diff --git a/inc/hf/dlog.h b/inc/hf/dlog.h
index 0e77d9b..18872ae 100644
--- a/inc/hf/dlog.h
+++ b/inc/hf/dlog.h
@@ -19,9 +19,13 @@
 #include <stdarg.h>
 
 #if DEBUG
+void dlog_nosync(const char *fmt, ...);
+void vdlog_nosync(const char *fmt, va_list args);
 void dlog(const char *fmt, ...);
 void vdlog(const char *fmt, va_list args);
 #else
+#define dlog_nosync(...)
+#define vdlog_nosync(fmt, args)
 #define dlog(...)
 #define vdlog(fmt, args)
 #endif
diff --git a/src/arch/aarch64/mm.c b/src/arch/aarch64/mm.c
index 2867fd9..e6c723b 100644
--- a/src/arch/aarch64/mm.c
+++ b/src/arch/aarch64/mm.c
@@ -183,19 +183,21 @@
 
 	/* Check that 4KB granules are supported. */
 	if ((features >> 28) & 0xf) {
-		dlog("4KB granules are not supported\n");
+		dlog_nosync("4KB granules are not supported\n");
 		return false;
 	}
 
 	/* Check the physical address range. */
 	if (!pa_bits) {
-		dlog("Unsupported value of id_aa64mmfr0_el1.PARange: %x\n",
-		     features & 0xf);
+		dlog_nosync(
+			"Unsupported value of id_aa64mmfr0_el1.PARange: %x\n",
+			features & 0xf);
 		return false;
 	}
 
 	if (first) {
-		dlog("Supported bits in physical address: %d\n", pa_bits);
+		dlog_nosync("Supported bits in physical address: %d\n",
+			    pa_bits);
 	}
 
 	/*
@@ -211,7 +213,8 @@
 	}
 
 	if (first) {
-		dlog("Number of page table levels: %d\n", mm_max_s2_level + 1);
+		dlog_nosync("Number of page table levels: %d\n",
+			    mm_max_s2_level + 1);
 	}
 
 	v = (1u << 31) |	       /* RES1. */
diff --git a/src/dlog.c b/src/dlog.c
index e9643c5..9737805 100644
--- a/src/dlog.c
+++ b/src/dlog.c
@@ -176,18 +176,17 @@
 }
 
 /**
- * Same as "dlog", except that arguments are passed as a va_list.
+ * Same as "dlog_nosync", except that arguments are passed as a va_list. This
+ * must only be used before the MMU has been initialized so that the atomic
+ * operations needed for locking are operational.
  */
-void vdlog(const char *fmt, va_list args)
+void vdlog_nosync(const char *fmt, va_list args)
 {
-	static struct spinlock sl = SPINLOCK_INIT;
 	const char *p;
 	size_t w;
 	int flags;
 	char buf[2];
 
-	sl_lock(&sl);
-
 	for (p = fmt; *p; p++) {
 		switch (*p) {
 		default:
@@ -281,7 +280,31 @@
 			break;
 		}
 	}
+}
 
+/**
+ * Prints the given format string to the debug log without locking. This must
+ * only be used before the MMU has been initialized so that the atomic
+ * operations needed for locking are operational.
+ */
+void dlog_nosync(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vdlog_nosync(fmt, args);
+	va_end(args);
+}
+
+/**
+ * Same as "dlog", except that arguments are passed as a va_list.
+ */
+void vdlog(const char *fmt, va_list args)
+{
+	static struct spinlock sl = SPINLOCK_INIT;
+
+	sl_lock(&sl);
+	vdlog_nosync(fmt, args);
 	sl_unlock(&sl);
 }
 
diff --git a/src/main.c b/src/main.c
index 734caf5..7c02e6d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -44,13 +44,13 @@
 
 	/* TODO: Block all CPUs. */
 
-	dlog("Panic: ");
+	dlog_nosync("Panic: ");
 
 	va_start(args, fmt);
-	vdlog(fmt, args);
+	vdlog_nosync(fmt, args);
 	va_end(args);
 
-	dlog("\n");
+	dlog_nosync("\n");
 
 	for (;;) {
 	}
@@ -68,7 +68,7 @@
 	void *initrd;
 	size_t i;
 
-	dlog("Initialising hafnium\n");
+	dlog_nosync("Initialising hafnium\n");
 
 	cpu_module_init();
 	halloc_init((size_t)ptable_buf, sizeof(ptable_buf));
diff --git a/src/mm.c b/src/mm.c
index 3e17f47..9aa21be 100644
--- a/src/mm.c
+++ b/src/mm.c
@@ -711,15 +711,15 @@
  */
 bool mm_init(void)
 {
-	dlog("text: 0x%x - 0x%x\n", pa_addr(layout_text_begin()),
-	     pa_addr(layout_text_end()));
-	dlog("rodata: 0x%x - 0x%x\n", pa_addr(layout_rodata_begin()),
-	     pa_addr(layout_rodata_end()));
-	dlog("data: 0x%x - 0x%x\n", pa_addr(layout_data_begin()),
-	     pa_addr(layout_data_end()));
+	dlog_nosync("text: 0x%x - 0x%x\n", pa_addr(layout_text_begin()),
+		    pa_addr(layout_text_end()));
+	dlog_nosync("rodata: 0x%x - 0x%x\n", pa_addr(layout_rodata_begin()),
+		    pa_addr(layout_rodata_end()));
+	dlog_nosync("data: 0x%x - 0x%x\n", pa_addr(layout_data_begin()),
+		    pa_addr(layout_data_end()));
 
 	if (!mm_ptable_init(&ptable, MM_MODE_NOSYNC | MM_MODE_STAGE1)) {
-		dlog("Unable to allocate memory for page table.\n");
+		dlog_nosync("Unable to allocate memory for page table.\n");
 		return false;
 	}