Just tried several optimization levels.
None of the default worked but:
All optimization levels except -Os (-O, -O1, -O2 and even -O3) worked and without display errors if I remove -fno-common drom the compile options.
set CFLAGS=-Wall -O3 -Werror -mcpu=cortex-m3 -mthumb -msoft-float -MD -I !STM_INC! -I !SRC_INC! -I !SRC_SRC!Trouble is: The app only initializes correctly about 1/3 of the times. The other 2/3, the version screen appears and then only a black screen.
Not a showstoper, but clearly some initialization is failing.