diff --git a/Makefile.target b/Makefile.target
index fc3dfaa..1e9815c 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -229,7 +229,7 @@ obj-i386-$(CONFIG_KVM) += kvmclock.o
 obj-i386-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
 
 # shared objects
-obj-ppc-y = ppc.o
+obj-ppc-y = ppc.o ppc_booke.o
 obj-ppc-y += vga.o
 # PREP target
 obj-ppc-y += i8259.o mc146818rtc.o
diff --git a/hw/ppc.c b/hw/ppc.c
index 8870748..25b59dd 100644
--- a/hw/ppc.c
+++ b/hw/ppc.c
@@ -50,7 +50,7 @@
 static void cpu_ppc_tb_stop (CPUState *env);
 static void cpu_ppc_tb_start (CPUState *env);
 
-static void ppc_set_irq (CPUState *env, int n_IRQ, int level)
+void ppc_set_irq(CPUState *env, int n_IRQ, int level)
 {
     unsigned int old_pending = env->pending_interrupts;
 
@@ -423,25 +423,8 @@ void ppce500_irq_init (CPUState *env)
 }
 /*****************************************************************************/
 /* PowerPC time base and decrementer emulation */
-struct ppc_tb_t {
-    /* Time base management */
-    int64_t  tb_offset;    /* Compensation                    */
-    int64_t  atb_offset;   /* Compensation                    */
-    uint32_t tb_freq;      /* TB frequency                    */
-    /* Decrementer management */
-    uint64_t decr_next;    /* Tick for next decr interrupt    */
-    uint32_t decr_freq;    /* decrementer frequency           */
-    struct QEMUTimer *decr_timer;
-    /* Hypervisor decrementer management */
-    uint64_t hdecr_next;    /* Tick for next hdecr interrupt  */
-    struct QEMUTimer *hdecr_timer;
-    uint64_t purr_load;
-    uint64_t purr_start;
-    void *opaque;
-};
 
-static inline uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk,
-                                      int64_t tb_offset)
+uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk, int64_t tb_offset)
 {
     /* TB time in tb periods */
     return muldiv64(vmclk, tb_env->tb_freq, get_ticks_per_sec()) + tb_offset;
@@ -611,10 +594,13 @@ static inline uint32_t _cpu_ppc_load_decr(CPUState *env, uint64_t next)
     int64_t diff;
 
     diff = next - qemu_get_clock_ns(vm_clock);
-    if (diff >= 0)
+    if (diff >= 0) {
         decr = muldiv64(diff, tb_env->decr_freq, get_ticks_per_sec());
-    else
+    } else if (tb_env->flags & PPC_TIMER_BOOKE) {
+        decr = 0;
+    }  else {
         decr = -muldiv64(-diff, tb_env->decr_freq, get_ticks_per_sec());
+    }
     LOG_TB("%s: %08" PRIx32 "\n", __func__, decr);
 
     return decr;
@@ -678,18 +664,24 @@ static void __cpu_ppc_store_decr (CPUState *env, uint64_t *nextp,
                 decr, value);
     now = qemu_get_clock_ns(vm_clock);
     next = now + muldiv64(value, get_ticks_per_sec(), tb_env->decr_freq);
-    if (is_excp)
+    if (is_excp) {
         next += *nextp - now;
-    if (next == now)
+    }
+    if (next == now) {
         next++;
+    }
     *nextp = next;
     /* Adjust timer */
     qemu_mod_timer(timer, next);
-    /* If we set a negative value and the decrementer was positive,
-     * raise an exception.
+
+    /* If we set a negative value and the decrementer was positive, raise an
+     * exception.
      */
-    if ((value & 0x80000000) && !(decr & 0x80000000))
+    if ((tb_env->flags & PPC_DECR_UNDERFLOW_TRIGGERED)
+        && (value & 0x80000000)
+        && !(decr & 0x80000000)) {
         (*raise_excp)(env);
+    }
 }
 
 static inline void _cpu_ppc_store_decr(CPUState *env, uint32_t decr,
@@ -763,6 +755,7 @@ clk_setup_cb cpu_ppc_tb_init (CPUState *env, uint32_t freq)
 
     tb_env = g_malloc0(sizeof(ppc_tb_t));
     env->tb_env = tb_env;
+    tb_env->flags = PPC_DECR_UNDERFLOW_TRIGGERED;
     /* Create new timer */
     tb_env->decr_timer = qemu_new_timer_ns(vm_clock, &cpu_ppc_decr_cb, env);
     if (0) {
@@ -806,11 +799,11 @@ uint32_t cpu_ppc601_load_rtcl (CPUState *env)
 }
 
