/** \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_BuildSystem The LUFA Build System * * \section Sec_BuildSystemOverview Overview of the LUFA Build System * The LUFA build system is an attempt at making a set of re-usable, modular build make files which * can be referenced in a LUFA powered project, to minimize the amount of code required in an * application makefile. The system is written in GNU Make, and each module is independent of * one-another. * * For details on the prerequisites needed for Linux and Windows machines to be able to use the LUFA * build system, see \ref Sec_Prerequisites. * * To use a LUFA build system module, simply add an include to your project makefile. All user projects * should at a minimum include \ref Page_BuildModule_CORE for base functionality: * \code * include $(LUFA_PATH)/Build/lufa_core.mk * \endcode * * Once included in your project makefile, the associated build module targets will be added to your * project's build makefile targets automatically. To call a build target, run make {TARGET_NAME} * from the command line, substituting in the appropriate target name. * * \see \ref Sec_AppMakefileParams for a copy of the sample LUFA project makefile. * * Each build module may have one or more mandatory parameters (GNU Make variables) which must * be supplied in the project makefile for the module to work, and one or more optional parameters which * may be defined and which will assume a sensible default if not. * * \section SSec_BuildSystemModules Available Modules * * The following modules are included in this LUFA release: * * \li \subpage Page_BuildModule_ATPROGRAM - Device Programming * \li \subpage Page_BuildModule_AVRDUDE - Device Programming * \li \subpage Page_BuildModule_BUILD - Compiling/Assembling/Linking * \li \subpage Page_BuildModule_CORE - Core Build System Functions * \li \subpage Page_BuildModule_CPPCHECK - Static Code Analysis * \li \subpage Page_BuildModule_DFU - Device Programming * \li \subpage Page_BuildModule_DOXYGEN - Automated Source Code Documentation * \li \subpage Page_BuildModule_HID - Device Programming * \li \subpage Page_BuildModule_SOURCES - LUFA Module Source Code Variables * * If you have problems building using the LUFA build system, see \subpage Page_BuildTroubleshooting for resolution steps. */ /** \page Page_BuildModule_BUILD The BUILD build module * * The BUILD LUFA build system module, providing targets for the compilation, * assembling and linking of an application from source code into binary files * suitable for programming into a target device, using the GCC compiler. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_build.mk * \endcode * * \section SSec_BuildModule_BUILD_Requirements Requirements * This module requires the the architecture appropriate binaries of the GCC compiler are available in your * system's PATH variable. The GCC compiler and associated toolchain is distributed in Atmel AVR Studio * 5.x and Atmel Studio 6.x installation directories, as well as in many third party distribution packages. * * \section SSec_BuildModule_BUILD_Targets Targets * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

`size`	Display size of the compiled application FLASH and SRAM segments.
`symbol-sizes`	Display a size-sorted list of symbols from the compiled application, in decimal bytes.
`lib`	Build and archive all source files into a library A binary file.
`all`	Build and link the application into ELF debug and HEX binary files.
`elf`	Build and link the application into an ELF debug file.
`bin`	Build and link the application and produce a BIN binary file.
`hex`	Build and link the application and produce HEX and EEP binary files.
`lss`	Build and link the application and produce a LSS source code/assembly code mixed listing file.
`clean`	Remove all intermediary files and binary output files.
`mostlyclean`	Remove all intermediary files but preserve any binary output files.
`<filename>.s`	Create an assembly listing of a given input C/C++ source file.

* * \section SSec_BuildModule_BUILD_MandatoryParams Mandatory Parameters * * * * * * * * * * * * * * * * * * * * * * * * * * *

`TARGET`	Name of the application output file prefix (e.g. `TestApplication`).
`ARCH`	Architecture of the target processor (see \ref Page_DeviceSupport).
`MCU`	Name of the Atmel processor model (e.g. `at90usb1287`).
`SRC`	List of relative or absolute paths to the application C (.c), C++ (.cpp) and Assembly (.S) source files.
`F_USB`	Speed in Hz of the input clock frequency to the target's USB controller.
`LUFA_PATH`	Path to the LUFA library core, either relative or absolute (e.g. `../LUFA-000000/LUFA/`).

