Bootloaders/HID/BootloaderHID.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2018.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2018  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaims all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Main source file for the HID class bootloader. This file contains the complete bootloader logic.
  34  */
  35
  36 #include "BootloaderHID.h"
  37
  38 /** Flag to indicate if the bootloader should be running, or should exit and allow the application code to run
  39  *  via a soft reset. When cleared, the bootloader will abort, the USB interface will shut down and the application
  40  *  started via a forced watchdog reset.
  41  */
  42 static bool RunBootloader = true;
  43
  44 /** Magic lock for forced application start. If the HWBE fuse is programmed and BOOTRST is unprogrammed, the bootloader
  45  *  will start if the /HWB line of the AVR is held low and the system is reset. However, if the /HWB line is still held
  46  *  low when the application attempts to start via a watchdog reset, the bootloader will re-start. If set to the value
  47  *  \ref MAGIC_BOOT_KEY the special init function \ref Application_Jump_Check() will force the application to start.
  48  */
  49 uint16_t MagicBootKey ATTR_NO_INIT;
  50
  51
  52 /** Special startup routine to check if the bootloader was started via a watchdog reset, and if the magic application
  53  *  start key has been loaded into \ref MagicBootKey. If the bootloader started via the watchdog and the key is valid,
  54  *  this will force the user application to start via a software jump.
  55  */
  56 void Application_Jump_Check(void)
  57 {
  58         /* If the reset source was the bootloader and the key is correct, clear it and jump to the application */
  59         if ((MCUSR & (1 << WDRF)) && (MagicBootKey == MAGIC_BOOT_KEY))
  60         {
  61                 /* Turn off the watchdog */
  62                 MCUSR &= ~(1 << WDRF);
  63                 wdt_disable();
  64
  65                 /* Clear the boot key and jump to the user application */
  66                 MagicBootKey = 0;
  67
  68                 // cppcheck-suppress constStatement
  69                 ((void (*)(void))0x0000)();
  70         }
  71 }
  72
  73 /** Main program entry point. This routine configures the hardware required by the bootloader, then continuously
  74  *  runs the bootloader processing routine until instructed to soft-exit.
  75  */
  76 int main(void)
  77 {
  78         /* Setup hardware required for the bootloader */
  79         SetupHardware();
  80
  81         /* Enable global interrupts so that the USB stack can function */
  82         GlobalInterruptEnable();
  83
  84         while (RunBootloader)
  85           USB_USBTask();
  86
  87         /* Wait a short time to end all USB transactions and then disconnect */
  88         _delay_us(1000);
  89
  90         /* Disconnect from the host - USB interface will be reset later along with the AVR */
  91         USB_Detach();
  92
  93         /* Unlock the forced application start mode of the bootloader if it is restarted */
  94         MagicBootKey = MAGIC_BOOT_KEY;
  95
  96         /* Enable the watchdog and force a timeout to reset the AVR */
  97         wdt_enable(WDTO_250MS);
  98
  99         for (;;);
 100 }
 101
 102 /** Configures all hardware required for the bootloader. */
 103 static void SetupHardware(void)
 104 {
 105         /* Disable watchdog if enabled by bootloader/fuses */
 106         MCUSR &= ~(1 << WDRF);
 107         wdt_disable();
 108
 109         /* Disable clock division */
 110         clock_prescale_set(clock_div_1);
 111
 112         /* Relocate the interrupt vector table to the bootloader section */
 113         MCUCR = (1 << IVCE);
 114         MCUCR = (1 << IVSEL);
 115
 116         /* Initialize USB subsystem */
 117         USB_Init();
 118 }
 119
 120 /** Event handler for the USB_ConfigurationChanged event. This configures the device's endpoints ready
 121  *  to relay data to and from the attached USB host.
 122  */
 123 void EVENT_USB_Device_ConfigurationChanged(void)
 124 {
 125         /* Setup HID Report Endpoint */
 126         Endpoint_ConfigureEndpoint(HID_IN_EPADDR, EP_TYPE_INTERRUPT, HID_IN_EPSIZE, 1);
 127 }
 128
 129 /** Event handler for the USB_ControlRequest event. This is used to catch and process control requests sent to
 130  *  the device from the USB host before passing along unhandled control requests to the library for processing
 131  *  internally.
 132  */
 133 void EVENT_USB_Device_ControlRequest(void)
 134 {
 135         /* Ignore any requests that aren't directed to the HID interface */
 136         if ((USB_ControlRequest.bmRequestType & (CONTROL_REQTYPE_TYPE | CONTROL_REQTYPE_RECIPIENT)) !=
 137             (REQTYPE_CLASS | REQREC_INTERFACE))
 138         {
 139                 return;
 140         }
 141
 142         /* Process HID specific control requests */
 143         switch (USB_ControlRequest.bRequest)
 144         {
 145                 case HID_REQ_SetReport:
 146                         Endpoint_ClearSETUP();
 147
 148                         /* Wait until the command has been sent by the host */
 149                         while (!(Endpoint_IsOUTReceived()));
 150
 151                         /* Read in the write destination address */
 152                         #if (FLASHEND > 0xFFFF)
 153                         uint32_t PageAddress = ((uint32_t)Endpoint_Read_16_LE() << 8);
 154                         #else
 155                         uint16_t PageAddress = Endpoint_Read_16_LE();
 156                         #endif
 157
 158                         /* Determine if the given page address is correctly aligned to the
 159                            start of a flash page. */
 160                         bool PageAddressIsAligned = !(PageAddress & (SPM_PAGESIZE - 1));
 161
 162                         /* Check if the command is a program page command, or a start application command */
 163                         #if (FLASHEND > 0xFFFF)
 164                         if ((uint16_t)(PageAddress >> 8) == COMMAND_STARTAPPLICATION)
 165                         #else
 166                         if (PageAddress == COMMAND_STARTAPPLICATION)
 167                         #endif
 168                         {
 169                                 RunBootloader = false;
 170                         }
 171                         else if ((PageAddress < BOOT_START_ADDR) && PageAddressIsAligned)
 172                         {
 173                                 /* Erase the given FLASH page, ready to be programmed */
 174                                 ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
 175                                 {
 176                                         boot_page_erase(PageAddress);
 177                                         boot_spm_busy_wait();
 178                                 }
 179
 180                                 /* Write each of the FLASH page's bytes in sequence */
 181                                 for (uint8_t PageWord = 0; PageWord < (SPM_PAGESIZE / 2); PageWord++)
 182                                 {
 183                                         /* Check if endpoint is empty - if so clear it and wait until ready for next packet */
 184                                         if (!(Endpoint_BytesInEndpoint()))
 185                                         {
 186                                                 Endpoint_ClearOUT();
 187                                                 while (!(Endpoint_IsOUTReceived()));
 188                                         }
 189
 190                                         /* Write the next data word to the FLASH page */
 191                                         boot_page_fill(PageAddress + ((uint16_t)PageWord << 1), Endpoint_Read_16_LE());
 192                                 }
 193
 194                                 /* Write the filled FLASH page to memory */
 195                                 ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
 196                                 {
 197                                         boot_page_write(PageAddress);
 198                                         boot_spm_busy_wait();
 199                                 }
 200
 201                                 /* Re-enable RWW section */
 202                                 boot_rww_enable();
 203                         }
 204
 205                         Endpoint_ClearOUT();
 206
 207                         Endpoint_ClearStatusStage();
 208                         break;
 209         }
 210 }
 211