diff --git a/target-xtensa/cpu.c b/target-xtensa/cpu.c
index d572d56..2b9575f 100644
--- a/target-xtensa/cpu.c
+++ b/target-xtensa/cpu.c
@@ -69,6 +69,7 @@ static void xtensa_cpu_reset(CPUState *s)
             XTENSA_OPTION_ATOMCTL) ? 0x28 : 0x15;
     env->sregs[CONFIGID0] = env->config->configid[0];
     env->sregs[CONFIGID1] = env->config->configid[1];
+    rotate_window_abs(env, env->sregs[WINDOW_BASE]);
 
     env->pending_irq_level = 0;
     reset_mmu(env);
diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
index d0bd9da..5bace52 100644
--- a/target-xtensa/cpu.h
+++ b/target-xtensa/cpu.h
@@ -350,11 +350,11 @@ enum {
 
 typedef struct CPUXtensaState {
     const XtensaConfig *config;
-    uint32_t regs[16];
+    uint32_t *regs;
     uint32_t pc;
     uint32_t sregs[256];
     uint32_t uregs[256];
-    uint32_t phys_regs[MAX_NAREG];
+    uint32_t phys_regs[MAX_NAREG + 12];
     union {
         float32 f32[2];
         float64 f64;
@@ -408,6 +408,7 @@ void xtensa_timer_irq(CPUXtensaState *env, uint32_t id, uint32_t active);
 void xtensa_rearm_ccompare_timer(CPUXtensaState *env);
 int cpu_xtensa_signal_handler(int host_signum, void *pinfo, void *puc);
 void xtensa_cpu_list(FILE *f, fprintf_function cpu_fprintf);
+void rotate_window_abs(CPUXtensaState *env, uint32_t position);
 void xtensa_sync_window_from_phys(CPUXtensaState *env);
 void xtensa_sync_phys_from_window(CPUXtensaState *env);
 uint32_t xtensa_tlb_get_addr_mask(const CPUXtensaState *env, bool dtlb, uint32_t way);
diff --git a/target-xtensa/op_helper.c b/target-xtensa/op_helper.c
index 62fa33d..7f69f4b 100644
--- a/target-xtensa/op_helper.c
+++ b/target-xtensa/op_helper.c
@@ -172,39 +172,6 @@ uint32_t HELPER(nsau)(uint32_t v)
     return v ? clz32(v) : 32;
 }
 
-static void copy_window_from_phys(CPUXtensaState *env,
-        uint32_t window, uint32_t phys, uint32_t n)
-{
-    assert(phys < env->config->nareg);
-    if (phys + n <= env->config->nareg) {
-        memcpy(env->regs + window, env->phys_regs + phys,
-                n * sizeof(uint32_t));
-    } else {
-        uint32_t n1 = env->config->nareg - phys;
-        memcpy(env->regs + window, env->phys_regs + phys,
-                n1 * sizeof(uint32_t));
-        memcpy(env->regs + window + n1, env->phys_regs,
-                (n - n1) * sizeof(uint32_t));
-    }
-}
-
-static void copy_phys_from_window(CPUXtensaState *env,
-        uint32_t phys, uint32_t window, uint32_t n)
-{
-    assert(phys < env->config->nareg);
-    if (phys + n <= env->config->nareg) {
-        memcpy(env->phys_regs + phys, env->regs + window,
-                n * sizeof(uint32_t));
-    } else {
-        uint32_t n1 = env->config->nareg - phys;
-        memcpy(env->phys_regs + phys, env->regs + window,
-                n1 * sizeof(uint32_t));
-        memcpy(env->phys_regs, env->regs + window + n1,
-                (n - n1) * sizeof(uint32_t));
-    }
-}
-
-
 static inline unsigned windowbase_bound(unsigned a, const CPUXtensaState *env)
 {
     return a & (env->config->nareg / 4 - 1);
@@ -217,18 +184,27 @@ static inline unsigned windowstart_bit(unsigned a, const CPUXtensaState *env)
 
 void xtensa_sync_window_from_phys(CPUXtensaState *env)
 {
-    copy_window_from_phys(env, 0, env->sregs[WINDOW_BASE] * 4, 16);
+    if (env->sregs[WINDOW_BASE] * 4 + 16 > env->config->nareg) {
+        memcpy(env->phys_regs + env->config->nareg, env->phys_regs,
+                (env->sregs[WINDOW_BASE] * 4 + 16 - env->config->nareg) *
+                sizeof(uint32_t));
+    }
 }
 
 void xtensa_sync_phys_from_window(CPUXtensaState *env)
 {
-    copy_phys_from_window(env, env->sregs[WINDOW_BASE] * 4, 0, 16);
+    if (env->sregs[WINDOW_BASE] * 4 + 16 > env->config->nareg) {
+        memcpy(env->phys_regs, env->phys_regs + env->config->nareg,
+                (env->sregs[WINDOW_BASE] * 4 + 16 - env->config->nareg) *
+                sizeof(uint32_t));
+    }
 }
 
-static void rotate_window_abs(CPUXtensaState *env, uint32_t position)
+void rotate_window_abs(CPUXtensaState *env, uint32_t position)
 {
     xtensa_sync_phys_from_window(env);
     env->sregs[WINDOW_BASE] = windowbase_bound(position, env);
+    env->regs = env->phys_regs + env->sregs[WINDOW_BASE] * 4;
     xtensa_sync_window_from_phys(env);
 }
 
diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index 9894488..c988511 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -75,6 +75,7 @@ typedef struct DisasContext {
 } DisasContext;
 
 static TCGv_env cpu_env;
+static TCGv_ptr cpu_regs;
 static TCGv_i32 cpu_pc;
 static TCGv_i32 cpu_R[16];
 static TCGv_i32 cpu_FR[16];
@@ -218,12 +219,14 @@ void xtensa_translate_init(void)
     int i;
 
     cpu_env = tcg_global_reg_new_ptr(TCG_AREG0, "env");
+    cpu_regs = tcg_global_mem_new_ptr(cpu_env,
+            offsetof(CPUXtensaState, regs), "regs");
     cpu_pc = tcg_global_mem_new_i32(cpu_env,
             offsetof(CPUXtensaState, pc), "pc");
 
     for (i = 0; i < 16; i++) {
-        cpu_R[i] = tcg_global_mem_new_i32(cpu_env,
-                offsetof(CPUXtensaState, regs[i]),
+        cpu_R[i] = tcg_global_mem_new_i32(cpu_regs,
+                i * sizeof(uint32_t),
                 regnames[i]);
     }
 
