3 * This file contains special DoxyGen information for the generation of the main page and other special
4 * documentation pages. It is not a project source file.
7 /** \mainpage Mass Storage Class USB AVR Bootloader
9 * \section Sec_Compat Demo Compatibility:
11 * The following list indicates what microcontrollers are compatible with this demo.
13 * \li Series 7 USB AVRs (AT90USBxxx7)
14 * \li Series 6 USB AVRs (AT90USBxxx6)
15 * \li Series 4 USB AVRs (ATMEGAxxU4) - <i>See \ref SSec_Aux_Space</i>
16 * \li ATMEGA32U2 - <i>See \ref SSec_Aux_Space</i>
18 * \section Sec_Info USB Information:
20 * The following table gives a rundown of the USB utilization of this demo.
24 * <td><b>USB Mode:</b></td>
28 * <td><b>USB Class:</b></td>
29 * <td>Mass Storage Device</td>
32 * <td><b>USB Subclass:</b></td>
33 * <td>Bulk-Only Transport</td>
36 * <td><b>Relevant Standards:</b></td>
37 * <td>USBIF Mass Storage Standard \n
38 * USB Bulk-Only Transport Standard \n
39 * SCSI Primary Commands Specification \n
40 * SCSI Block Commands Specification</td>
43 * <td><b>Supported USB Speeds:</b></td>
44 * <td>Full Speed Mode</td>
48 * \section Sec_Description Project Description:
50 * This bootloader enumerates to the host as a Mass Storage device, capable of reading and writing a new binary
51 * firmware image file, to load firmware onto the AVR.
53 * Out of the box this bootloader builds for the AT90USB1287 with an 8KB bootloader section size, and will fit
54 * into 6KB of bootloader space. If you wish to alter this size and/or change the AVR model, you will need to
55 * edit the MCU, FLASH_SIZE_KB and BOOT_SECTION_SIZE_KB values in the accompanying makefile.
57 * When the bootloader is running, the board's LED(s) will flash at regular intervals to distinguish the
58 * bootloader from the normal user application.
60 * \warning <b>THIS BOOTLOADER IS NOT SECURE.</b> Malicious entities can recover written data, even if the device
63 * \section Sec_Running Running the Bootloader
65 * This bootloader is designed to be started via the HWB mechanism of the USB AVRs; ground the HWB pin (see device
66 * datasheet) then momentarily ground /RESET to start the bootloader. This assumes the HWBE fuse is set and the BOOTRST
69 * For board specific exceptions to the above, see below.
71 * \subsection SSec_XPLAIN Atmel Xplain Board
72 * Ground the USB AVR JTAG's \c TCK pin to ground when powering on the board to start the bootloader. This assumes the
73 * \c HWBE fuse is cleared and the \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
75 * \subsection SSec_Leonardo Arduino Leonardo Board
76 * Ground \c IO13 when powering the board to start the bootloader. This assumes the \c HWBE fuse is cleared and the
77 * \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board.
79 * \section Sec_Installation Driver Installation
81 * This bootloader uses the Mass Storage drivers inbuilt into all modern operating systems, thus no additional
82 * drivers need to be supplied for correct operation.
84 * \section Sec_HostApp Host Controller Application
86 * This bootloader is compatible with all operating systems that support the FAT12 file system format. To reprogram the
87 * device, overwrite a file stored on the virtual FAT filesystem with a new binary (BIN format) image. Remember to safely
88 * remove your device from the host using the host OS's ejection APIs, to ensure all data is correctly flushed to the
89 * bootloader's virtual filesystem and not cached in the OS's file system driver.
91 * The current device firmware can be read from the device by reading a file from the virtual FAT filesystem.
93 * \warning This bootloader is currently <b>incompatible with the Apple MacOS X OS Finder GUI</b>, due to the
94 * large amount of meta files this OS attempts to write to the disk along with the new binaries. On
95 * this platform, firmwares must be copied to the disk via the Terminal application only to prevent
96 * firmware corruption.
98 * \section Sec_API User Application API
100 * Several user application functions for FLASH and other special memory area manipulations are exposed by the bootloader,
101 * allowing the user application to call into the bootloader at runtime to read and write FLASH data.
