diff -ur gdb-7.9.orig/sim/lm32/dv-lm32uart.c gdb-7.9/sim/lm32/dv-lm32uart.c
--- gdb-7.9.orig/sim/lm32/dv-lm32uart.c	2015-02-19 05:58:08.000000000 -0600
+++ gdb-7.9/sim/lm32/dv-lm32uart.c	2015-04-01 17:21:09.078882329 -0500
@@ -22,9 +22,6 @@
 #include "hw-main.h"
 #include "sim-assert.h"
 
-#include <stdio.h>
-#include <sys/time.h>
-
 struct lm32uart
 {
   unsigned base;		/* Base address of this UART.  */
@@ -38,6 +35,8 @@
   unsigned char lsr;
   unsigned char msr;
   unsigned char div;
+  int saved_count;
+  char saved_byte;
   struct hw_event *event;
 };
 
@@ -83,6 +82,7 @@
 static void
 do_uart_tx_event (struct hw *me, void *data)
 {
+  SIM_DESC sd = hw_system (me);
   struct lm32uart *uart = hw_data (me);
   char c;
 
@@ -115,7 +115,8 @@
       c &= 0x7f;
       break;
     }
-  printf ("%c", c);
+  sim_io_write_stdout (sd, &c, 1);
+  sim_io_flush_stdout (sd);
 }
 
 static unsigned
@@ -200,6 +201,7 @@
 			 void *dest,
 			 int space, unsigned_word base, unsigned nr_bytes)
 {
+  SIM_DESC sd = hw_system (me);
   struct lm32uart *uart = hw_data (me);
   int uart_reg;
   int value;
@@ -214,7 +216,8 @@
   switch (uart_reg)
     {
     case LM32_UART_RBR:
-      value = getchar ();
+      value = uart->saved_byte;
+      --uart->saved_count;
       uart->lsr &= ~LM32_UART_LSR_RX_RDY;
       break;
     case LM32_UART_IER:
@@ -231,12 +234,10 @@
       break;
     case LM32_UART_LSR:
       /* Check to see if any data waiting in stdin.  */
-      FD_ZERO (&fd);
-      FD_SET (fileno (stdin), &fd);
-      tv.tv_sec = 0;
-      tv.tv_usec = 1;
-      if (select (fileno (stdin) + 1, &fd, NULL, NULL, &tv))
-	uart->lsr |= LM32_UART_LSR_RX_RDY;
+      if (uart->saved_count <= 0)
+        uart->saved_count = sim_io_poll_read (sd, 0/*STDIN*/,
+                                              &uart->saved_byte, 1);
+      uart->lsr |= uart->saved_count ? LM32_UART_LSR_RX_RDY : 0;
       value = uart->lsr;
       break;
     case LM32_UART_MSR: