process acpi interrupt source override entries in a 2nd pass over the madt (APIC) table (thanks erik)

according to erik, virtualbox puts the source overrides
before the ioapic entries so the addirq() call fails
as no ioapics have been declared yet. use a second pass
over the table after we processed the apic entries.

1 files changed, 17 insertions, 5 deletions

diff --git a/sys/src/9/pc/archacpi.c b/sys/src/9/pc/archacpi.c
index 3a5cc3506..0b6e7ea48 100644
--- a/sys/src/9/pc/archacpi.c
+++ b/sys/src/9/pc/archacpi.c
@@ -461,7 +461,7 @@ acpiinit(void)
 	Tbl *t;
 	Apic *a;
 	void *va;
-	uchar *p, *e;
+	uchar *s, *p, *e;
 	ulong lapicbase;
 	int machno, i, c;
 
@@ -497,16 +497,16 @@ acpiinit(void)
 	return;
 
 Foundapic:
-	p = t->data;
-	e = p + tbldlen(t);
-	lapicbase = get32(p); p += 8;
+	s = t->data;
+	e = s + tbldlen(t);
+	lapicbase = get32(s); s += 8;
 	va = vmap(lapicbase, 1024);
 	print("LAPIC: %.8lux %#p\n", lapicbase, va);
 	if(va == nil)
 		panic("acpiinit: cannot map lapic %.8lux", lapicbase);
 
 	machno = 0;
-	for(; p < e; p += c){
+	for(p = s; p < e; p += c){
 		c = p[1];
 		if(c < 2 || (p+c) > e)
 			break;
@@ -555,6 +555,18 @@ Foundapic:
 			mpioapic[a->apicno] = a;
 			ioapicinit(a, a->apicno);
 			break;
+		}
+	}
+
+	/*
+	 * need 2nd pass as vbox puts interrupt overrides
+	 * *before* the ioapic entries (!)
+	 */
+	for(p = s; p < e; p += c){
+		c = p[1];
+		if(c < 2 || (p+c) > e)
+			break;
+		switch(*p){
 		case 0x02:	/* Interrupt Source Override */
 			addirq(get32(p+4), BusISA, 0, p[3], get16(p+8));
 			break;