103 * By default, the bootloader API jump table is located 32 bytes from the end of the device's FLASH memory, and follows the
107 * #define BOOTLOADER_API_TABLE_SIZE 32
108 * #define BOOTLOADER_API_TABLE_START ((FLASHEND + 1UL) - BOOTLOADER_API_TABLE_SIZE)
109 * #define BOOTLOADER_API_CALL(Index) (void*)((BOOTLOADER_API_TABLE_START + (Index * 2)) / 2)
111 * void (*BootloaderAPI_ErasePage)(uint32_t Address) = BOOTLOADER_API_CALL(0);
112 * void (*BootloaderAPI_WritePage)(uint32_t Address) = BOOTLOADER_API_CALL(1);
113 * void (*BootloaderAPI_FillWord)(uint32_t Address, uint16_t Word) = BOOTLOADER_API_CALL(2);
114 * uint8_t (*BootloaderAPI_ReadSignature)(uint16_t Address) = BOOTLOADER_API_CALL(3);
115 * uint8_t (*BootloaderAPI_ReadFuse)(uint16_t Address) = BOOTLOADER_API_CALL(4);
116 * uint8_t (*BootloaderAPI_ReadLock)(void) = BOOTLOADER_API_CALL(5);
117 * void (*BootloaderAPI_WriteLock)(uint8_t LockBits) = BOOTLOADER_API_CALL(6);
119 * #define BOOTLOADER_MAGIC_SIGNATURE_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 2))
120 * #define BOOTLOADER_MAGIC_SIGNATURE 0xDCFB
122 * #define BOOTLOADER_CLASS_SIGNATURE_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 4))
123 * #define BOOTLOADER_MASS_STORAGE_SIGNATURE 0xDF30
125 * #define BOOTLOADER_ADDRESS_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 8))
126 * #define BOOTLOADER_ADDRESS_LENGTH 4
129 * From the application the API support of the bootloader can be detected by reading the FLASH memory bytes located at address
130 * \c BOOTLOADER_MAGIC_SIGNATURE_START and comparing them to the value \c BOOTLOADER_MAGIC_SIGNATURE. The class of bootloader
131 * can be determined by reading the FLASH memory bytes located at address \c BOOTLOADER_CLASS_SIGNATURE_START and comparing them
132 * to the value \c BOOTLOADER_MASS_STORAGE_SIGNATURE. The start address of the bootloader can be retrieved by reading the bytes
133 * of FLASH memory starting from address \c BOOTLOADER_ADDRESS_START.
135 * \subsection SSec_Aux_Space Auxiliary Bootloader Section
136 * To make the bootloader function on smaller devices (those with a physical bootloader section of smaller than 6KB) a second
137 * section of memory (called the <i>Auxiliary Bootloader Section</i>) is added before the start of the real bootloader section,
138 * and is filled with a portion of the bootloader code. This allows smaller devices to run the bootloader, at the cost of an
139 * additional portion of the device's FLASH (the bootloader section size in KB subtracted from the 6KB total size). A small
140 * trampoline is inserted at the start of the auxiliary section so that the bootloader will run normally in the case of a blank
141 * application section.
143 * On devices supporting a 8KB bootloader section size, the AUX section is not created in the final binary.
145 * \subsection SSec_API_MemLayout Device Memory Map
146 * The following illustration indicates the final memory map of the device when loaded with the bootloader.
149 * +----------------------------+ 0x0000
158 * | User Application |
167 * +----------------------------+ FLASHEND - BOOT_SECTION_SIZE - BOOT_AUX_SECTION_SIZE
168 * | Booloader Start Trampoline |
169 * | (Not User App. Accessible) |
170 * +----------------------------+ FLASHEND - BOOT_SECTION_SIZE - BOOT_AUX_SECTION_SIZE + 4
172 * | Auxiliary Bootloader |
173 * | Space for Smaller Devices |
174 * | (Not User App. Accessible) |
176 * +----------------------------+ FLASHEND - BOOT_SECTION_SIZE
178 * | Bootloader Application |
179 * | (Not User App. Accessible) |
181 * +----------------------------+ FLASHEND - 96
182 * | API Table Trampolines |
183 * | (Not User App. Accessible) |
184 * +----------------------------+ FLASHEND - 32
185 * | Bootloader API Table |
186 * | (User App. Accessible) |
187 * +----------------------------+ FLASHEND - 8
188 * | Bootloader ID Constants |
189 * | (User App. Accessible) |
190 * +----------------------------+ FLASHEND
193 * \section Sec_KnownIssues Known Issues:
195 * \par In some cases, the application is not fully loaded into the device.
196 * Write-caching on some operating systems may interfere with the normal
197 * operation of the bootloader. Write caching should be disabled when using the
198 * Mass Storage bootloader, or the file system synced via an appropriate command
199 * (such as the OS's normal disk ejection command) before disconnecting the device.
201 * \par After loading an application, it is not run automatically on startup.
202 * Some USB AVR boards ship with the BOOTRST fuse set, causing the bootloader
203 * to run automatically when the device is reset. In most cases, the BOOTRST
204 * fuse should be disabled and the HWBE fuse used instead to run the bootloader
207 * \section Sec_Options Project Options
209 * The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value.
213 * <th><b>Define Name:</b></th>
214 * <th><b>Location:</b></th>
215 * <th><b>Description:</b></th>
218 * <td>NO_APP_START_ON_EJECT</td>
219 * <td>AppConfig.h</td>
220 * <td>Define to disable automatic start of the loaded application when the virtual
221 * Mass Storage disk is ejected on the host.</td>