 /*****************************************************************************/
-/* Embedded PowerPC timers */
+/* PowerPC 40x timers */
 
 /* PIT, FIT & WDT */
-typedef struct ppcemb_timer_t ppcemb_timer_t;
-struct ppcemb_timer_t {
+typedef struct ppc40x_timer_t ppc40x_timer_t;
+struct ppc40x_timer_t {
     uint64_t pit_reload;  /* PIT auto-reload value        */
     uint64_t fit_next;    /* Tick for next FIT interrupt  */
     struct QEMUTimer *fit_timer;
@@ -826,12 +819,12 @@ static void cpu_4xx_fit_cb (void *opaque)
 {
     CPUState *env;
     ppc_tb_t *tb_env;
-    ppcemb_timer_t *ppcemb_timer;
+    ppc40x_timer_t *ppc40x_timer;
     uint64_t now, next;
 
     env = opaque;
     tb_env = env->tb_env;
-    ppcemb_timer = tb_env->opaque;
+    ppc40x_timer = tb_env->opaque;
     now = qemu_get_clock_ns(vm_clock);
     switch ((env->spr[SPR_40x_TCR] >> 24) & 0x3) {
     case 0:
@@ -853,7 +846,7 @@ static void cpu_4xx_fit_cb (void *opaque)
     next = now + muldiv64(next, get_ticks_per_sec(), tb_env->tb_freq);
     if (next == now)
         next++;
-    qemu_mod_timer(ppcemb_timer->fit_timer, next);
+    qemu_mod_timer(ppc40x_timer->fit_timer, next);
     env->spr[SPR_40x_TSR] |= 1 << 26;
     if ((env->spr[SPR_40x_TCR] >> 23) & 0x1)
         ppc_set_irq(env, PPC_INTERRUPT_FIT, 1);
@@ -865,11 +858,11 @@ static void cpu_4xx_fit_cb (void *opaque)
 /* Programmable interval timer */
 static void start_stop_pit (CPUState *env, ppc_tb_t *tb_env, int is_excp)
 {
-    ppcemb_timer_t *ppcemb_timer;
+    ppc40x_timer_t *ppc40x_timer;
     uint64_t now, next;
 
-    ppcemb_timer = tb_env->opaque;
-    if (ppcemb_timer->pit_reload <= 1 ||
+    ppc40x_timer = tb_env->opaque;
+    if (ppc40x_timer->pit_reload <= 1 ||
         !((env->spr[SPR_40x_TCR] >> 26) & 0x1) ||
         (is_excp && !((env->spr[SPR_40x_TCR] >> 22) & 0x1))) {
         /* Stop PIT */
@@ -877,9 +870,9 @@ static void start_stop_pit (CPUState *env, ppc_tb_t *tb_env, int is_excp)
         qemu_del_timer(tb_env->decr_timer);
     } else {
         LOG_TB("%s: start PIT %016" PRIx64 "\n",
-                    __func__, ppcemb_timer->pit_reload);
+                    __func__, ppc40x_timer->pit_reload);
         now = qemu_get_clock_ns(vm_clock);
-        next = now + muldiv64(ppcemb_timer->pit_reload,
+        next = now + muldiv64(ppc40x_timer->pit_reload,
                               get_ticks_per_sec(), tb_env->decr_freq);
         if (is_excp)
             next += tb_env->decr_next - now;
@@ -894,21 +887,21 @@ static void cpu_4xx_pit_cb (void *opaque)
 {
     CPUState *env;
     ppc_tb_t *tb_env;
-    ppcemb_timer_t *ppcemb_timer;
+    ppc40x_timer_t *ppc40x_timer;
 
     env = opaque;
     tb_env = env->tb_env;
-    ppcemb_timer = tb_env->opaque;
+    ppc40x_timer = tb_env->opaque;
     env->spr[SPR_40x_TSR] |= 1 << 27;
     if ((env->spr[SPR_40x_TCR] >> 26) & 0x1)
-        ppc_set_irq(env, ppcemb_timer->decr_excp, 1);
+        ppc_set_irq(env, ppc40x_timer->decr_excp, 1);
     start_stop_pit(env, tb_env, 1);
     LOG_TB("%s: ar %d ir %d TCR " TARGET_FMT_lx " TSR " TARGET_FMT_lx " "
            "%016" PRIx64 "\n", __func__,
            (int)((env->spr[SPR_40x_TCR] >> 22) & 0x1),
            (int)((env->spr[SPR_40x_TCR] >> 26) & 0x1),
            env->spr[SPR_40x_TCR], env->spr[SPR_40x_TSR],
-           ppcemb_timer->pit_reload);
+           ppc40x_timer->pit_reload);
 }
 