* * \section SSec_BuildModule_BUILD_OptionalParams Optional Parameters * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

`BOARD`	LUFA board hardware drivers to use (see \ref Page_DeviceSupport).
`OPTIMIZATION`	Optimization level to use when compiling source files (see GCC manual).
`C_STANDARD`	Version of the C standard to apply when compiling C++ source files (see GCC manual).
`CPP_STANDARD`	Version of the C++ standard to apply when compiling C++ source files (see GCC manual).
`DEBUG_FORMAT`	Format of the debug information to embed in the generated object files (see GCC manual).
`DEBUG_LEVEL`	Level of the debugging information to embed in the generated object files (see GCC manual).
`F_CPU`	Speed of the processor CPU clock, in Hz.
`C_FLAGS`	Flags to pass to the C compiler only, after the automatically generated flags.
`CPP_FLAGS`	Flags to pass to the C++ compiler only, after the automatically generated flags.
`ASM_FLAGS`	Flags to pass to the assembler only, after the automatically generated flags.
`CC_FLAGS`	Common flags to pass to the C/C++ compiler and assembler, after the automatically generated flags.
`LD_FLAGS`	Flags to pass to the linker, after the automatically generated flags.
`LINKER_RELAXATIONS`	Enables or disables linker relaxations when linking the application binary. This can reduce the total size * of the application by replacing full \c CALL instructions with smaller \c RCALL instructions where possible. * \note On some unpatched versions of binutils, this can cause link failures in some circumstances. If you * receive a link error `relocation truncated to fit: R_AVR_13_PCREL`, disable this setting.
`OBJDIR`	Directory to place the generated object and dependency files. If set to "." the same folder as the source file will be used. * \note When this option is enabled, all source filenames must be unique.
`OBJECT_FILES`	List of additional object files that should be linked into the resulting binary.

* * \section SSec_BuildModule_BUILD_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_BUILD_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_CORE The CORE build module * * The core LUFA build system module, providing common build system help and information targets. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_core.mk * \endcode * * \section SSec_BuildModule_CORE_Requirements Requirements * This module has no requirements outside a standard *nix shell like environment; the sh * shell, GNU make and *nix CoreUtils (echo, printf, etc.). * * \section SSec_BuildModule_CORE_Targets Targets * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

`help`	Display build system help and configuration information.
`list_targets`	List all available build targets from the build system.
`list_modules`	List all available build modules from the build system.
`list_mandatory`	List all mandatory parameters required by the included modules.
`list_optional`	List all optional parameters required by the included modules.
`list_provided`	List all variables provided by the included modules.
`list_macros`	List all macros provided by the included modules.

* * \section SSec_BuildModule_CORE_MandatoryParams Mandatory Parameters * * * * * *

None

* * \section SSec_BuildModule_CORE_OptionalParams Optional Parameters * * * * * *

None

* * \section SSec_BuildModule_CORE_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_CORE_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_ATPROGRAM The ATPROGRAM build module * * The ATPROGRAM programming utility LUFA build system module, providing targets to reprogram an * Atmel processor FLASH and EEPROM memories with a project's compiled binary output files. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_atprogram.mk * \endcode * * \section SSec_BuildModule_ATPROGRAM_Requirements Requirements * This module requires the atprogram.exe utility to be available in your system's PATH * variable. The atprogram.exe utility is distributed in Atmel AVR Studio 5.x and Atmel Studio 6.x * inside the application install folder's "\avrdbg" subdirectory. * * \section SSec_BuildModule_ATPROGRAM_Targets Targets * * * * * * * * * * *

`atprogram`	Program the device FLASH memory with the application's executable data.
`atprogram-ee`	Program the device EEPROM memory with the application's EEPROM data.

* * \section SSec_BuildModule_ATPROGRAM_MandatoryParams Mandatory Parameters * * * * * * * * * * *

`MCU`	Name of the Atmel processor model (e.g. `at90usb1287`).
`TARGET`	Name of the application output file prefix (e.g. `TestApplication`).

* * \section SSec_BuildModule_ATPROGRAM_OptionalParams Optional Parameters * * * * * * * * * * * * * * *

`ATPROGRAM_PROGRAMMER`	Name of the Atmel programmer or debugger tool to communicate with (e.g. `jtagice3`).
`ATPROGRAM_INTERFACE`	Name of the programming interface to use when programming the target (e.g. `spi`).
`ATPROGRAM_PORT`	Name of the communication port to use when when programming with a serially connected tool (e.g. `COM2`).

