Fix cpu detection code.

2 files changed, 94 insertions, 0 deletions

diff --git a/debian/changelog b/debian/changelog
index 5ba94f5..1d2acc9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -13,6 +13,7 @@ gnumach (1:20040915.dfsg.1-1) unstable; urgency=low
     Thanks to Neal H. Walfield <neal@cs.uml.edu>.
   * Fix possible buffer overrun on linux printk.
     Thanks to Neal H. Walfield <neal@cs.uml.edu>.
+  * Fix cpu detection code.
   * Do not use stamp files for build targets.
 
  -- Guillem Jover <guillem@debian.org>  Tue, 16 Nov 2004 07:58:02 +0100
diff --git a/debian/patches/19_cpu_detect.patch b/debian/patches/19_cpu_detect.patch
new file mode 100644
index 0000000..5eb27d5
--- /dev/null
+++ b/debian/patches/19_cpu_detect.patch
@@ -0,0 +1,93 @@
+#DPATCHLEVEL=0
+
+2004-11-22  Guillem Jover  <guillem@hadrons.org>
+
+	* i386/i386/locore.S (discover_x86_cpu_type): Enable function.
+	Enable ID flag for Cyrix CPU. Use %ebp to save the stack pointer.
+	Restore EFLAGS just after its last usage.
+	* i386/i386at/model_dep.c (c_boot_entry): Enable use of
+	discover_x86_cpu_type. Remove hardcoded cpu_type assignment.
+	* i386/include/mach/i386/eflags.h
+	(EFL_AC, EFL_VI, EFL_VIP, EFL_ID): New bits.
+
+
+diff -Naur i386/i386/locore.S i386/i386/locore.S
+--- i386/i386/locore.S	2001-10-07 21:47:15.000000000 +0200
++++ i386/i386/locore.S	2004-11-21 21:40:21.000000000 +0100
+@@ -1144,13 +1144,16 @@
+ 	jmp	_take_trap		/* treat as a trap */
+ 
+ 
+-#if 0
+ /* Discover what kind of cpu we have; return the family number
+    (3, 4, 5, 6, for 386, 486, 586, 686 respectively).  */
+ ENTRY(discover_x86_cpu_type)
+-	movl	%esp,%edx		/* Save stack pointer */
++	pushl	%ebp			/* Save frame pointer */
++	movl	%esp,%ebp		/* Save stack pointer */
+ 	and	$~0x3,%esp		/* Align stack pointer */
+ 
++	inb	$0xe8,%al		/* Enable ID flag for Cyrix CPU ... */
++	andb	$0x80,%al		/* ... in CCR4 reg bit7 */
++	outb	%al,$0xe8
+ 	pushfl				/* Fetch flags ... */
+ 	popl	%eax			/*  ... into eax */
+ 	movl	%eax,%ecx		/* Save original flags for return */
+@@ -1159,6 +1162,8 @@
+ 	popfl				/*  ... In EFLAGS */
+ 	pushfl				/* Fetch flags back ... */
+ 	popl	%eax			/*  ... into eax */
++	pushl	%ecx			/* From ecx... */
++	popfl				/* ... restore original flags */
+ 
+ 	xorl	%ecx,%eax		/* See if any bits didn't change */
+ 	testl	$EFL_AC,%eax		/* Test AC bit */
+@@ -1178,11 +1183,9 @@
+ 	shrl	$8,%eax			/* Slide family bits down */
+ 	andl	$15,%eax		/* And select them */
+ 
+-9:	pushl	%ecx			/* From ecx... */
+-	popfl				/* ... restore original flags */
+-	movl	%edx,%esp		/* Restore stack pointer */
++9:	movl	%ebp,%esp		/* Restore stack pointer */
++	popl	%ebp			/* Restore frame pointer */
+ 	ret				/* And return */
+-#endif
+ 
+ 
+ /**/
+diff -Naur i386/i386at/model_dep.c i386/i386at/model_dep.c
+--- i386/i386at/model_dep.c	2002-05-23 03:54:57.000000000 +0200
++++ i386/i386at/model_dep.c	2004-11-21 21:41:09.000000000 +0100
+@@ -372,7 +372,6 @@
+ 	machine_slot[0].running = TRUE;
+ 	machine_slot[0].cpu_subtype = CPU_SUBTYPE_AT386;
+ 
+-#if 0
+ 	switch (discover_x86_cpu_type ())
+ 	  {
+ 	  case 3:
+@@ -389,10 +388,6 @@
+ 	    machine_slot[0].cpu_type = CPU_TYPE_PENTIUMPRO;
+ 	    break;
+ 	  }
+-#else
+-	machine_slot[0].cpu_type = CPU_TYPE_I386;
+-#endif
+-
+ 
+ 	/*
+ 	 * Start the system.
+diff -Naur i386/include/mach/i386/eflags.h i386/include/mach/i386/eflags.h
+--- i386/include/mach/i386/eflags.h	2001-04-05 08:39:21.000000000 +0200
++++ i386/include/mach/i386/eflags.h	2004-11-21 21:39:13.000000000 +0100
+@@ -45,5 +45,9 @@
+ #define	EFL_NT		0x00004000		/* nested task */
+ #define	EFL_RF		0x00010000		/* resume without tracing */
+ #define	EFL_VM		0x00020000		/* virtual 8086 mode */
++#define	EFL_AC		0x00040000		/* alignment check */
++#define	EFL_VI		0x00080000		/* virtual interrupt */
++#define	EFL_VIP		0x00100000		/* virtual interrupt pending */
++#define	EFL_ID		0x00200000		/* cpuid available */
+ 
+ #endif	/* _MACH_I386_EFLAGS_H_ */