kernel: riscv: print processes from tid #0

Start numbering threads from index 0. This matches up with what the rest
of the system uses.

Signed-off-by: Sean Cross <sean@xobs.io>

kernel/src/arch/riscv/irq.rs

@@ -132,7 +132,10 @@ pub extern "C" fn trap_handler(
         && sstatus::read().spp() == sstatus::SPP::Supervisor
         && sc.bits() == 0xf
     {
-        panic!("Ran out of kernel stack");
+        let pid = current_pid();
+        let ex = RiscvException::from_regs(sc.bits(), sepc::read(), stval::read());
+        print!("KERNEL({}): RISC-V fault: {} - ", pid, ex);
+        panic!("Maybe ran out of kernel stack?");
     }
 
     let pid = current_pid();

kernel/src/arch/riscv/process.rs

@@ -435,7 +435,7 @@ impl Process {
     pub fn print_all_threads(&self) {
         let process = unsafe { &mut *PROCESS };
         for (tid_idx, &thread) in process.threads.iter().enumerate() {
-            let tid = tid_idx + 1;
+            let tid = tid_idx;
             if thread.registers[1] != 0 {
                 Self::print_thread(tid, &thread);
             }