* * \section SSec_BuildModule_ATPROGRAM_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_ATPROGRAM_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_AVRDUDE The AVRDUDE build module * * The AVRDUDE programming utility LUFA build system module, providing targets to reprogram an * Atmel processor FLASH and EEPROM memories with a project's compiled binary output files. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_avrdude.mk * \endcode * * \section SSec_BuildModule_AVRDUDE_Requirements Requirements * This module requires the avrdude utility to be available in your system's PATH * variable. The avrdude utility is distributed in the old WinAVR project releases for * Windows (http://winavr.sourceforge.net) or can be installed on *nix systems via the project's * source code (https://savannah.nongnu.org/projects/avrdude) or through the package manager. * * \section SSec_BuildModule_AVRDUDE_Targets Targets * * * * * * * * * * *

`avrdude`	Program the device FLASH memory with the application's executable data.
`avrdude-ee`	Program the device EEPROM memory with the application's EEPROM data.

* * \section SSec_BuildModule_AVRDUDE_MandatoryParams Mandatory Parameters * * * * * * * * * * *

`MCU`	Name of the Atmel processor model (e.g. `at90usb1287`).
`TARGET`	Name of the application output file prefix (e.g. `TestApplication`).

* * \section SSec_BuildModule_AVRDUDE_OptionalParams Optional Parameters * * * * * * * * * * * * * * *

`AVRDUDE_PROGRAMMER`	Name of the programmer or debugger tool to communicate with (e.g. `jtagicemkii`).
`AVRDUDE_PORT`	Name of the communication port to use when when programming with the connected tool (e.g. `COM2`, `/dev/ttyUSB0` or `usb`).
`AVRDUDE_FLAGS`	Additional flags to pass to avrdude when programming, applied after the automatically generated flags.

* * \section SSec_BuildModule_AVRDUDE_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_AVRDUDE_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_CPPCHECK The CPPCHECK build module * * The CPPCHECK programming utility LUFA build system module, providing targets to statically * analyze C and C++ source code for errors and performance/style issues. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_cppcheck.mk * \endcode * * \section SSec_BuildModule_CPPCHECK_Requirements Requirements * This module requires the cppcheck utility to be available in your system's PATH * variable. The cppcheck utility is distributed through the project's home page * (http://cppcheck.sourceforge.net) for Windows, and can be installed on *nix systems via * the project's source code or through the package manager. * * \section SSec_BuildModule_CPPCHECK_Targets Targets * * * * * * * * * * *

`cppcheck`	Statically analyze the project source code for issues.
`cppcheck-config`	Check the `cppcheck` configuration - scan source code and warn about missing header files and other issues.

* * \section SSec_BuildModule_CPPCHECK_MandatoryParams Mandatory Parameters * * * * * * *

SRC List of source files to statically analyze.

* * \section SSec_BuildModule_CPPCHECK_OptionalParams Optional Parameters * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

`CPPCHECK_INCLUDES`	Path of extra directories to check when attemting to resolve C/C++ header file includes.
`CPPCHECK_EXCLUDES`	Paths or path fragments to exclude when analyzing.
`CPPCHECK_MSG_TEMPLATE`	Output message template to use when printing errors, warnings and information (see `cppcheck` documentation).
`CPPCHECK_ENABLE`	Analysis rule categories to enable (see `cppcheck` documentation).
`CPPCHECK_SUPPRESS`	Specific analysis rules to suppress (see `cppcheck` documentation).
`CPPCHECK_FAIL_ON_WARNING`	Set to Y to fail the analysis job with an error exit code if warnings are found, N to continue without failing.
`CPPCHECK_QUIET`	Set to Y to suppress all output except warnings and errors, N to show verbose output information.
`CPPCHECK_FLAGS`	Extra flags to pass to `cppcheck`, after the automatically generated flags.

* * \section SSec_BuildModule_CPPCHECK_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_CPPCHECK_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_DFU The DFU build module * * The DFU programming utility LUFA build system module, providing targets to reprogram an * Atmel processor FLASH and EEPROM memories with a project's compiled binary output files. * This module requires a DFU class bootloader to be running in the target, compatible with * the DFU bootloader protocol as published by Atmel. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_dfu.mk * \endcode * * \section SSec_BuildModule_DFU_Requirements Requirements * This module requires either the batchisp utility from Atmel's FLIP utility, or the open * source dfu-programmer utility (http://dfu-programmer.sourceforge.net/) to be * available in your system's PATH variable. On *nix systems the dfu-programmer utility * can be installed via the project's source code or through the package manager. * * \section SSec_BuildModule_DFU_Targets Targets * * * * * * * * * * * * * * * * * * *

`dfu`	Program the device FLASH memory with the application's executable data using `dfu-programmer`.
`dfu-ee`	Program the device EEPROM memory with the application's EEPROM data using `dfu-programmer`.
`flip`	Program the device FLASH memory with the application's executable data using `batchisp`.
`flip-ee`	Program the device EEPROM memory with the application's EEPROM data using `batchisp`.

