ARM Compiler and Toolchain Options: GUI

To get help about ARM GCC Toolchain, you can do the following:

For general information about GCC, visit the official GNU GCC web site
Alternatively, you can write arm-none-eabi-gcc --help and see the explanation of some of the parameters in the command output

This section illustrates the GUI options that are available for the ARM GNU Toolchain in Atmel Studio.

Figure 1. ARM GNU Toolchain Properties

Table 1. ARM GNU Common Options
Option	Description
Thumb(-mthumb)/ARM(-marm)	Switch between ARM and Thumb processor mode

Table 2. ARM GNU C Compiler Options
Option	Description
Preprocessor options
-nostdinc	Do not search system include directories
-E	Preprocess only; Do not compile, Assemble, or link
Symbols options
There one can define (-D) or undefine (-U) a number of in-source symbols. New symbol declarations can be added, modified, or reordered, using the interface buttons below: Add a new symbol. This and all following icons are reused with the same meaning in other parts of Atmel Studio interface. Remove a symbol. Edit symbol. Move the symbol up in the parsing order. Move the symbol down in the parsing order.
Include directories
Default Include Path	Enabling this option will add the include path that is specific to the selected SAM device
Contains all the included header and definition directories, can be modified, using the same interface as symbols
Optimization options
Optimization level (drop-down menu): -O0, -O1, -O2, -O3, -Os	No optimization, optimize for speed (level 1 - 3), optimize for size
Other optimization flags (manual input form)	Here you should write optimization flags specific to the platform and your requirements
-ffunction-sections	Place each function into its own section
-funsafe-math-optimizations	Enable unsafe match optimizations
-ffast-math	Enable fast math
-fpic	Generate position independent code
Debug options
Debug level (drop-down menu): none, -g1, -g2, -g3	Specifies the level of tracing and debugging code and headers left or inserted in the source code
Other debug options (form field)	Architecture-specific debug options
-pg	Generate gprof information
-p	Generate prof information
Warning messages output options
-Wall	All warnings
-Werror	Treat all warnings as errors
-fsyntax-only	Check syntax only
-pedantic	Check conformity to GNU, raise warnings on non-standard programming practice
-pedantic-errors	Same as above, plus escalate warnings to errors
-w	Inhibits all warnings
Miscellaneous options
Other flags (form field)	Input other project-specific flags
-v	Verbose (Display the programs invoked by the compiler)
-ansi	Support ANSI programs
-save-temps	Do not delete intermediate files
Option	Description

Table 3. ARM GCC Linker Options
Option	Description
-Wl -nostartfiles	Do not use standard files
-Wl -nodefault	Do not use default libraries
-Wl -nostdlib	No start-up or default libraries
-Wl -s	Omit all symbol information
-Wl -static	Link statically
-Map	Generates Map file
Libraries options
Libraries -Wl, -l (form field)	You can add, prioritize, or edit library names here, using those buttons: , , , ,
Library search path -Wl, -L (form field)	You can add, prioritize, or edit path where the linker will search for dynamically linked libraries. Same interface as above.
Optimization options
-Wl, -gc-sections	Garbage collect unused sections
-funsafe-math-optimizations	Enable unsafe math optimizations
-ffast-math	Enable fast math
-fpic	Generate position independent code
Miscellaneous options
Other linker flags (form field)	Input other project-specific flags
Option	Description

Linker Scripts

In 'linker->miscellaneous->linker flags' ($LinkerScript_FLASH) is added by default. It will be replaced with the appropriate (device_name)_flash.ld file during Build. Similarly ($LinkerScript_SRAM) will be replaced with the appropriate (device_name)_sram.ld file.
You can always override the default flash linker scripts by replacing ($LinkerScript_FLASH) or ($LinkerScript_SRAM) with your custom linker script option -T'custom_linker_script.ld'.

Note: These device-specific linker scripts will be available in the 'ProjectFolder/Linkerscripts' directory. In case of changing the device after project creation, Atmel Studio will automatically add the correct linker scripts for the selected device.

ARM Assembler Options

Table 4. Arm Assembler Options
Option	Description
Optimization options
Assembler flags (form field)	Miscellaneous assembler flags
Include path (form field)	You can add, prioritize, or edit path to the architecture and platform specific included files here
-v	Announce version in the assembler output
-W	Suppress Warnings
Debugging options
Debugging level (drop-down menu) None, (-g).	Enable debugging symbols and debugging source insertion
Option	Description

ARM Preprocessing Assembler Options

Table 5. ARM Preprocessing Assembler Options
Option	Description
Optimization options
Assembler flags (form field)	Miscellaneous assembler flags
Include path (form field)	You can add, prioritize, or edit path to the architecture and platform specific included files here
-v	Announce version in the assembler output
-W	Suppress Warnings
Debugging options
Debugging level (drop-down menu) None, -Wa -g.	Enables debugging symbols and debugging source insertion
Option	Description