There may exist two kinds of IBM BlueLightning CPU. One is that 5/2

test does not change undefined flag like Cyrix CPUs.  Another is that
5/2 test changes undefined flag like Intel CPUs.  Latter one could not
be detected and was recognized 486DX CPU.  To solve this,
finishidentcpu() calls identblue() when cpu_vendor is null string
(that is, CPUID instruction is not supported) and cpu == CPU_486.
Tests have been done on IBM BlueLightning CPUs, i486SX and i486DX.

1 files changed, 15 insertions, 1 deletions

diff --git a/sys/amd64/amd64/identcpu.c b/sys/amd64/amd64/identcpu.c
index 9ed2869..ba53f4e 100644
--- a/sys/amd64/amd64/identcpu.c
+++ b/sys/amd64/amd64/identcpu.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	from: Id: machdep.c,v 1.193 1996/06/18 01:22:04 bde Exp
- *	$Id: identcpu.c,v 1.70 1999/07/06 12:42:26 peter Exp $
+ *	$Id: identcpu.c,v 1.71 1999/07/06 13:23:56 peter Exp $
  */
 
 #include "opt_cpu.h"
@@ -856,6 +856,20 @@ finishidentcpu(void)
 				break;
 			}
 		}
+	} else if (cpu == CPU_486 && *cpu_vendor == '\0') {
+		/*
+		 * There are BlueLightning CPUs that do not change
+		 * undefined flags by dividing 5 by 2.  In this case,
+		 * the CPU identification routine in locore.s leaves
+		 * cpu_vendor null string and puts CPU_486 into the
+		 * cpu.
+		 */
+		isblue = identblue();
+		if (isblue == IDENTBLUE_IBMCPU) {
+			strcpy(cpu_vendor, "IBM");
+			cpu = CPU_BLUE;
+			return;
+		}
 	}
 }