* * \section SSec_BuildModule_DFU_MandatoryParams Mandatory Parameters * * * * * * * * * * *

`MCU`	Name of the Atmel processor model (e.g. `at90usb1287`).
`TARGET`	Name of the application output file prefix (e.g. `TestApplication`).

* * \section SSec_BuildModule_DFU_OptionalParams Optional Parameters * * * * * *

None

* * \section SSec_BuildModule_DFU_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_DFU_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_DOXYGEN The DOXYGEN build module * * The DOXYGEN code documentation utility LUFA build system module, providing targets to generate * project HTML and other format documentation from a set of source files that include special * Doxygen comments. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_doxygen.mk * \endcode * * \section SSec_BuildModule_DOXYGEN_Requirements Requirements * This module requires the doxygen utility from the Doxygen website * (http://www.doxygen.org/) to be available in your system's PATH variable. On *nix * systems the doxygen utility can be installed via the project's source code or through * the package manager. * * \section SSec_BuildModule_DOXYGEN_Targets Targets * * * * * * * * * * * * * * *

`doxygen`	Generate project documentation.
`doxygen_create`	Create a new Doxygen configuration file using the latest template.
`doxygen_upgrade`	Upgrade an existing Doxygen configuration file to the latest template

* * \section SSec_BuildModule_DOXYGEN_MandatoryParams Mandatory Parameters * * * * * * *

LUFA_PATH Path to the LUFA library core, either relative or absolute (e.g. ../LUFA-000000/LUFA/).

* * \section SSec_BuildModule_DOXYGEN_OptionalParams Optional Parameters * * * * * * * * * * * * * * *

`DOXYGEN_CONF`	Name and path of the base Doxygen configuration file for the project.
`DOXYGEN_FAIL_ON_WARNING`	Set to Y to fail the generation with an error exit code if warnings are found other than unsupported configuration parameters, N to continue without failing.
`DOXYGEN_OVERRIDE_PARAMS`	Extra Doxygen configuration parameters to apply, overriding the corresponding config entry in the project's configuration file (e.g. `QUIET=YES`).

* * \section SSec_BuildModule_DOXYGEN_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_DOXYGEN_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_HID The HID build module * * The HID programming utility LUFA build system module, providing targets to reprogram an * Atmel processor's FLASH memory with a project's compiled binary output file. This module * requires a HID class bootloader to be running in the target, using a protocol compatible * with the PJRC "HalfKay" protocol (http://www.pjrc.com/teensy/halfkay_protocol.html). * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_hid.mk * \endcode * * \section SSec_BuildModule_HID_Requirements Requirements * This module requires either the hid_bootloader_cli utility from the included LUFA HID * class bootloader API subdirectory, or the teensy_loader_cli utility from PJRC * (http://www.pjrc.com/teensy/loader_cli.html) to be available in your system's PATH * variable. * * \section SSec_BuildModule_HID_Targets Targets * * * * * * * * * * * * * * * * * * *

`hid`	Program the device FLASH memory with the application's executable data using `hid_bootloader_cli`.
`hid-ee`	Program the device EEPROM memory with the application's EEPROM data using `hid_bootloader_cli` and * a temporary AVR application programmed into the target's FLASH. * \note This will erase the currently loaded application in the target.
`teensy`	Program the device FLASH memory with the application's executable data using `teensy_loader_cli`.
`teensy-ee`	Program the device EEPROM memory with the application's EEPROM data using `teensy_loader_cli` and * a temporary AVR application programmed into the target's FLASH. * \note This will erase the currently loaded application in the target.

* * \section SSec_BuildModule_HID_MandatoryParams Mandatory Parameters * * * * * * * * * * *

`MCU`	Name of the Atmel processor model (e.g. `at90usb1287`).
`TARGET`	Name of the application output file prefix (e.g. `TestApplication`).

