/** \file * * This file contains special DoxyGen information for the generation of the main page and other special * documentation pages. It is not a project source file. */ /** \mainpage Mass Storage Class USB AVR Bootloader * * \section Sec_Compat Demo Compatibility: * * The following list indicates what microcontrollers are compatible with this demo. * * \li Series 7 USB AVRs (AT90USBxxx7) * \li Series 6 USB AVRs (AT90USBxxx6) * \li Series 4 USB AVRs (ATMEGAxxU4) - <i>See \ref SSec_Aux_Space</i> * \li ATMEGA32U2 - <i>See \ref SSec_Aux_Space</i> * * \section Sec_Info USB Information: * * The following table gives a rundown of the USB utilization of this demo. * * <table> * <tr> * <td><b>USB Mode:</b></td> * <td>Device</td> * </tr> * <tr> * <td><b>USB Class:</b></td> * <td>Mass Storage Device</td> * </tr> * <tr> * <td><b>USB Subclass:</b></td> * <td>Bulk-Only Transport</td> * </tr> * <tr> * <td><b>Relevant Standards:</b></td> * <td>USBIF Mass Storage Standard \n * USB Bulk-Only Transport Standard \n * SCSI Primary Commands Specification \n * SCSI Block Commands Specification</td> * </tr> * <tr> * <td><b>Supported USB Speeds:</b></td> * <td>Full Speed Mode</td> * </tr> * </table> * * \section Sec_Description Project Description: * * This bootloader enumerates to the host as a Mass Storage device, capable of reading and writing a new binary * firmware image file, to load firmware onto the AVR. * * Out of the box this bootloader builds for the AT90USB1287 with an 8KB bootloader section size, and will fit * into 6KB of bootloader space. If you wish to alter this size and/or change the AVR model, you will need to * edit the MCU, FLASH_SIZE_KB and BOOT_SECTION_SIZE_KB values in the accompanying makefile. * * When the bootloader is running, the board's LED(s) will flash at regular intervals to distinguish the * bootloader from the normal user application. * * \warning <b>THIS BOOTLOADER IS NOT SECURE.</b> Malicious entities can recover written data, even if the device * lockbits are set. * * \section Sec_Running Running the Bootloader * * On the USB AVR8 devices, setting the \c HWBE device fuse will cause the bootloader to run if the \c HWB pin of * the AVR is grounded when the device is reset. * * The are two behaviours of this bootloader, depending on the device's fuses: * * <b>If the device's BOOTRST fuse is set</b>, the bootloader will run any time the system is reset from * the external reset pin, unless no valid user application has been loaded. To initiate the bootloader, the * device's external reset pin should be grounded momentarily. * * <b>If the device's BOOTRST fuse is not set</b>, the bootloader will run only if initiated via a software * jump, or if the \c HWB pin was low during the last device reset (if the \c HWBE fuse is set). * * For board specific exceptions to the above, see below. * * \subsection SSec_XPLAIN Atmel Xplain Board * Ground the USB AVR JTAG's \c TCK pin to ground when powering on the board to start the bootloader. This assumes the * \c HWBE fuse is cleared and the \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board. * * \subsection SSec_Leonardo Arduino Leonardo Board * Ground \c IO13 when powering the board to start the bootloader. This assumes the \c HWBE fuse is cleared and the * \c BOOTRST fuse is set as the HWBE pin is not user accessible on this board. * * \section Sec_Installation Driver Installation * * This bootloader uses the Mass Storage drivers inbuilt into all modern operating systems, thus no additional * drivers need to be supplied for correct operation. * * \section Sec_HostApp Host Controller Application * * This bootloader is compatible with all operating systems that support the FAT12 file system format. To reprogram the * device, overwrite a file stored on the virtual FAT filesystem with a new binary (BIN format) image. Remember to safely * remove your device from the host using the host OS's ejection APIs, to ensure all data is correctly flushed to the * bootloader's virtual filesystem and not cached in the OS's file system driver. * * The current device firmware can be read from the device by reading a file from the virtual FAT filesystem. Two files will * be present: * - <b>FLASH.BIN</b>, representing the AVR's internal flash memory * - <b>EEPROM.BIN</b>, representing the AVR's internal EEPROM memory * * To convert an existing Intel HEX (.HEX) program file to a binary (.BIN) file suitable for this bootloader, run: * \code * avr-objcopy -O binary -R .eeprom -R .fuse -R .lock -R .signature input.hex output.bin * \endcode * From a terminal, replacing <tt>input.hex</tt> and <tt>output.bin</tt> with the respective input and output filenames. * AVR EEPROM data files in Intel HEX format (.EEP) uses a similar technique: * \code * avr-objcopy -O binary input.eep output.bin * \endcode * * \warning This bootloader is currently <b>incompatible with the Apple MacOS X OS Finder GUI</b>, due to the * large amount of meta files this OS attempts to write to the disk along with the new binaries. On * this platform, firmwares must be copied to the disk via the Terminal application only to