Keil C51 by default which startup.a51 is used during compiling?

which startup.c51 default file is used during compiling?

in which folder is it located?

is it the startup.a51 in "\lib" folder?

I checked the one above but appears not to be the same one is used in my project

it has some extra instructions compared to the assembled code

Thank you

Fausto Bartra