* * \section SSec_BuildModule_HID_OptionalParams Optional Parameters * * * * * *

None

* * \section SSec_BuildModule_HID_ProvidedVariables Module Provided Variables * * * * * *

None

* * \section SSec_BuildModule_HID_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildModule_SOURCES The SOURCES build module * * The SOURCES LUFA build system module, providing variables listing the various LUFA source files * required to be build by a project for a given LUFA module. This module gives a way to reference * LUFA source files symbollically, so that changes to the library structure do not break the library * makefile. * * To use this module in your application makefile, add the following code: * \code * include $(LUFA_PATH)/Build/lufa_sources.mk * \endcode * * \section SSec_BuildModule_SOURCES_Requirements Requirements * None. * * \section SSec_BuildModule_SOURCES_Targets Targets * * * * * *

None

* * \section SSec_BuildModule_SOURCES_MandatoryParams Mandatory Parameters * * * * * * * * * * *

`LUFA_PATH`	Path to the LUFA library core, either relative or absolute (e.g. `../LUFA-000000/LUFA/`).
`ARCH`	Architecture of the target processor (see \ref Page_DeviceSupport).

* * \section SSec_BuildModule_SOURCES_OptionalParams Optional Parameters * * * * * *

None

* * \section SSec_BuildModule_SOURCES_ProvidedVariables Module Provided Variables * * * * * * * * * * * * * * * * * * * * * * * * * * *

`LUFA_SRC_USB`	List of LUFA USB driver source files.
`LUFA_SRC_USBCLASS`	List of LUFA USB Class driver source files.
`LUFA_SRC_TEMPERATURE`	List of LUFA temperature sensor driver source files.
`LUFA_SRC_SERIAL`	List of LUFA Serial U(S)ART driver source files.
`LUFA_SRC_TWI`	List of LUFA TWI driver source files.
`LUFA_SRC_PLATFORM`	List of LUFA architecture specific platform management source files.

* * \section SSec_BuildModule_SOURCES_ProvidedMacros Module Provided Macros * * * * * *

