Series 300 Only

NAME

crt0.o, mcrt0.o, frt0.o, mfrt0.o − execution startup routines

DESCRIPTION

The C and Pascal compilers link in either crt0.o or mcrt0.o to provide startup capabilities and environment for program execution.  The only difference between the two is that the latter provides additional functionality for profiling.  Similarly, the Fortran compiler will link in either frt0.o or mfrt0.o.

The following are defined in these routines:

start Execution start address. 

­_argc_value A variable of type int containing the number of arguments. 

­_argv_value An array of character pointers to the arguments themselves. 

­_environ An array of character pointers to the environment in which the program will run. This array is terminated by a null pointer. 

­float_soft A variable of type short which is zero if the 98635 floating point card is present; non-zero if it is not present. 

­float_loc A constant defining the location in memory of the 98635 floating point card. 

­flag_68881 A variable of type short which is non-zero if the 68881 floating point coprocessor is present; zero if it is not present. 

In addition, mcrt0.o and mfrt0.o define _exit and _cntbase which are only useful to profiling routines. 

ORIGIN

AT&T System III

SEE ALSO

cc(1), fc(1), prof(1), pc(1), profil(2), exec(2), monitor(3C). 

Hewlett-Packard Company  —  May 11, 2021