a0                280 kernel/proc.c    np->trapframe->a0 = 0;
a0                524 kernel/proc.c      p->trapframe->a0 = kexec("/init", (char *[]){ "/init", 0 });
a0                525 kernel/proc.c      if (p->trapframe->a0 == -1) {
a0                 58 kernel/proc.h    /* 112 */ uint64 a0;
a0                 39 kernel/syscall.c     return p->trapframe->a0;
a0                141 kernel/syscall.c     p->trapframe->a0 = syscalls[num]();
a0                145 kernel/syscall.c     p->trapframe->a0 = -1;