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 struct prog_info {
  39         byte buf[sizeof(usbd_control_buffer)];
  40         u16 blocknum;
  41         u16 len;
  42 };
  43
  44 static struct prog_info prog_page;
  45
  46 // The first page of application code is programmed last,
  47 // so that we are able to detect incompletely uploaded firmware.
  48 static struct prog_info prog_header;
  49
  50 static char usb_serial_number[13];
  51
  52 enum usb_string {
  53         STR_MANUFACTURER = 1,
  54         STR_PRODUCT,
  55         STR_SERIAL,
  56 };
  57
  58 static const char *usb_strings[] = {
  59         BOOTLOADER_MFG_NAME,
  60         BOOTLOADER_PROD_NAME,
  61         usb_serial_number,
  62 };
  63
  64 const struct usb_device_descriptor dev = {
  65         .bLength = USB_DT_DEVICE_SIZE,
  66         .bDescriptorType = USB_DT_DEVICE,
  67         .bcdUSB = 0x0200,
  68         .bDeviceClass = 0,
  69         .bDeviceSubClass = 0,
  70         .bDeviceProtocol = 0,
  71         .bMaxPacketSize0 = 64,
  72         .idVendor = BOOTLOADER_MFG_ID,
  73         .idProduct = BOOTLOADER_PROD_ID,
  74         .bcdDevice = BOOTLOADER_PROD_VERSION,
  75         .iManufacturer = STR_MANUFACTURER,
  76         .iProduct = STR_PRODUCT,
  77         .iSerialNumber = STR_SERIAL,
  78         .bNumConfigurations = 1,
  79 };
  80
  81 const struct usb_dfu_descriptor dfu_function = {
  82         .bLength = sizeof(struct usb_dfu_descriptor),
  83         .bDescriptorType = DFU_FUNCTIONAL,
  84         .bmAttributes = USB_DFU_CAN_DOWNLOAD | USB_DFU_WILL_DETACH,
  85         .wDetachTimeout = 255,
  86         .wTransferSize = 1024,
  87         .bcdDFUVersion = 0x0100,
  88 };
  89
  90 const struct usb_interface_descriptor iface = {
  91         .bLength = USB_DT_INTERFACE_SIZE,
  92         .bDescriptorType = USB_DT_INTERFACE,
  93         .bInterfaceNumber = 0,
  94         .bAlternateSetting = 0,
  95         .bNumEndpoints = 0,
  96         .bInterfaceClass = 0xFE, /* Device Firmware Upgrade */
  97         .bInterfaceSubClass = 1,
  98         .bInterfaceProtocol = 2,
  99         .extra = &dfu_function,
 100         .extralen = sizeof(dfu_function),
 101 };
 102
 103 const struct usb_interface ifaces[] = {{
 104         .num_altsetting = 1,
 105         .altsetting = &iface,
 106 }};
 107
 108 const struct usb_config_descriptor config = {
 109         .bLength = USB_DT_CONFIGURATION_SIZE,
 110         .bDescriptorType = USB_DT_CONFIGURATION,
 111         .wTotalLength = 0,
 112         .bNumInterfaces = 1,
 113         .bConfigurationValue = 1,
 114         .iConfiguration = 0,
 115         .bmAttributes = USB_CONFIG_ATTR_DEFAULT,        // bus-powered
 116         .bMaxPower = 50,                                // multiplied by 2 mA
 117         .interface = ifaces,
 118 };
 119
 120 static byte usbdfu_getstatus(usbd_device *usbd_dev UNUSED, u32 *bwPollTimeout)
 121 {
 122         switch (usbdfu_state) {
 123         case STATE_DFU_DNLOAD_SYNC:
 124                 usbdfu_state = STATE_DFU_DNBUSY;
 125                 *bwPollTimeout = 100;
 126                 return DFU_STATUS_OK;
 127         case STATE_DFU_MANIFEST_SYNC:
 128                 /* Device will reset when read is complete. */
 129                 usbdfu_state = STATE_DFU_MANIFEST;
 130                 return DFU_STATUS_OK;
 131         default:
 132                 return DFU_STATUS_OK;
 133         }
 134 }
 135
 136 static void program_page(struct prog_info *prog, bool need_erase)
 137 {
 138         flash_unlock();
 139         u32 baseaddr = BOOTLOADER_APP_START + prog->blocknum * dfu_function.wTransferSize;
 140         DEBUG("DFU: Block %u -> %08x\n", prog->blocknum, (uint) baseaddr);
 141         if (need_erase)
 142                 flash_erase_page(baseaddr);
 143         for (uint i = 0; i < prog->len; i += 2) {
 144                 u16 data = *(u16 *)(prog->buf + i);
 145                 flash_program_half_word(baseaddr + i, data);
