From 8825b399c4ea89184fbce73a011fb7f5c43060ae Mon Sep 17 00:00:00 2001
From: Ali Mashtizadeh <mashti@cs.stanford.edu>
Date: Mon, 16 Feb 2015 13:59:24 -0800
Subject: [PATCH] Improve MP debugging

---
 sys/amd64/mp.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/sys/amd64/mp.c b/sys/amd64/mp.c
index 959cca7..134777c 100644
--- a/sys/amd64/mp.c
+++ b/sys/amd64/mp.c
@@ -14,14 +14,23 @@
 #include <machine/pmap.h>
 #include <machine/lapic.h>
 
-#define MP_WAITTIME	250000000ULL
-
 extern uint8_t mpstart_begin[];
 extern uint8_t mpstart_end[];
 
 extern AS systemAS;
 
-volatile bool booted;
+#define MP_WAITTIME	250000000ULL
+
+#define CPUSTATE_NOT_PRESENT	0
+#define CPUSTATE_BOOTED		1
+
+typedef struct CPUState {
+    int			state;
+    UnixEpochNS		heartbeat;
+} CPUState;
+
+volatile static bool booted;
+volatile static CPUState cpus[MAX_CPUS];
 
 static int
 MPBootAP(int procNo)
@@ -75,18 +84,28 @@ MP_Init()
 	if (MPBootAP(i) < 0)
 	    break;
     }
+
+    cpus[CPU()].state = CPUSTATE_BOOTED;
 }
 
 void
 MP_InitAP()
 {
     kprintf("AP %d booted!\n", CPU());
+    cpus[CPU()].state = CPUSTATE_BOOTED;
     booted = 1;
 }
 
 static void
 Debug_CPUS(int argc, const char *argv[])
 {
+    int c;
+
+    for (c = 0; c < MAX_CPUS; c++) {
+	if (cpus[c].state != CPUSTATE_NOT_PRESENT) {
+	    kprintf("CPU %d: BOOTED\n", c);
+	}
+    }
 }
 
 REGISTER_DBGCMD(cpus, "Show MP information", Debug_CPUS);