 /* Watchdog timer */
@@ -916,12 +909,12 @@ static void cpu_4xx_wdt_cb (void *opaque)
 {
     CPUState *env;
     ppc_tb_t *tb_env;
-    ppcemb_timer_t *ppcemb_timer;
+    ppc40x_timer_t *ppc40x_timer;
     uint64_t now, next;
 
     env = opaque;
     tb_env = env->tb_env;
-    ppcemb_timer = tb_env->opaque;
+    ppc40x_timer = tb_env->opaque;
     now = qemu_get_clock_ns(vm_clock);
     switch ((env->spr[SPR_40x_TCR] >> 30) & 0x3) {
     case 0:
@@ -948,13 +941,13 @@ static void cpu_4xx_wdt_cb (void *opaque)
     switch ((env->spr[SPR_40x_TSR] >> 30) & 0x3) {
     case 0x0:
     case 0x1:
-        qemu_mod_timer(ppcemb_timer->wdt_timer, next);
-        ppcemb_timer->wdt_next = next;
+        qemu_mod_timer(ppc40x_timer->wdt_timer, next);
+        ppc40x_timer->wdt_next = next;
         env->spr[SPR_40x_TSR] |= 1 << 31;
         break;
     case 0x2:
-        qemu_mod_timer(ppcemb_timer->wdt_timer, next);
-        ppcemb_timer->wdt_next = next;
+        qemu_mod_timer(ppc40x_timer->wdt_timer, next);
+        ppc40x_timer->wdt_next = next;
         env->spr[SPR_40x_TSR] |= 1 << 30;
         if ((env->spr[SPR_40x_TCR] >> 27) & 0x1)
             ppc_set_irq(env, PPC_INTERRUPT_WDT, 1);
@@ -982,12 +975,12 @@ static void cpu_4xx_wdt_cb (void *opaque)
 void store_40x_pit (CPUState *env, target_ulong val)
 {
     ppc_tb_t *tb_env;
-    ppcemb_timer_t *ppcemb_timer;
+    ppc40x_timer_t *ppc40x_timer;
 
     tb_env = env->tb_env;
-    ppcemb_timer = tb_env->opaque;
+    ppc40x_timer = tb_env->opaque;
     LOG_TB("%s val" TARGET_FMT_lx "\n", __func__, val);
-    ppcemb_timer->pit_reload = val;
+    ppc40x_timer->pit_reload = val;
     start_stop_pit(env, tb_env, 0);
 }
 
@@ -996,31 +989,7 @@ target_ulong load_40x_pit (CPUState *env)
     return cpu_ppc_load_decr(env);
 }
 
-void store_booke_tsr (CPUState *env, target_ulong val)
-{
-    ppc_tb_t *tb_env = env->tb_env;
-    ppcemb_timer_t *ppcemb_timer;
-
-    ppcemb_timer = tb_env->opaque;
-
-    LOG_TB("%s: val " TARGET_FMT_lx "\n", __func__, val);
-    env->spr[SPR_40x_TSR] &= ~(val & 0xFC000000);
-    if (val & 0x80000000)
-        ppc_set_irq(env, ppcemb_timer->decr_excp, 0);
-}
-
-void store_booke_tcr (CPUState *env, target_ulong val)
-{
-    ppc_tb_t *tb_env;
-
-    tb_env = env->tb_env;
-    LOG_TB("%s: val " TARGET_FMT_lx "\n", __func__, val);
-    env->spr[SPR_40x_TCR] = val & 0xFFC00000;
-    start_stop_pit(env, tb_env, 1);
-    cpu_4xx_wdt_cb(env);
-}
-
-static void ppc_emb_set_tb_clk (void *opaque, uint32_t freq)
+static void ppc_40x_set_tb_clk (void *opaque, uint32_t freq)
 {
     CPUState *env = opaque;
     ppc_tb_t *tb_env = env->tb_env;
@@ -1032,30 +1001,31 @@ static void ppc_emb_set_tb_clk (void *opaque, uint32_t freq)
     /* XXX: we should also update all timers */
 }
 