None

*/ /** \page Page_BuildTroubleshooting Troubleshooting Information * * LUFA uses a lot of advanced features of the AVR-GCC compiler, linker, and surrounding binaries. This can sometimes lead to problems compiling applications if one of these * features is buggy in the version of the tools used in a build environment. Missing utilities and incorrectly set makefile configuration options can also result in different * errors being produced when compilation or other operations are attempted. The table below lists a set of commonly encountered errors and their resolutions. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Problem	Resolution
Error "`relocation truncated to fit: R_AVR_13_PCREL against symbol {X}`" shown when compiling.	Try compiling with the setting `LINKER_RELAXATIONS=N` in your LUFA Build System 2.0 makefile, or remove the line `-Wl,--relax` * from other makefiles. Alternatively, make sure you have the latest version of the Atmel Toolchain installed for your system.
Error "`error: ld terminated with signal 11 [Segmentation fault]`" shown when compiling.	Try compiling with the setting `DEBUG_LEVEL=2` in your LUFA Build System 2.0 makefile, or make sure you are using `binutils` version 2.22 or later.
Error "`EMERGENCY ABORT: INFINITE RECURSION DETECTED`" shown when compiling.	Make sure you are using an up to date version of GNU Make when compiling. This error is a safety system added to the mid-level makefiles, to prevent an issue with * GNU make or other variants of Make causing an infinitely recursive build.
Error "`Unsupported architecture "{X}"`" shown when compiling.	Ensure your makefile's `ARCH` setting is set to one of the architecture names (case-sensitive) supported by the version of LUFA you are compiling against.
Error "`Makefile {X} value not set`" shown when compiling.	The specified Makefile value was not configured in your project's makefile or on the command line, and the nominated setting is required by one or more LUFA * build system modules. Define the value in your project makefile and try again.
Error "`Makefile {X} option cannot be blank`" shown when compiling.	The specified Makefile value was configured in your project's makefile or on the command line, but was set to an empty value. For the nominated configuration * option, an empty value is not allowed. Define the nominated setting to a correct non-blank value and try again.
Error "`Makefile {X} option must be Y or N`" shown when compiling.	The specified Makefile value was configured in your project's makefile or on the command line, but was set to a value other than a Y (for "Yes") or "N" (for "No"). * This configuration option is required to be one of the aformentioned boolean values, and other values are invalid. Set this option to either Y or N and try again.
Error "`Unknown input source file formats: {X}`" shown when compiling.	The nominated source files, specified in your project's makefile in the `SRC` configuration option, has an extension that the LUFA build system does not * recognise. The file extensions are case sensitive, and must be one of the supported formats (`.c`, `.cpp` or `*.S`).
Error "`Cannot build with OBJDIR parameter set - one or more object file name is not unique`" shown when compiling.	When a project is built with a non-empty `OBJDIR` object directory name set, all input source files must have unique names, excluding extension and path. * This means that input files that are named identically and differ only by their path or extension are invalid when this mode is used.
Error "`Source file does not exist: {X}`" shown when compiling.	The nominated input source file, specified in the user project's `SRC` parameter, could not be found. Ensure the source file exists and the absolute or * relative path given in the user project makefile is correct and try again.
Error "`Doxygen configuration file {X} does not exist`" shown when upgrading a Doxygen configuration file.	The nominated Doxygen configuration file, specified in the user project's `DOXYGEN_CONF` parameter, could not be found. Ensure the configuration file exists * and the absolute or relative path given in the user project makefile is correct and try again, or run the appropriate makefile target to generate a new configuration * file.
Error "`avr-gcc: error: unrecognized option '{X}'`" shown when compiling.	An unrecognised option was supplied to the compiler, usually in the `C_FLAGS`, `CPP_FLAGS`, `ASM_FLAGS` or `CC_FLAGS` configuration * options. The nominated compiler switch may be invalid, or unsupported by the version of AVR-GCC on the host system. Remove the unrecognised flag if invalid, or * upgrade to the latest AVR-GCC. If the option is a valid linker option, use the prefix "-Wl," to ensure it is passed to the linker correctly.
Error "`avr-gcc: error: unrecognized option '{X}'`" shown when compiling.	An unrecognised option was supplied to the compiler, usually in the `C_FLAGS`, `CPP_FLAGS`, `ASM_FLAGS` or `CC_FLAGS` configuration * options. The nominated compiler switch may be invalid, or unsupported by the version of AVR-GCC on the host system. Remove the unrecognised flag if invalid, or * upgrade to the latest AVR-GCC. If the option is a valid linker option, use the prefix "-Wl," to ensure it is passed to the linker correctly.
Error "`makefile:{X}: {Y}.mk: No such file or directory`" shown when make is invoked.	The path to the nominated makefile module was incorrect. This usually indicates that the makefile `LUFA_PATH` option is not set to a valid relative or * absolute path to the LUFA library core.
Error "`makefile:{X}: {Y}.mk: No such file or directory`" shown when make is invoked.	The path to the nominated makefile module was incorrect. This usually indicates that the makefile `LUFA_PATH` option is not set to a valid relative or * absolute path to the LUFA library core.
Error "`fatal error: LUFAConfig.h: No such file or directory`" shown when compiling.	The `USE_LUFA_CONFIG_HEADER` compile time option was set in the user project makefile, but the user supplied `LUFAConfig.h` header could not be * found. Ensure that the directory that contains this configuration file is correctly passed to the compiler via the -I switch in the makefile `CC_FLAGS` * parameter.
Error "`ld.exe: section .apitable_trampolines loaded at {X} overlaps section .text`" shown when compiling a bootloader.	The bootloader is compiling too large for the given `FLASH_SIZE_KB` and `BOOT_SECTION_SIZE_KB` parameters set in the bootloader makefile. This * usually indicates that these values are incorrect for the specified device the bootloader is targeting. If these values are correct, a newer version of the * compiler may need to be used to ensure that the bootloader is built within the section size constraints of the target device.
Error "`unknown MCU '{X}' specified`" shown when compiling.	The specified micocontroller device model name set in the user application's makefile as the `MCU` parameter is incorrect, or unsupported by the * version of the compiler being used. Make sure the model name is correct, or upgrade to the latest Atmel Toolchain to obtain newer device support.
Error "`error: invalid suffix "x" on integer constant`" shown when compiling a bootloader.	This is usually caused by the `bc.exe` application not being found in the system's `PATH` variable. Make sure you have the `bc.exe` tool * installed correctly (see \ref Sec_Prerequisites).
Error "undefined reference to `{X}'" shown when compiling.	This is usually caused by a missing source file in the user application's `SRC` configuration parameter. If the indicated symbol is one from the LUFA * library, you may be missing a LUFA source makefile module (see \ref Page_BuildModule_SOURCES).

* * For troubleshooting other errors you encounter, please see \ref Sec_ProjectHelp. */