nits

da942337 · rsc · 3ce16470 · da942337
--- a/mp.c
+++ b/mp.c
@@ -72,8 +72,7 @@ mp_search(void)
  if((p = (bda[0x0F]<<8)|bda[0x0E])){
    if((mp = mp_scan((uchar*) p, 1024)))
      return mp;
-  }
+  }else{
-  else{
    p = ((bda[0x14]<<8)|bda[0x13])*1024;
    if((mp = mp_scan((uchar*)p-1024, 1024)))
      return mp;
@@ -94,19 +93,20 @@ mp_detect(void)
  uint length;
  if((mp = mp_search()) == 0 || mp->physaddr == 0)
-    return 1;
+    return -1;
  pcmp = (struct mpctb*) mp->physaddr;
-  if(memcmp(pcmp, "PCMP", 4))
+  if(memcmp(pcmp, "PCMP", 4) != 0)
-    return 2;
+    return -1;
+  if(pcmp->version != 1 && pcmp->version != 4)
+    return -1;
  length = pcmp->length;
  sum = 0;
  for(p = (uchar*)pcmp; length; length--)
    sum += *p++;
+  if(sum != 0)
-  if(sum || (pcmp->version != 1 && pcmp->version != 4))
+    return -1;
-    return 3;
  return 0;
 }
@@ -114,20 +114,17 @@ mp_detect(void)
 void
 mp_init(void)
 {
-  int r;
+  int i, r;
  uchar *p, *e;
  struct mpctb *mpctb;
  struct mppe *proc;
  struct mpbe *bus;
  struct mpioapic *ioapic;
  struct mpie *intr;
-  int i;
-  uchar byte;
  ncpu = 0;
-  if((r = mp_detect()) != 0) {
+  if(mp_detect() < 0)
    return;
-  }
  ismp = 1;
@@ -179,11 +176,10 @@ mp_init(void)
  }
  if(mp->imcrp) {
-    // It appears that Bochs doesn't support IMCR, so code won't run.
+    // Bochs doesn't support IMCR, so this doesn't run on Bochs.
+    // But it would on real hardware.
    outb(0x22, 0x70);   // Select IMCR
-    byte = inb(0x23);   // Current contents
+    outb(0x23, inb(0x23) | 1);  // Mask external interrupts.
-    byte |= 0x01;       // Mask external INTR
-    outb(0x23, byte);   // Disconnect 8259s/NMI
  }
 }