[platform] fix the dgetc signature problem
diff --git a/platform/armemu/debug.c b/platform/armemu/debug.c
index 09aabd5..9eea536 100644
--- a/platform/armemu/debug.c
+++ b/platform/armemu/debug.c
@@ -32,15 +32,21 @@
 	*REG8(DEBUG_STDOUT) = c;
 }
 
-int dgetc(char *c)
+int dgetc(char *c, bool wait)
 {
-	int8_t result = (int8_t)*REG8(DEBUG_STDIN);
+	for (;;) {
+		int8_t result = (int8_t)*REG8(DEBUG_STDIN);
 
-	if (result == -1)
-		return -1;
+		if (result == -1) {
+			if (wait)
+				continue;
+			else
+				return -1;
+		}
 
-	*c = (char)result;
-	return 0;
+		*c = (char)result;
+		return 0;
+	}
 }
 
 void debug_dump_regs(void)
diff --git a/platform/integrator/debug.c b/platform/integrator/debug.c
index 0a2e058..1aedf8b 100644
--- a/platform/integrator/debug.c
+++ b/platform/integrator/debug.c
@@ -98,7 +98,7 @@
 	uart_putc(0, c);
 }
 
-int dgetc(char *c)
+int dgetc(char *c, bool wait)
 {
 	int result = uart_getc(0, false);
 
diff --git a/platform/msm_shared/debug.c b/platform/msm_shared/debug.c
index 935d886..9adc4e4 100644
--- a/platform/msm_shared/debug.c
+++ b/platform/msm_shared/debug.c
@@ -55,7 +55,7 @@
 #endif
 }
 
-int dgetc(char *c)
+int dgetc(char *c, bool wait)
 {
 	int n;
 #if WITH_DEBUG_DCC
diff --git a/platform/omap3/debug.c b/platform/omap3/debug.c
index ac6300d..8ddf3b2 100644
--- a/platform/omap3/debug.c
+++ b/platform/omap3/debug.c
@@ -37,7 +37,7 @@
 	uart_putc(DEBUG_UART, c);
 }
 
-int dgetc(char *c)
+int dgetc(char *c, bool wait)
 {
 	int _c;