diff --git a/arch/arm/src/common/up_sigdeliver.c b/arch/arm/src/common/up_sigdeliver.c
index e6a0dfd89f..6738551444 100644
--- a/arch/arm/src/common/up_sigdeliver.c
+++ b/arch/arm/src/common/up_sigdeliver.c
@@ -76,6 +76,7 @@
 
 void up_sigdeliver(void)
 {
+#ifndef CONFIG_DISABLE_SIGNALS
   _TCB  *rtcb = (_TCB*)g_readytorun.head;
   uint32 regs[XCPTCONTEXT_REGS];
   sig_deliver_t sigdeliver;
@@ -132,4 +133,5 @@ void up_sigdeliver(void)
 
   up_ledoff(LED_SIGNAL);
   up_fullcontextrestore(regs);
+#endif
 }
diff --git a/arch/sim/src/up_tapdev.c b/arch/sim/src/up_tapdev.c
index a649c2490b..7e9809e5cb 100644
--- a/arch/sim/src/up_tapdev.c
+++ b/arch/sim/src/up_tapdev.c
@@ -217,10 +217,10 @@ static inline void dump_ethhdr(const char *msg, unsigned char *buf, int buflen)
   lib_rawprintf("        %02x:%02x:%02x:%02x:%02x:%02x %02x:%02x:%02x:%02x:%02x:%02x %02x%02x\n",
                 buf[0], buf[1], buf[2], buf[3], buf[4],  buf[5],
                 buf[6], buf[7], buf[8], buf[9], buf[10], buf[11],
-#if UIP_BYTE_ORDER == UIP_LITTLE_ENDIAN
-                buf[12], buf[13]);
-#else
+#ifdef CONFIG_ENDIAN_BIG
                 buf[13], buf[12]);
+#else
+                buf[12], buf[13]);
 #endif
 }
 #else
diff --git a/arch/sim/src/up_uipdriver.c b/arch/sim/src/up_uipdriver.c
index d7425f82f3..dbc78f9c04 100644
--- a/arch/sim/src/up_uipdriver.c
+++ b/arch/sim/src/up_uipdriver.c
@@ -141,7 +141,7 @@ void uipdriver_loop(void)
 
   /* tapdev_read will return 0 on a timeout event and >0 on a data received event */
 
-  g_sim_dev.d_len = tapdev_read((unsigned char*)g_sim_dev.d_buf, UIP_BUFSIZE);
+  g_sim_dev.d_len = tapdev_read((unsigned char*)g_sim_dev.d_buf, CONFIG_NET_BUFSIZE);
 
   /* Disable preemption through to the following so that it behaves a little more
    * like an interrupt (otherwise, the following logic gets pre-empted an behaves