diff --git a/Makefile.target b/Makefile.target
index bdc365908c126a76bce5cd7db23e9bc351f2e60c..aa9a01306926555636b86bc44e23a4ad16e04f53 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -357,7 +357,7 @@ VL_OBJS+= grackle_pci.o prep_pci.o unin_pci.o
 DEFINES += -DHAS_AUDIO
 endif
 ifeq ($(TARGET_ARCH), mips)
-VL_OBJS+= mips_r4k.o dma.o vga.o serial.o i8254.o i8259.o ide.o
+VL_OBJS+= mips_r4k.o mips_timer.o dma.o vga.o serial.o i8254.o i8259.o ide.o
 #VL_OBJS+= #pckbd.o fdc.o m48t59.o
 endif
 ifeq ($(TARGET_BASE_ARCH), sparc)
diff --git a/hw/mips_r4k.c b/hw/mips_r4k.c
index 60eb191bdfa16a354872d9037e069e71d35cb4f3..0ddd9162787a257f6f7901de278636f7dfa97b67 100644
--- a/hw/mips_r4k.c
+++ b/hw/mips_r4k.c
@@ -1,3 +1,12 @@
+/*
+ * QEMU/MIPS pseudo-board
+ *
+ * emulates a simple machine with ISA-like bus.
+ * ISA IO space mapped to the 0x14000000 (PHYS) and
+ * ISA memory at the 0x10000000 (PHYS, 16Mb in size).
+ * All peripherial devices are attached to this "bus" with
+ * the standard PC ISA addresses.
+*/
 #include "vl.h"
 
 #define BIOS_FILENAME "mips_bios.bin"
@@ -13,8 +22,10 @@ static const int ide_irq[2] = { 14, 15 };
 
 extern FILE *logfile;
 
-static PITState *pit;
+static PITState *pit; /* PIT i8254 */
 
+/*i8254 PIT is attached to the IRQ0 at PIC i8259 */
+/*The PIC is attached to the MIPS CPU INT0 pin */
 static void pic_irq_request(void *opaque, int level)
 {
     CPUState *env = first_cpu;
@@ -27,89 +38,6 @@ static void pic_irq_request(void *opaque, int level)
     }
 }
 
-void cpu_mips_irqctrl_init (void)
-{
-}
-
-/* XXX: do not use a global */
-uint32_t cpu_mips_get_random (CPUState *env)
-{
-    static uint32_t seed = 0;
-    uint32_t idx;
-    seed = seed * 314159 + 1;
-    idx = (seed >> 16) % (MIPS_TLB_NB - env->CP0_Wired) + env->CP0_Wired;
-    return idx;
-}
-
-/* MIPS R4K timer */
-uint32_t cpu_mips_get_count (CPUState *env)
-{
-    return env->CP0_Count +
-        (uint32_t)muldiv64(qemu_get_clock(vm_clock),
-                           100 * 1000 * 1000, ticks_per_sec);
-}
-
-static void cpu_mips_update_count (CPUState *env, uint32_t count,
-                                   uint32_t compare)
-{
-    uint64_t now, next;
-    uint32_t tmp;
-    
-    tmp = count;
-    if (count == compare)
-        tmp++;
-    now = qemu_get_clock(vm_clock);
-    next = now + muldiv64(compare - tmp, ticks_per_sec, 100 * 1000 * 1000);
-    if (next == now)
-	next++;
-#if 0
-    if (logfile) {
-        fprintf(logfile, "%s: 0x%08" PRIx64 " %08x %08x => 0x%08" PRIx64 "\n",
-                __func__, now, count, compare, next - now);
-    }
-#endif
-    /* Store new count and compare registers */
-    env->CP0_Compare = compare;
-    env->CP0_Count =
-        count - (uint32_t)muldiv64(now, 100 * 1000 * 1000, ticks_per_sec);
-    /* Adjust timer */
-    qemu_mod_timer(env->timer, next);
-}
-
-void cpu_mips_store_count (CPUState *env, uint32_t value)
-{
-    cpu_mips_update_count(env, value, env->CP0_Compare);
-}
-
-void cpu_mips_store_compare (CPUState *env, uint32_t value)
-{
-    cpu_mips_update_count(env, cpu_mips_get_count(env), value);
-    env->CP0_Cause &= ~0x00008000;
-    cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
-}
-
-static void mips_timer_cb (void *opaque)
-{
-    CPUState *env;
-
-    env = opaque;
-#if 0
-    if (logfile) {
-        fprintf(logfile, "%s\n", __func__);
-    }
-#endif
-    cpu_mips_update_count(env, cpu_mips_get_count(env), env->CP0_Compare);
-    env->CP0_Cause |= 0x00008000;
-    cpu_interrupt(env, CPU_INTERRUPT_HARD);
-}
-
-void cpu_mips_clock_init (CPUState *env)
-{
-    env->timer = qemu_new_timer(vm_clock, &mips_timer_cb, env);
-    env->CP0_Compare = 0;
-    cpu_mips_update_count(env, 1, 0);
-}
-
 static void mips_qemu_writel (void *opaque, target_phys_addr_t addr,
 			      uint32_t val)
 {
@@ -247,7 +175,7 @@ void mips_r4k_init (int ram_size, int vga_ram_size, int boot_device,
 	env->initrd_filename = initrd_filename;
     }
 
