mp: do not panic on surprising hw

af6a6a47 · Russ Cox · 1a81e38b · af6a6a47
--- a/mp.c
+++ b/mp.c
@@ -113,9 +113,10 @@ mpinit(void)
    switch(*p){
    case MPPROC:
      proc = (struct mpproc*)p;
+      cprintf("mpproc %d\n", proc->apicid);
      if(ncpu != proc->apicid){
-        cprintf("mpinit: ncpu=%d apicpid=%d\n", ncpu, proc->apicid);
+        cprintf("mpinit: ncpu=%d apicid=%d\n", ncpu, proc->apicid);
-        panic("mpinit");
+        ismp = 0;
      }
      if(proc->flags & MPBOOT)
        bcpu = &cpus[ncpu];
@@ -135,9 +136,17 @@ mpinit(void)
      continue;
    default:
      cprintf("mpinit: unknown config type %x\n", *p);
-      panic("mpinit");
+      ismp = 0;
    }
  }
+  if(!ismp){
+    // Didn't like what we found; fall back to no MP.
+    ncpu = 1;
+    lapic = 0;
+    ioapicid = 0;
+    return;
+  }
  if(mp->imcrp){
    // Bochs doesn't support IMCR, so this doesn't run on Bochs.
    // But it would on real hardware.