General

GCC

-march=armv6-m
-mtune=cortex-m0plus
-mcpu=cortex-m0plus
-mlong-calls
-mthumb
-mno-unaligned-access
To find unused functions: -ffunction-sections -fdata-sections -Wl,--gc-sections,--print-gc-sections

Passing linker options through gcc with -Wl,
gcc -Wl,-Tlinkerscript.ld

Passing assembler options through gcc with -Wa,
gcc -Wa,-ag

Argument	Description	Example
`-c`	Stop after assembly	`# gcc main.c -c -o main.o`
`-S`	Stop after compile before assembly	`# gcc main.c -S -o main.s`
`-E`	Stop after preprocessor	`# gcc main.c -E -o main.pp`
`-M`	Generate file suitable for Make	`# gcc main.c -M -o main.mk`