Process Startup - Static Program

Linker adds csu objects to program:
crt0.o, crtbegin.o, crtend.o
Kernel sets up stack with environment vars and command line arguments
Kernel transfers control to entry point __start in crt0.o
crt0.o is created from per arch source in /usr/src/lib/csu and translates the startup into c calling conventions using assembly
csu calls main() function

$ cc -v -static hello.o -o hello
Reading specs from /usr/lib/gcc-lib/i386-unknown-openbsd4.4/3.3.5/specs
Configured with:
Thread model: single
gcc version 3.3.5 (propolice)
 /usr/lib/gcc-lib/i386-unknown-openbsd4.4/3.3.5/collect2
   -e __start -Bstatic -dynamic-linker /usr/libexec/ld.so
   -o hello /usr/lib/crt0.o /usr/lib/crtbegin.o
   -L/usr/lib/gcc-lib/i386-unknown-openbsd4.4/3.3.5
   hello.o -lgcc -lc -lgcc /usr/lib/crtend.o