Index: sys/arm64/arm64/locore.S
===================================================================
--- sys/arm64/arm64/locore.S
+++ sys/arm64/arm64/locore.S
@@ -361,18 +361,40 @@
 	mov	x5, x30
 
 	/* Clean the page table */
-	adrp	x6, pagetable
-	add	x6, x6, :lo12:pagetable
-	mov	x26, x6
+	adrp	x26, pagetable
+	add	x26, x26, :lo12:pagetable
 	adrp	x27, pagetable_end
 	add	x27, x27, :lo12:pagetable_end
+
+	mrs	x7, ctr_el0
+	/* Extract the DminLine field */
+	ubfm	x7, x7, #16, #19
+	/* DminLine is log2(dcacheline size) in 4-byte words */
+	mov	x8, #4
+	lsl	x7, x8, x7
+
+	/*
+	 * Invalidate cachelines holding the page tables. We are about to
+	 * write to them with the cache disabled. Any data in the cache
+	 * needs to be invalidated so it doesn't later overwrite them.
+	 */
+	mov	x6, x26
 1:
+	dc	civac, x6
+	add	x6, x6, x7
+	cmp	x6, x27
+	b.lo	1b
+	dsb	sy
+
+	/* Zero the page tables */
+	mov	x6, x26
+2:
 	stp	xzr, xzr, [x6], #16
 	stp	xzr, xzr, [x6], #16
 	stp	xzr, xzr, [x6], #16
 	stp	xzr, xzr, [x6], #16
 	cmp	x6, x27
-	b.lo	1b
+	b.lo	2b
 
 	/*
 	 * Build the TTBR1 maps.