-clk_setup_cb ppc_emb_timers_init (CPUState *env, uint32_t freq,
+clk_setup_cb ppc_40x_timers_init (CPUState *env, uint32_t freq,
                                   unsigned int decr_excp)
 {
     ppc_tb_t *tb_env;
-    ppcemb_timer_t *ppcemb_timer;
+    ppc40x_timer_t *ppc40x_timer;
 
     tb_env = g_malloc0(sizeof(ppc_tb_t));
     env->tb_env = tb_env;
-    ppcemb_timer = g_malloc0(sizeof(ppcemb_timer_t));
+    tb_env->flags = PPC_DECR_UNDERFLOW_TRIGGERED;
+    ppc40x_timer = g_malloc0(sizeof(ppc40x_timer_t));
     tb_env->tb_freq = freq;
     tb_env->decr_freq = freq;
-    tb_env->opaque = ppcemb_timer;
+    tb_env->opaque = ppc40x_timer;
     LOG_TB("%s freq %" PRIu32 "\n", __func__, freq);
-    if (ppcemb_timer != NULL) {
+    if (ppc40x_timer != NULL) {
         /* We use decr timer for PIT */
         tb_env->decr_timer = qemu_new_timer_ns(vm_clock, &cpu_4xx_pit_cb, env);
-        ppcemb_timer->fit_timer =
+        ppc40x_timer->fit_timer =
             qemu_new_timer_ns(vm_clock, &cpu_4xx_fit_cb, env);
-        ppcemb_timer->wdt_timer =
+        ppc40x_timer->wdt_timer =
             qemu_new_timer_ns(vm_clock, &cpu_4xx_wdt_cb, env);
-        ppcemb_timer->decr_excp = decr_excp;
+        ppc40x_timer->decr_excp = decr_excp;
     }
 
-    return &ppc_emb_set_tb_clk;
+    return &ppc_40x_set_tb_clk;
 }
 
 /*****************************************************************************/
diff --git a/hw/ppc.h b/hw/ppc.h
index 3ccf134..9f91170 100644
--- a/hw/ppc.h
+++ b/hw/ppc.h
@@ -1,3 +1,5 @@
+void ppc_set_irq (CPUState *env, int n_IRQ, int level);
+
 /* PowerPC hardware exceptions management helpers */
 typedef void (*clk_setup_cb)(void *opaque, uint32_t freq);
 typedef struct clk_setup_t clk_setup_t;
@@ -11,6 +13,36 @@ static inline void clk_setup (clk_setup_t *clk, uint32_t freq)
         (*clk->cb)(clk->opaque, freq);
 }
 
+struct ppc_tb_t {
+    /* Time base management */
+    int64_t  tb_offset;    /* Compensation                    */
+    int64_t  atb_offset;   /* Compensation                    */
+    uint32_t tb_freq;      /* TB frequency                    */
+    /* Decrementer management */
+    uint64_t decr_next;    /* Tick for next decr interrupt    */
+    uint32_t decr_freq;    /* decrementer frequency           */
+    struct QEMUTimer *decr_timer;
+    /* Hypervisor decrementer management */
+    uint64_t hdecr_next;    /* Tick for next hdecr interrupt  */
+    struct QEMUTimer *hdecr_timer;
+    uint64_t purr_load;
+    uint64_t purr_start;
+    void *opaque;
+    uint32_t flags;
+};
+
+/* PPC Timers flags */
+#define PPC_TIMER_BOOKE              (1 << 0) /* Enable Booke support */
+#define PPC_TIMER_E500               (1 << 1) /* Enable e500 support */
+#define PPC_DECR_UNDERFLOW_TRIGGERED (1 << 2) /* Decr interrupt triggered when
+                                               * the most significant bit
+                                               * changes from 0 to 1.
+                                               */
+#define PPC_DECR_ZERO_TRIGGERED      (1 << 3) /* Decr interrupt triggered when
+                                               * the decrementer reaches zero.
+                                               */
+
+uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk, int64_t tb_offset);
 clk_setup_cb cpu_ppc_tb_init (CPUState *env, uint32_t freq);
 /* Embedded PowerPC DCR management */
 typedef uint32_t (*dcr_read_cb)(void *opaque, int dcrn);
@@ -19,7 +51,7 @@ int ppc_dcr_init (CPUState *env, int (*dcr_read_error)(int dcrn),
                   int (*dcr_write_error)(int dcrn));
 int ppc_dcr_register (CPUState *env, int dcrn, void *opaque,
                       dcr_read_cb drc_read, dcr_write_cb dcr_write);
-clk_setup_cb ppc_emb_timers_init (CPUState *env, uint32_t freq,
+clk_setup_cb ppc_40x_timers_init (CPUState *env, uint32_t freq,
                                   unsigned int decr_excp);
 
 /* Embedded PowerPC reset */
@@ -55,3 +87,6 @@ enum {
 #define FW_CFG_PPC_KVM_PID      (FW_CFG_ARCH_LOCAL + 0x07)
 
