diff options
Diffstat (limited to 'LUFA/ManPages')
-rw-r--r-- | LUFA/ManPages/ChangeLog.txt | 1 | ||||
-rw-r--r-- | LUFA/ManPages/DevelopingWithLUFA.txt | 1 | ||||
-rw-r--r-- | LUFA/ManPages/SoftwareBootloaderJump.txt | 63 |
3 files changed, 65 insertions, 0 deletions
diff --git a/LUFA/ManPages/ChangeLog.txt b/LUFA/ManPages/ChangeLog.txt index 57093aeb6..f4c995f17 100644 --- a/LUFA/ManPages/ChangeLog.txt +++ b/LUFA/ManPages/ChangeLog.txt @@ -12,6 +12,7 @@ * - Added incomplete MIDIToneGenerator project
* - Added new Relay Controller Board project (thanks to OBinou)
* - Added board hardware driver support for the Teensy, USBTINY MKII, Benito and JM-DB-U2 lines of third party USB AVR boards
+ * - Added new ATTR_NO_INIT variable attribute
*
* <b>Changed:</b>
* - AVRISP programmer project now has a more robust timeout system, allowing for an increase of the software USART speed
diff --git a/LUFA/ManPages/DevelopingWithLUFA.txt b/LUFA/ManPages/DevelopingWithLUFA.txt index 66c1ed4c6..eb079baab 100644 --- a/LUFA/ManPages/DevelopingWithLUFA.txt +++ b/LUFA/ManPages/DevelopingWithLUFA.txt @@ -16,6 +16,7 @@ * - \subpage Page_VIDPID Allocated USB VID and PID Values
* - \subpage Page_BuildLibrary Building as a Linkable Library
* - \subpage Page_WritingBoardDrivers How to Write Custom Board Drivers
+ * - \subpage Page_SoftwareBootloaderStart How to jump to the bootloader in software
* - \subpage Page_SchedulerOverview Overview of the Simple LUFA Scheduler (DEPRECATED)
*/
\ No newline at end of file diff --git a/LUFA/ManPages/SoftwareBootloaderJump.txt b/LUFA/ManPages/SoftwareBootloaderJump.txt new file mode 100644 index 000000000..afdc0b32a --- /dev/null +++ b/LUFA/ManPages/SoftwareBootloaderJump.txt @@ -0,0 +1,63 @@ +/** \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 snippet 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.
+ *
+ * \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 0xDC42ACCA
+ * #define BOOTLOADER_START_ADDRESS ({FLASH_SIZE_BYTES} - {BOOTLOADER_SEC_SIZE_BYTES})
+ *
+ * int Bootloader_Jump_Check(void) ATTR_INIT_SECTION(3);
+ * int Bootloader_Jump_Check(void)
+ * {
+ * // If the bootloader key is correct, clear it and jump to the bootloader
+ * if (Boot_Key == MAGIC_BOOT_KEY)
+ * {
+ * Boot_Key = 0;
+ * ((void (*)(void))BOOTLOADER_START_ADDRESS)();
+ * }
+ * }
+ *
+ * void Jump_To_Bootloader(void)
+ * {
+ * // If USB is used, detatch from the bus and wait 2 seconds for the host to register it
+ * USB_ShutDown();
+ * for (uint8_t i = 0; i < 128; i++)
+ * _delay_ms(16);
+ *
+ * // 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 {FLASH_SIZE_BYTES} and
+ * {BOOTLOADER_SEC_SIZE_BYTES} 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.
+ *
+ */
\ No newline at end of file |