System Calls

The following system calls are supported in the MSDOS version of ssim. All supported system calls are subject to any applicable MSDOS limitation.

1: exit     10: unlink    33: access    64: getpagesize
3: read     12: chdir     37: kill      108: sigvec
4: write    17: sbrk      38: stat      136: mkdir
5: open     19: lseek     47: getgid    137: rmdir
6: close    20: getpid    54: ioctl     139: setcontext
8: creat    24: getuid    62: fstat

The getpid() call always returns 0x2000. Similarly, getuid() always returns 100. The kill() call returns EINVAL if the signal is sent to any process other than 0x2000. The getgid() call always returns 10. Ioctl() calls will almost certainly not have the desired effect. The setcontext() call is used to return from the sigtramp signal handler dispatcher.