revert the change to rofsbuild image format, but add checking codes to prevent address overflow
# A1.var
VARIANT A1
EXTENDS groupA
VIRTUAL
BUILD_INCLUDE append /epoc32/include/A1/build
BUILD_INCLUDE prepend /prepend/include/A1
ROM_INCLUDE prepend /epoc32/include/A1/rom
VARIANT_HRH /epoc32/include/e32std.h