a0                282 kernel/proc.c    np->trapframe->a0 = 0;
a0                532 kernel/proc.c      p->trapframe->a0 = kexec("/init", (char *[]){"/init", 0});
a0                533 kernel/proc.c      if (p->trapframe->a0 == -1) {
a0                 55 kernel/proc.h    /* 112 */ uint64 a0;
a0                 40 kernel/syscall.c     return p->trapframe->a0;
a0                146 kernel/syscall.c     p->trapframe->a0 = syscalls[num]();
a0                149 kernel/syscall.c     p->trapframe->a0 = -1;