X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/68c317c4e9b54843fdafa5b0ab1eb19e8ffc37c3..ce546b43cc5e873b7a8f04b973c624fe6f5702ba:/Bootloaders/MassStorage/BootloaderMassStorage.txt diff --git a/Bootloaders/MassStorage/BootloaderMassStorage.txt b/Bootloaders/MassStorage/BootloaderMassStorage.txt index 7ca7c1f85..0b30cbfb6 100644 --- a/Bootloaders/MassStorage/BootloaderMassStorage.txt +++ b/Bootloaders/MassStorage/BootloaderMassStorage.txt @@ -12,6 +12,8 @@ * * \li Series 7 USB AVRs (AT90USBxxx7) * \li Series 6 USB AVRs (AT90USBxxx6) + * \li Series 4 USB AVRs (ATMEGAxxU4) - See \ref SSec_Aux_Space + * \li ATMEGA32U2 - See \ref SSec_Aux_Space * * \section Sec_Info USB Information: * @@ -49,7 +51,7 @@ * 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 8KB of bootloader space. If you wish to alter this size and/or change the AVR model, you will need to + * 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 @@ -69,6 +71,11 @@ * * The current device firmware can be read from the device by reading a file from the virtual FAT filesystem. * + * \warning This bootloader is currently incompatible with the Apple MacOS X OS Finder GUI, 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, @@ -100,6 +107,22 @@ * #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 Auxiliary Bootloader Section) 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. * @@ -121,6 +144,16 @@ * | | * | | * | | + * | | + * +----------------------------+ 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 | @@ -138,11 +171,19 @@ * +----------------------------+ FLASHEND * \endverbatim * - * Bootloaders reporting a device release revision number of 1.00 or greater are bootloader API enabled. 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. + * \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. + * + * \par After loading an application, it is not run automatically on startup. + * Some USB AVR boards ship with the BOOTRST fuse set, causing the bootloader + * to run automatically when the device is reset. In most cases, the BOOTRST + * fuse should be disabled and the HWBE fuse used instead to run the bootloader + * when needed. * * \section Sec_Options Project Options * @@ -150,9 +191,15 @@ * * * - * + * + * + * + * + * + * + * + * * *
- * None - * Define Name:Location:Description:
NO_APP_START_ON_EJECTAppConfig.hDefine to disable automatic start of the loaded application when the virtual + * Mass Storage disk is ejected on the host.
*/