From 7871ef692a29402ba8e3f03b3ee8940233e67e4e Mon Sep 17 00:00:00 2001
From: stefan <stefan@315a16e6-25f9-4109-90ae-ca3045a26c18>
Date: Fri, 26 Nov 2010 18:15:09 +0000
Subject: [PATCH] - add workaround to run the apic code correctly on qemu 12.5

git-svn-id: http://svn.lfbs.rwth-aachen.de/svn/scc/trunk/MetalSVM@290 315a16e6-25f9-4109-90ae-ca3045a26c18
---
 arch/x86/kernel/apic.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index 60f506f7..7649770d 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -55,11 +55,13 @@ static inline void apic_write(uint32_t addr, uint32_t value)
 
 #ifndef CONFIG_MULTIBOOT
 static unsigned int* search_apic(unsigned int base, unsigned int limit) {
-	unsigned int *ptr;
+	uint32_t* ptr;
 
-	for (ptr = (unsigned int *) base; (unsigned int) ptr < limit; ptr++) {
-		if (*ptr == MP_FLT_SIGNATURE)
-			return ptr;
+	for (ptr = (uint32_t*) base; (uint32_t) ptr < limit; ptr++) {
+		if (*ptr == MP_FLT_SIGNATURE) {
+			if (!(((apic_mp_t*)ptr)->version > 4) && ((apic_mp_t*)ptr)->features[0])
+				return ptr;
+		}
         }
 
 	return NULL;
@@ -163,9 +165,10 @@ static int apic_probe(void)
 				addr = mmap->addr;
 
 				for(i=0; i<mmap->len; i++, addr++) {
-					if (strncmp((void*)addr, "_MP_", 4) == 0) {
+					if (*((uint32_t*) addr) == MP_FLT_SIGNATURE) {
 						apic_mp = (apic_mp_t*) addr;
-						goto found_mp;
+						if (!(apic_mp->version > 4) && apic_mp->features[0])
+							goto found_mp;
 					}
 				}
 				
@@ -183,8 +186,8 @@ found_mp:
 	if (!apic_mp) 
 		goto no_mp;
 
-	kprintf("System uses Multiprocessing Specification 1.%d\n", apic_mp->version);	
-	kprintf("MP features 1: %d\n", apic_mp->features[0]);
+	kprintf("System uses Multiprocessing Specification 1.%u\n", apic_mp->version);	
+	kprintf("MP features 1: %u\n", apic_mp->features[0]);
 
 	if (apic_mp->features[0]) {
 		kputs("Currently, MetalSVM supports only multiprocessing via the MP config tables!\n");
@@ -208,7 +211,7 @@ found_mp:
 			addr += 20;
 		} else addr += 8;
 	}
-	kprintf("Found %d cores\n", count);
+	kprintf("Found %u cores\n", count);
 
 	if (count > MAX_CORES) {
 		kputs("Found too many cores! Increase the macro MAX_CORES!\n");