 #define PPC_SERIAL_MM_BAUDBASE 399193
+
+/* ppc_booke.c */
+void ppc_booke_timers_init(CPUState *env, uint32_t freq, uint32_t flags);
diff --git a/hw/ppc4xx_devs.c b/hw/ppc4xx_devs.c
index 349f046..d18caa4 100644
--- a/hw/ppc4xx_devs.c
+++ b/hw/ppc4xx_devs.c
@@ -56,7 +56,7 @@ CPUState *ppc4xx_init (const char *cpu_model,
     cpu_clk->cb = NULL; /* We don't care about CPU clock frequency changes */
     cpu_clk->opaque = env;
     /* Set time-base frequency to sysclk */
-    tb_clk->cb = ppc_emb_timers_init(env, sysclk, PPC_INTERRUPT_PIT);
+    tb_clk->cb = ppc_40x_timers_init(env, sysclk, PPC_INTERRUPT_PIT);
     tb_clk->opaque = env;
     ppc_dcr_init(env, NULL, NULL);
     /* Register qemu callbacks */
diff --git a/hw/ppc_booke.c b/hw/ppc_booke.c
new file mode 100644
index 0000000..3e2fff5
--- /dev/null
+++ b/hw/ppc_booke.c
@@ -0,0 +1,266 @@
+/*
+ * QEMU PowerPC Booke hardware System Emulator
+ *
+ * Copyright (c) 2011 AdaCore
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "hw.h"
+#include "ppc.h"
+#include "qemu-timer.h"
+#include "sysemu.h"
+#include "nvram.h"
+#include "qemu-log.h"
+#include "loader.h"
+
+
+/* Timer Control Register */
+
+#define TCR_WP_SHIFT  30        /* Watchdog Timer Period */
+#define TCR_WP_MASK   (0x3 << TCR_WP_SHIFT)
+#define TCR_WRC_SHIFT 28        /* Watchdog Timer Reset Control */
+#define TCR_WRC_MASK  (0x3 << TCR_WRC_SHIFT)
+#define TCR_WIE       (1 << 27) /* Watchdog Timer Interrupt Enable */
+#define TCR_DIE       (1 << 26) /* Decrementer Interrupt Enable */
+#define TCR_FP_SHIFT  24        /* Fixed-Interval Timer Period */
+#define TCR_FP_MASK   (0x3 << TCR_FP_SHIFT)
+#define TCR_FIE       (1 << 23) /* Fixed-Interval Timer Interrupt Enable */
+#define TCR_ARE       (1 << 22) /* Auto-Reload Enable */
+
+/* Timer Control Register (e500 specific fields) */
+
+#define TCR_E500_FPEXT_SHIFT 13 /* Fixed-Interval Timer Period Extension */
+#define TCR_E500_FPEXT_MASK  (0xf << TCR_E500_FPEXT_SHIFT)
+#define TCR_E500_WPEXT_SHIFT 17 /* Watchdog Timer Period Extension */
+#define TCR_E500_WPEXT_MASK  (0xf << TCR_E500_WPEXT_SHIFT)
+
+/* Timer Status Register  */
+
+#define TSR_FIS       (1 << 26) /* Fixed-Interval Timer Interrupt Status */
+#define TSR_DIS       (1 << 27) /* Decrementer Interrupt Status */
+#define TSR_WRS_SHIFT 28        /* Watchdog Timer Reset Status */
+#define TSR_WRS_MASK  (0x3 << TSR_WRS_SHIFT)
+#define TSR_WIS       (1 << 30) /* Watchdog Timer Interrupt Status */
+#define TSR_ENW       (1 << 31) /* Enable Next Watchdog Timer */
+
+typedef struct booke_timer_t booke_timer_t;
+struct booke_timer_t {
+
+    uint64_t fit_next;
+    struct QEMUTimer *fit_timer;
+
+    uint64_t wdt_next;
+    struct QEMUTimer *wdt_timer;
+
+    uint32_t flags;
+};
+
+static void booke_update_irq(CPUState *env)
+{
+    ppc_set_irq(env, PPC_INTERRUPT_DECR,
+                (env->spr[SPR_BOOKE_TSR] & TSR_DIS
+                 && env->spr[SPR_BOOKE_TCR] & TCR_DIE));
+
+    ppc_set_irq(env, PPC_INTERRUPT_WDT,
+                (env->spr[SPR_BOOKE_TSR] & TSR_WIS
+                 && env->spr[SPR_BOOKE_TCR] & TCR_WIE));
+
+    ppc_set_irq(env, PPC_INTERRUPT_FIT,
+                (env->spr[SPR_BOOKE_TSR] & TSR_FIS
+                 && env->spr[SPR_BOOKE_TCR] & TCR_FIE));
+}
+
+/* Return the location of the bit of time base at which the FIT will raise an
+   interrupt */
+static uint8_t booke_get_fit_target(CPUState *env, ppc_tb_t *tb_env)
+{
+    uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;
+
+    if (tb_env->flags & PPC_TIMER_E500) {
+        /* e500 Fixed-interval timer period extension */
+        uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
+            >> TCR_E500_FPEXT_SHIFT;
+        fp = 63 - (fp | fpext << 2);
+    } else {
+        fp = env->fit_period[fp];
+    }
+
+    return fp;
+}
+
+/* Return the location of the bit of time base at which the WDT will raise an
+   interrupt */
+static uint8_t booke_get_wdt_target(CPUState *env, ppc_tb_t *tb_env)
+{
+    uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;
+
+    if (tb_env->flags & PPC_TIMER_E500) {
+        /* e500 Watchdog timer period extension */
+        uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
+            >> TCR_E500_WPEXT_SHIFT;
+        wp = 63 - (wp | wpext << 2);
+    } else {
+        wp = env->wdt_period[wp];
