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diff --git a/lib/lufa/LUFA/DoxygenPages/SoftwareBootloaderJump.txt b/lib/lufa/LUFA/DoxygenPages/SoftwareBootloaderJump.txt new file mode 100644 index 0000000000..f8c2523d7b --- /dev/null +++ b/lib/lufa/LUFA/DoxygenPages/SoftwareBootloaderJump.txt @@ -0,0 +1,71 @@ +/** \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. + */ + +/** + * \page Page_SoftwareBootloaderStart Entering the Bootloader via Software + * + * A common requirement of many applications is the ability to jump to the programmed bootloader of a chip + * on demand, via the code's firmware (i.e. not as a result of any physical user interaction with the + * hardware). This might be required because the device does not have any physical user input, or simply + * just to streamline the device upgrade process on the host PC. + * + * The following C code snippets may be used to enter the bootloader upon request by the user application. + * By using the watchdog to physically reset the controller, it is ensured that all system hardware is + * completely reset to their defaults before the bootloader is run. This is important; since bootloaders + * are written to occupy a very limited space, they usually make assumptions about the register states based + * on the default values after a hard-reset of the chip. + * + * \section Sec_SoftareBootAVR8 AVR8 Architecture + * The following software bootloader jump code is written for the AVR8 architecture. + * + * \code + * #include <avr/wdt.h> + * #include <avr/io.h> + * #include <util/delay.h> + * + * #include <LUFA/Common/Common.h> + * #include <LUFA/Drivers/USB/USB.h> + * + * uint32_t Boot_Key ATTR_NO_INIT; + * + * #define MAGIC_BOOT_KEY 0xBADCAFE5 + * #define BOOTLOADER_START_ADDRESS ((FLASH_SIZE_BYTES - BOOTLOADER_SEC_SIZE_BYTES) >> 1) + * + * void Bootloader_Jump_Check(void) ATTR_INIT_SECTION(3); + * void Bootloader_Jump_Check(void) + * { + * // If the reset source was the bootloader and the key is correct, clear it and jump to the bootloader + * if ((MCUSR & (1 << WDRF)) && (Boot_Key == MAGIC_BOOT_KEY)) + * { + * Boot_Key = 0; + * ((void (*)(void))BOOTLOADER_START_ADDRESS)(); + * } + * } + * + * void Jump_To_Bootloader(void) + * { + * // If USB is used, detach from the bus and reset it + * USB_Disable(); + * + * // Disable all interrupts + * cli(); + * + * // Wait two seconds for the USB detachment to register on the host + * Delay_MS(2000); + * + * // Set the bootloader key to the magic value and force a reset + * Boot_Key = MAGIC_BOOT_KEY; + * wdt_enable(WDTO_250MS); + * for (;;); + * } + * \endcode + * + * Note that the bootloader magic key can be any arbitrary value. The <em>FLASH_SIZE_BYTES</em> and + * <em>BOOTLOADER_SEC_SIZE_BYTES</em> tokens should be replaced with the total flash size of the AVR + * in bytes, and the allocated size of the bootloader section for the target AVR. + * + */ + |