 146         }
 147         flash_lock();
 148 }
 149
 150 static void usbdfu_getstatus_complete(usbd_device *usbd_dev UNUSED, struct usb_setup_data *req UNUSED)
 151 {
 152         switch (usbdfu_state) {
 153         case STATE_DFU_DNBUSY:
 154                 if (prog_page.blocknum == 0) {
 155                         // The first block will be programmed last
 156                         prog_header = prog_page;
 157                         flash_unlock();
 158                         flash_erase_page(BOOTLOADER_APP_START);
 159                         flash_lock();
 160                 } else
 161                         program_page(&prog_page, true);
 162                 usbdfu_state = STATE_DFU_DNLOAD_IDLE;
 163                 return;
 164         case STATE_DFU_MANIFEST:
 165                 // At the very end, program the first page
 166                 program_page(&prog_header, false);
 167                 /* USB device must detach, we just reset... */
 168                 scb_reset_system();
 169                 return; /* Will never return. */
 170         default:
 171                 return;
 172         }
 173 }
 174
 175 static enum usbd_request_return_codes usbdfu_control_request(usbd_device *usbd_dev,
 176         struct usb_setup_data *req,
 177         byte **buf,
 178         u16 *len,
 179         void (**complete)(usbd_device *usbd_dev, struct usb_setup_data *req))
 180 {
 181         if ((req->bmRequestType & 0x7F) != 0x21)
 182                 return USBD_REQ_NOTSUPP; /* Only accept class request. */
 183
 184         DEBUG("DFU: Request %02x in state %d\n", req->bRequest, usbdfu_state);
 185
 186         switch (req->bRequest) {
 187         case DFU_DNLOAD:
 188                 if (len == NULL || *len == 0) {
 189                         usbdfu_state = STATE_DFU_MANIFEST_SYNC;
 190                 } else {
 191                         /* Copy download data for use on GET_STATUS. */
 192                         prog_page.blocknum = req->wValue;
 193                         prog_page.len = *len;
 194                         memcpy(prog_page.buf, *buf, *len);
 195                         usbdfu_state = STATE_DFU_DNLOAD_SYNC;
 196                 }
 197                 return USBD_REQ_HANDLED;
 198         case DFU_CLRSTATUS:
 199                 /* Clear error and return to dfuIDLE. */
 200                 if (usbdfu_state == STATE_DFU_ERROR)
 201                         usbdfu_state = STATE_DFU_IDLE;
 202                 return USBD_REQ_HANDLED;
 203         case DFU_ABORT:
 204                 /* Abort returns to dfuIDLE state. */
 205                 usbdfu_state = STATE_DFU_IDLE;
 206                 return USBD_REQ_HANDLED;
 207         case DFU_UPLOAD:
 208                 /* Upload not supported for now. */
 209                 return USBD_REQ_NOTSUPP;
 210         case DFU_GETSTATUS: {
 211                 u32 bwPollTimeout = 0; /* 24-bit number of milliseconds */
 212                 (*buf)[0] = usbdfu_getstatus(usbd_dev, &bwPollTimeout);
 213                 (*buf)[1] = bwPollTimeout & 0xFF;
 214                 (*buf)[2] = (bwPollTimeout >> 8) & 0xFF;
 215                 (*buf)[3] = (bwPollTimeout >> 16) & 0xFF;
 216                 (*buf)[4] = usbdfu_state;
 217                 (*buf)[5] = 0; /* iString not used here */
 218                 *len = 6;
 219                 *complete = usbdfu_getstatus_complete;
 220                 return USBD_REQ_HANDLED;
 221                 }
 222         case DFU_GETSTATE:
 223                 /* Return state with no state transition. */
 224                 *buf[0] = usbdfu_state;
 225                 *len = 1;
 226                 return USBD_REQ_HANDLED;
 227         }
 228
 229         return USBD_REQ_NOTSUPP;
 230 }
 231
 232 static void usbdfu_set_config(usbd_device *usbd_dev, u16 wValue UNUSED)
 233 {
 234         usbd_register_control_callback(
 235                                 usbd_dev,