+    }
+
+    return wp;
+}
+
+static void booke_update_fixed_timer(CPUState         *env,
+                                     uint8_t           target_bit,
+                                     uint64_t          *next,
+                                     struct QEMUTimer *timer)
+{
+    ppc_tb_t *tb_env = env->tb_env;
+    uint64_t lapse;
+    uint64_t tb;
+    uint64_t period = 1 << (target_bit + 1);
+    uint64_t now;
+
+    now = qemu_get_clock_ns(vm_clock);
+    tb  = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
+
+    lapse = period - ((tb - (1 << target_bit)) & (period - 1));
+
+    *next = now + muldiv64(lapse, get_ticks_per_sec(), tb_env->tb_freq);
+
+    /* XXX: If expire time is now. We can't run the callback because we don't
+     * have access to it. So we just set the timer one nanosecond later.
+     */
+
+    if (*next == now) {
+        (*next)++;
+    }
+
+    qemu_mod_timer(timer, *next);
+}
+
+static void booke_decr_cb(void *opaque)
+{
+    CPUState *env;
+    ppc_tb_t *tb_env;
+    booke_timer_t *booke_timer;
+
+    env = opaque;
+    tb_env = env->tb_env;
+    booke_timer = tb_env->opaque;
+    env->spr[SPR_BOOKE_TSR] |= TSR_DIS;
+
+    booke_update_irq(env);
+
+    if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
+        /* Auto Reload */
+        cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
+    }
+}
+
+static void booke_fit_cb(void *opaque)
+{
+    CPUState *env;
+    ppc_tb_t *tb_env;
+    booke_timer_t *booke_timer;
+
+    env = opaque;
+    tb_env = env->tb_env;
+    booke_timer = tb_env->opaque;
+    env->spr[SPR_BOOKE_TSR] |= TSR_FIS;
+
+    booke_update_irq(env);
+
+    booke_update_fixed_timer(env,
+                             booke_get_fit_target(env, tb_env),
+                             &booke_timer->fit_next,
+                             booke_timer->fit_timer);
+}
+
+static void booke_wdt_cb(void *opaque)
+{
+    CPUState *env;
+    ppc_tb_t *tb_env;
+    booke_timer_t *booke_timer;
+
+    env = opaque;
+    tb_env = env->tb_env;
+    booke_timer = tb_env->opaque;
+
+    /* TODO: There's lots of complicated stuff to do here */
+
+    booke_update_irq(env);
+
+    booke_update_fixed_timer(env,
+                             booke_get_wdt_target(env, tb_env),
+                             &booke_timer->wdt_next,
+                             booke_timer->wdt_timer);
+}
+
+void store_booke_tsr(CPUState *env, target_ulong val)
+{
+    ppc_tb_t *tb_env = env->tb_env;
+    booke_timer_t *booke_timer;
+
+    booke_timer = tb_env->opaque;
+
+    env->spr[SPR_BOOKE_TSR] &= ~val;
+
+    booke_update_irq(env);
+}
+
+void store_booke_tcr(CPUState *env, target_ulong val)
+{
+    ppc_tb_t *tb_env = env->tb_env;
+    booke_timer_t *booke_timer = tb_env->opaque;
+
+    tb_env = env->tb_env;
+    env->spr[SPR_BOOKE_TCR] = val;
+
+    booke_update_irq(env);
+
+    booke_update_fixed_timer(env,
+                             booke_get_fit_target(env, tb_env),
+                             &booke_timer->fit_next,
+                             booke_timer->fit_timer);
+
+    booke_update_fixed_timer(env,
+                             booke_get_wdt_target(env, tb_env),
+                             &booke_timer->wdt_next,
+                             booke_timer->wdt_timer);
+
+}
+
+void ppc_booke_timers_init(CPUState *env, uint32_t freq, uint32_t flags)
+{
+    ppc_tb_t *tb_env;
+    booke_timer_t *booke_timer;
+
+    tb_env      = g_malloc0(sizeof(ppc_tb_t));
+    booke_timer = g_malloc0(sizeof(booke_timer_t));
+
+    env->tb_env = tb_env;
+    tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;
+
+    tb_env->tb_freq    = freq;
+    tb_env->decr_freq  = freq;
+    tb_env->opaque     = booke_timer;
+    tb_env->decr_timer = qemu_new_timer_ns(vm_clock, &booke_decr_cb, env);
+
+    booke_timer->fit_timer =
+        qemu_new_timer_ns(vm_clock, &booke_fit_cb, env);
+    booke_timer->wdt_timer =
+        qemu_new_timer_ns(vm_clock, &booke_wdt_cb, env);
+}
diff --git a/hw/ppce500_mpc8544ds.c b/hw/ppce500_mpc8544ds.c
index 8095516..f00367e 100644
--- a/hw/ppce500_mpc8544ds.c
+++ b/hw/ppce500_mpc8544ds.c
@@ -268,11 +268,7 @@ static void mpc8544ds_init(ram_addr_t ram_size,
         irqs[i][OPENPIC_OUTPUT_CINT] = input[PPCE500_INPUT_CINT];
         env->spr[SPR_BOOKE_PIR] = env->cpu_index = i;
 