-    /* Init internal devices */
+    /* Init CPU internal devices */
     cpu_mips_clock_init(env);
     cpu_mips_irqctrl_init();
 
diff --git a/hw/mips_timer.c b/hw/mips_timer.c
new file mode 100644
index 0000000000000000000000000000000000000000..251324d7b8fab7ecd93fa54292d2470bc2912e5e
--- /dev/null
+++ b/hw/mips_timer.c
@@ -0,0 +1,85 @@
+#include "vl.h"
+
+void cpu_mips_irqctrl_init (void)
+{
+}
+
+/* XXX: do not use a global */
+uint32_t cpu_mips_get_random (CPUState *env)
+{
+    static uint32_t seed = 0;
+    uint32_t idx;
+    seed = seed * 314159 + 1;
+    idx = (seed >> 16) % (MIPS_TLB_NB - env->CP0_Wired) + env->CP0_Wired;
+    return idx;
+}
+
+/* MIPS R4K timer */
+uint32_t cpu_mips_get_count (CPUState *env)
+{
+    return env->CP0_Count +
+        (uint32_t)muldiv64(qemu_get_clock(vm_clock),
+                           100 * 1000 * 1000, ticks_per_sec);
+}
+
+static void cpu_mips_update_count (CPUState *env, uint32_t count,
+                                   uint32_t compare)
+{
+    uint64_t now, next;
+    uint32_t tmp;
+
+    tmp = count;
+    if (count == compare)
+        tmp++;
+    now = qemu_get_clock(vm_clock);
+    next = now + muldiv64(compare - tmp, ticks_per_sec, 100 * 1000 * 1000);
+    if (next == now)
+	next++;
+#if 0
+    if (logfile) {
+        fprintf(logfile, "%s: 0x%08" PRIx64 " %08x %08x => 0x%08" PRIx64 "\n",
+                __func__, now, count, compare, next - now);
+    }
+#endif
+    /* Store new count and compare registers */
+    env->CP0_Compare = compare;
+    env->CP0_Count =
+        count - (uint32_t)muldiv64(now, 100 * 1000 * 1000, ticks_per_sec);
+    /* Adjust timer */
+    qemu_mod_timer(env->timer, next);
+}
+
+void cpu_mips_store_count (CPUState *env, uint32_t value)
+{
+    cpu_mips_update_count(env, value, env->CP0_Compare);
+}
+
+void cpu_mips_store_compare (CPUState *env, uint32_t value)
+{
+    cpu_mips_update_count(env, cpu_mips_get_count(env), value);
+    env->CP0_Cause &= ~0x00008000;
+    cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
+}
+
+static void mips_timer_cb (void *opaque)
+{
+    CPUState *env;
+
+    env = opaque;
+#if 0
+    if (logfile) {
+        fprintf(logfile, "%s\n", __func__);
+    }
+#endif
+    cpu_mips_update_count(env, cpu_mips_get_count(env), env->CP0_Compare);
+    env->CP0_Cause |= 0x00008000;
+    cpu_interrupt(env, CPU_INTERRUPT_HARD);
+}
+
+void cpu_mips_clock_init (CPUState *env)
+{
+    env->timer = qemu_new_timer(vm_clock, &mips_timer_cb, env);
+    env->CP0_Compare = 0;
+    cpu_mips_update_count(env, 1, 0);
+}
+
diff --git a/vl.h b/vl.h
index eedef51bd524889ccc3ffdd4dc21142c8da1da8d..89b24cf918d24853a6ce390fdea006a9c41bd1d2 100644
--- a/vl.h
+++ b/vl.h
@@ -1024,6 +1024,10 @@ extern QEMUMachine heathrow_machine;
 /* mips_r4k.c */
 extern QEMUMachine mips_machine;
 
+/* mips_timer.c */
+extern void cpu_mips_clock_init(CPUState *);
+extern void cpu_mips_irqctrl_init (void);
+
 /* shix.c */
 extern QEMUMachine shix_machine;