_flag(DEBUG_USART, USART_FLAG_TC))
 312                 ;
 313 #endif
 314         debug_led(0);
 315         cm_disable_interrupts();
 316
 317         /* Set vector table base address. */
 318         SCB_VTOR = BOOTLOADER_APP_START & 0xFFFF;
 319
 320         /* Initialize master stack pointer. */
 321         asm volatile("msr msp, %0"::"g" (sp));
 322
 323         /* Jump to application. */
 324         ((void (*)(void)) pc)();
 325 }