-        /* XXX register timer? */
-        ppc_emb_timers_init(env, 400000000, PPC_INTERRUPT_DECR);
-        ppc_dcr_init(env, NULL, NULL);
-        /* XXX Enable DEC interrupts - probably wrong in the backend */
-        env->spr[SPR_40x_TCR] = 1 << 26;
+        ppc_booke_timers_init(env, 400000000, PPC_TIMER_E500);
 
         /* Register reset handler */
         if (!i) {
diff --git a/hw/virtex_ml507.c b/hw/virtex_ml507.c
index 7459b0b..66df27a 100644
--- a/hw/virtex_ml507.c
+++ b/hw/virtex_ml507.c
@@ -81,7 +81,6 @@ static void mmubooke_create_initial_mapping(CPUState *env,
 static CPUState *ppc440_init_xilinx(ram_addr_t *ram_size,
                                     int do_init,
                                     const char *cpu_model,
-                                    clk_setup_t *cpu_clk, clk_setup_t *tb_clk,
                                     uint32_t sysclk)
 {
     CPUState *env;
@@ -93,11 +92,7 @@ static CPUState *ppc440_init_xilinx(ram_addr_t *ram_size,
         exit(1);
     }
 
-    cpu_clk->cb = NULL; /* We don't care about CPU clock frequency changes */
-    cpu_clk->opaque = env;
-    /* Set time-base frequency to sysclk */
-    tb_clk->cb = ppc_emb_timers_init(env, sysclk, PPC_INTERRUPT_DECR);
-    tb_clk->opaque = env;
+    ppc_booke_timers_init(env, sysclk, 0/* no flags */);
 
     ppc_dcr_init(env, NULL, NULL);
 
@@ -197,7 +192,6 @@ static void virtex_init(ram_addr_t ram_size,
     DriveInfo *dinfo;
     ram_addr_t phys_ram;
     qemu_irq irq[32], *cpu_irq;
-    clk_setup_t clk_setup[7];
     int kernel_size;
     int i;
 
@@ -207,8 +201,7 @@ static void virtex_init(ram_addr_t ram_size,
     }
 
     memset(clk_setup, 0, sizeof(clk_setup));
-    env = ppc440_init_xilinx(&ram_size, 1, cpu_model, &clk_setup[0],
-                             &clk_setup[1], 400000000);
+    env = ppc440_init_xilinx(&ram_size, 1, cpu_model, 400000000);
     qemu_register_reset(main_cpu_reset, env);
 
     phys_ram = qemu_ram_alloc(NULL, "ram", ram_size);
diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index 3f4af22..3f77e30 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -1018,8 +1018,35 @@ struct CPUPPCState {
 #if !defined(CONFIG_USER_ONLY)
     void *load_info;    /* Holds boot loading state.  */
 #endif
+
+    /* booke timers */
+
+    /* Specifies bit locations of the Time Base used to signal a fixed timer
+     * exception on a transition from 0 to 1. (watchdog or fixed-interval timer)
+     *
+     * 0 selects the least significant bit.
+     * 63 selects the most significant bit.
+     */
+    uint8_t fit_period[4];
+    uint8_t wdt_period[4];
 };
 
