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| 1 | /** \file | ||
| 2 | * | ||
| 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. | ||
| 5 | */ | ||
| 6 | |||
| 7 | /** | ||
| 8 | * \page Page_SoftwareBootloaderStart Entering the Bootloader via Software | ||
| 9 | * | ||
| 10 | * A common requirement of many applications is the ability to jump to the programmed bootloader of a chip | ||
| 11 | * on demand, via the code's firmware (i.e. not as a result of any physical user interaction with the | ||
| 12 | * hardware). This might be required because the device does not have any physical user input, or simply | ||
| 13 | * just to streamline the device upgrade process on the host PC. | ||
| 14 | * | ||
| 15 | * The following C code snippets may be used to enter the bootloader upon request by the user application. | ||
| 16 | * By using the watchdog to physically reset the controller, it is ensured that all system hardware is | ||
| 17 | * completely reset to their defaults before the bootloader is run. This is important; since bootloaders | ||
| 18 | * are written to occupy a very limited space, they usually make assumptions about the register states based | ||
| 19 | * on the default values after a hard-reset of the chip. | ||
| 20 | * | ||
| 21 | * \section Sec_SoftareBootAVR8 AVR8 Architecture | ||
| 22 | * The following software bootloader jump code is written for the AVR8 architecture. | ||
| 23 | * | ||
| 24 | * \code | ||
| 25 | * #include <avr/wdt.h> | ||
| 26 | * #include <avr/io.h> | ||
| 27 | * #include <util/delay.h> | ||
| 28 | * | ||
| 29 | * #include <LUFA/Common/Common.h> | ||
| 30 | * #include <LUFA/Drivers/USB/USB.h> | ||
| 31 | * | ||
| 32 | * uint32_t Boot_Key ATTR_NO_INIT; | ||
| 33 | * | ||
| 34 | * #define MAGIC_BOOT_KEY 0xBADCAFE5 | ||
| 35 | * #define BOOTLOADER_START_ADDRESS ((FLASH_SIZE_BYTES - BOOTLOADER_SEC_SIZE_BYTES) >> 1) | ||
| 36 | * | ||
| 37 | * void Bootloader_Jump_Check(void) ATTR_INIT_SECTION(3); | ||
| 38 | * void Bootloader_Jump_Check(void) | ||
| 39 | * { | ||
| 40 | * // If the reset source was the bootloader and the key is correct, clear it and jump to the bootloader | ||
| 41 | * if ((MCUSR & (1 << WDRF)) && (Boot_Key == MAGIC_BOOT_KEY)) | ||
| 42 | * { | ||
| 43 | * Boot_Key = 0; | ||
| 44 | * ((void (*)(void))BOOTLOADER_START_ADDRESS)(); | ||
| 45 | * } | ||
| 46 | * } | ||
| 47 | * | ||
| 48 | * void Jump_To_Bootloader(void) | ||
| 49 | * { | ||
| 50 | * // If USB is used, detach from the bus and reset it | ||
| 51 | * USB_Disable(); | ||
| 52 | * | ||
| 53 | * // Disable all interrupts | ||
| 54 | * cli(); | ||
| 55 | * | ||
| 56 | * // Wait two seconds for the USB detachment to register on the host | ||
| 57 | * Delay_MS(2000); | ||
| 58 | * | ||
| 59 | * // Set the bootloader key to the magic value and force a reset | ||
| 60 | * Boot_Key = MAGIC_BOOT_KEY; | ||
| 61 | * wdt_enable(WDTO_250MS); | ||
| 62 | * for (;;); | ||
| 63 | * } | ||
| 64 | * \endcode | ||
| 65 | * | ||
| 66 | * Note that the bootloader magic key can be any arbitrary value. The <em>FLASH_SIZE_BYTES</em> and | ||
| 67 | * <em>BOOTLOADER_SEC_SIZE_BYTES</em> tokens should be replaced with the total flash size of the AVR | ||
| 68 | * in bytes, and the allocated size of the bootloader section for the target AVR. | ||
| 69 | * | ||
| 70 | */ | ||
| 71 | |||