 236                                 USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE,
 237                                 USB_REQ_TYPE_TYPE | USB_REQ_TYPE_RECIPIENT,
 238                                 usbdfu_control_request);
 239 }
 240
 241 static void usbdfu_reset(void)
 242 {
 243         usbdfu_state = STATE_DFU_IDLE;
 244 }
 245
 246 int main(void)
 247 {
 248         usbd_device *usbd_dev;
 249
 250         // Flash programming requires running on the internal oscillator
 251         rcc_clock_setup_in_hsi_out_48mhz();
 252
 253         rcc_periph_clock_enable(RCC_GPIOA);
 254         rcc_periph_clock_enable(RCC_GPIOC);
 255         rcc_periph_clock_enable(RCC_USB);
 256
 257         rcc_periph_reset_pulse(RST_GPIOA);
 258         rcc_periph_reset_pulse(RST_GPIOC);
 259         rcc_periph_reset_pulse(RST_USB);
 260
 261 #ifdef DEBUG_USART
 262         // Currently, only USART1 is supported
 263         rcc_periph_clock_enable(RCC_USART1);
 264         rcc_periph_reset_pulse(RST_USART1);
 265         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO9);
 266
 267         usart_set_baudrate(USART1, 115200);
 268         usart_set_databits(USART1, 8);
 269         usart_set_stopbits(USART1, USART_STOPBITS_1);
 270         usart_set_mode(USART1, USART_MODE_TX);
 271         usart_set_parity(USART1, USART_PARITY_NONE);
 272         usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
 273
 274         usart_enable(USART1);
 275 #endif
 276
 277 #ifdef DEBUG_LED_BLUEPILL
 278         // BluePill LED
 279         gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
 280         debug_led(1);
 281 #endif
 282
 283         // Systick: set to overflow in 1 ms, will use only the overflow flag, no interrupts
 284         systick_set_frequency(1000, CPU_CLOCK_MHZ * 1000000);
 285         systick_clear();
 286         systick_counter_enable();
 287
 288         desig_get_unique_id_as_dfu(usb_serial_number);
 289
 290         DEBUG("DFU: Entered boot-loader (SN %s)\n", usb_serial_number);
 291
 292         // Simulate USB disconnect
 293         gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO11 | GPIO12);
 294         gpio_clear(GPIOA, GPIO11 | GPIO12);
 295         for (uint i=0; i<100; i++) {
 296                 while (!systick_get_countflag())
 297                         ;
 298         }
 299
 300         DEBUG("DFU: Ready\n");
 301         debug_led(0);
 302
 303         usbd_dev = usbd_init(&st_usbfs_v1_usb_driver, &dev, &config, usb_strings, ARRAY_SIZE(usb_strings), usbd_control_buffer, sizeof(usbd_control_buffer));
 304         usbd_register_reset_callback(usbd_dev, usbdfu_reset);
 305         usbd_register_set_config_callback(usbd_dev, usbdfu_set_config);
 306
 307 restart: ;
 308
 309         uint timeout = 5000;
 310         while (timeout) {
 311                 usbd_poll(usbd_dev);
 312                 if (systick_get_countflag()) {
 313                         timeout--;
 314                         if (!(timeout & 0x3f))
 315                                 debug_led_toggle();
 316                 }
 317         }
 318
 319         volatile u32 *app = (volatile u32 *) BOOTLOADER_APP_START;
 320         u32 sp = app[0];
 321         u32 pc = app[1];
 322
 323         DEBUG("DFU: Starting application (sp=%08x, pc=%08x)\n", (uint) sp, (uint) pc);
 324         if ((sp & 0x2ffe0000) != 0x20000000) {
 325                 DEBUG("DFU: Suspicious SP, refusing to start\n");
 326                 goto restart;
 327         }
 328
 329 #ifdef DEBUG_USART
 330         while (!usart_get_flag(DEBUG_USART, USART_FLAG_TC))
 331                 ;
 332 #endif
 333         debug_led(0);
 334         cm_disable_interrupts();
 335
 336         /* Set vector table base address. */
 337         SCB_VTOR = BOOTLOADER_APP_START & 0xFFFF;
 338
 339         /* Initialize master stack pointer. */
 340         asm volatile("msr msp, %0"::"g" (sp));
 341
 342         /* Jump to application. */
 343         ((void (*)(void)) pc)();
 344 }