+#define SET_FIT_PERIOD(a_, b_, c_, d_)          \
+do {                                            \
+    env->fit_period[0] = (a_);                  \
+    env->fit_period[1] = (b_);                  \
+    env->fit_period[2] = (c_);                  \
+    env->fit_period[3] = (d_);                  \
+ } while (0)
+
+#define SET_WDT_PERIOD(a_, b_, c_, d_)          \
+do {                                            \
+    env->wdt_period[0] = (a_);                  \
+    env->wdt_period[1] = (b_);                  \
+    env->wdt_period[2] = (c_);                  \
+    env->wdt_period[3] = (d_);                  \
+ } while (0)
+
 #if !defined(CONFIG_USER_ONLY)
 /* Context used internally during MMU translations */
 typedef struct mmu_ctx_t mmu_ctx_t;
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index d09c7ca..ca0d852 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -3266,6 +3266,9 @@ static void init_proc_401 (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* PowerPC 401x2                                                             */
@@ -3304,6 +3307,9 @@ static void init_proc_401x2 (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* PowerPC 401x3                                                             */
@@ -3337,6 +3343,9 @@ static void init_proc_401x3 (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* IOP480                                                                    */
@@ -3375,6 +3384,9 @@ static void init_proc_IOP480 (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(8, 12, 16, 20);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* PowerPC 403                                                               */
@@ -3405,6 +3417,9 @@ static void init_proc_403 (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(8, 12, 16, 20);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* PowerPC 403 GCX                                                           */
@@ -3455,6 +3470,9 @@ static void init_proc_403GCX (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(8, 12, 16, 20);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* PowerPC 405                                                               */
@@ -3504,6 +3522,9 @@ static void init_proc_405 (CPUPPCState *env)
     env->icache_line_size = 32;
     /* Allocate hardware IRQ controller */
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(8, 12, 16, 20);
+    SET_WDT_PERIOD(16, 20, 24, 28);
 }
 
 /* PowerPC 440 EP                                                            */
@@ -3586,6 +3607,9 @@ static void init_proc_440EP (CPUPPCState *env)
     env->dcache_line_size = 32;
     env->icache_line_size = 32;
     /* XXX: TODO: allocate internal IRQ controller */
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(20, 24, 28, 32);
 }
 
 /* PowerPC 440 GP                                                            */
@@ -3650,6 +3674,9 @@ static void init_proc_440GP (CPUPPCState *env)
     env->dcache_line_size = 32;
     env->icache_line_size = 32;
     /* XXX: TODO: allocate internal IRQ controller */
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(20, 24, 28, 32);
 }
 
 /* PowerPC 440x4                                                             */
@@ -3714,6 +3741,9 @@ static void init_proc_440x4 (CPUPPCState *env)
     env->dcache_line_size = 32;
     env->icache_line_size = 32;
     /* XXX: TODO: allocate internal IRQ controller */
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(20, 24, 28, 32);
 }
 
 /* PowerPC 440x5                                                             */
@@ -3795,6 +3825,9 @@ static void init_proc_440x5 (CPUPPCState *env)
     env->dcache_line_size = 32;
     env->icache_line_size = 32;
     ppc40x_irq_init(env);
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(20, 24, 28, 32);
 }
 
 /* PowerPC 460 (guessed)                                                     */
@@ -3883,6 +3916,9 @@ static void init_proc_460 (CPUPPCState *env)
     env->dcache_line_size = 32;
     env->icache_line_size = 32;
     /* XXX: TODO: allocate internal IRQ controller */
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(20, 24, 28, 32);
 }
 
 /* PowerPC 460F (guessed)                                                    */
@@ -3974,6 +4010,9 @@ static void init_proc_460F (CPUPPCState *env)
     env->dcache_line_size = 32;
     env->icache_line_size = 32;
     /* XXX: TODO: allocate internal IRQ controller */
+
+    SET_FIT_PERIOD(12, 16, 20, 24);
+    SET_WDT_PERIOD(20, 24, 28, 32);
 }
 
 /* Freescale 5xx cores (aka RCPU) */