prevent * firmware corruption. * * \section Sec_API User Application API * * Several user application functions for FLASH and other special memory area manipulations are exposed by the bootloader, * allowing the user application to call into the bootloader at runtime to read and write FLASH data. * * By default, the bootloader API jump table is located 32 bytes from the end of the device's FLASH memory, and follows the * following layout: * * \code * #define BOOTLOADER_API_TABLE_SIZE 32 * #define BOOTLOADER_API_TABLE_START ((FLASHEND + 1UL) - BOOTLOADER_API_TABLE_SIZE) * #define BOOTLOADER_API_CALL(Index) (void*)((BOOTLOADER_API_TABLE_START + (Index * 2)) / 2) * * void (*BootloaderAPI_ErasePage)(uint32_t Address) = BOOTLOADER_API_CALL(0); * void (*BootloaderAPI_WritePage)(uint32_t Address) = BOOTLOADER_API_CALL(1); * void (*BootloaderAPI_FillWord)(uint32_t Address, uint16_t Word) = BOOTLOADER_API_CALL(2); * uint8_t (*BootloaderAPI_ReadSignature)(uint16_t Address) = BOOTLOADER_API_CALL(3); * uint8_t (*BootloaderAPI_ReadFuse)(uint16_t Address) = BOOTLOADER_API_CALL(4); * uint8_t (*BootloaderAPI_ReadLock)(void) = BOOTLOADER_API_CALL(5); * void (*BootloaderAPI_WriteLock)(uint8_t LockBits) = BOOTLOADER_API_CALL(6); * * #define BOOTLOADER_MAGIC_SIGNATURE_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 2)) * #define BOOTLOADER_MAGIC_SIGNATURE 0xDCFB * * #define BOOTLOADER_CLASS_SIGNATURE_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 4)) * #define BOOTLOADER_MASS_STORAGE_SIGNATURE 0xDF30 * * #define BOOTLOADER_ADDRESS_START (BOOTLOADER_API_TABLE_START + (BOOTLOADER_API_TABLE_SIZE - 8)) * #define BOOTLOADER_ADDRESS_LENGTH 4 * \endcode * * From the application the API support of the bootloader can be detected by reading the FLASH memory bytes located at address * \c BOOTLOADER_MAGIC_SIGNATURE_START and comparing them to the value \c BOOTLOADER_MAGIC_SIGNATURE. The class of bootloader * can be determined by reading the FLASH memory bytes located at address \c BOOTLOADER_CLASS_SIGNATURE_START and comparing them * to the value \c BOOTLOADER_MASS_STORAGE_SIGNATURE. The start address of the bootloader can be retrieved by reading the bytes * of FLASH memory starting from address \c BOOTLOADER_ADDRESS_START. * * \subsection SSec_Aux_Space Auxiliary Bootloader Section * To make the bootloader function on smaller devices (those with a physical bootloader section of smaller than 6KB) a second * section of memory (called the <i>Auxiliary Bootloader Section</i>) is added before the start of the real bootloader section, * and is filled with a portion of the bootloader code. This allows smaller devices to run the bootloader, at the cost of an * additional portion of the device's FLASH (the bootloader section size in KB subtracted from the 6KB total size). A small * trampoline is inserted at the start of the auxiliary section so that the bootloader will run normally in the case of a blank * application section. * * On devices supporting a 8KB bootloader section size, the AUX section is not created in the final binary. * * \subsection SSec_API_MemLayout Device Memory Map * The following illustration indicates the final memory map of the device when loaded with the bootloader. * * \verbatim * +----------------------------+ 0x0000 * | | * | | * | | * | | * | | * | | * | | * | | * | User Application | * | | * | | * | | * | | * | | * | | * | | * | | * +----------------------------+ FLASHEND - BOOT_SECTION_SIZE - BOOT_AUX_SECTION_SIZE * | Booloader Start Trampoline | * | (Not User App. Accessible) | * +----------------------------+ FLASHEND - BOOT_SECTION_SIZE - BOOT_AUX_SECTION_SIZE + 4 * | | * | Auxiliary Bootloader | * | Space for Smaller Devices | * | (Not User App. Accessible) | * | | * +----------------------------+ FLASHEND - BOOT_SECTION_SIZE * | | * | Bootloader Application | * | (Not User App. Accessible) | * | | * +----------------------------+ FLASHEND - 96 * | API Table Trampolines | * | (Not User App. Accessible) | * +----------------------------+ FLASHEND - 32 * | Bootloader API Table | * | (User App. Accessible) | * +----------------------------+ FLASHEND - 8 * | Bootloader ID Constants | * | (User App. Accessible) | * +----------------------------+ FLASHEND * \endverbatim * * \section Sec_KnownIssues Known Issues: * * \par In some cases, the application is not fully loaded into the device. * Write-caching on some operating systems may interfere with the normal * operation of the bootloader. Write caching should be disabled when using the * Mass Storage bootloader, or the file system synced via an appropriate command * (such as the OS's normal disk ejection command) before disconnecting the device. * * \section Sec_Options Project Options * * The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value. * * <table> * <tr> * <th><b>Define Name:</b></th> * <th><b>Location:</b></th> * <th><b>Description:</b></th> * </tr> * <tr> * <td>NO_APP_START_ON_EJECT</td> * <td>AppConfig.h</td> * <td>Define to disable automatic start of the loaded application when the virtual * Mass Storage disk is ejected on the host.</td> * </tr> * </table> */