[platform][zynq] debug uart code tweak

-wait until there's a slot in the fifo before writing
-let the target set the debug uart

platform/zynq/debug.c

@@ -26,6 +26,7 @@
 #include <kernel/thread.h>
 #include <platform/debug.h>
 #include <platform/zynq.h>
+#include <target/debugconfig.h>
 #include <reg.h>
 
 #define UART_CR (0x00)
@@ -45,10 +46,47 @@
 #define UART_FLOW_DELAY (0x38)
 #define UART_TX_FIFO_TRIGGER (0x44)
 
-#define UARTREG(reg)  (*REG32(UART0_BASE + (reg)))
+/* DEBUG_UART must be defined to 0 or 1 */
+#if defined(DEBUG_UART) && DEBUG_UART == 0
+#define DEBUG_UART_BASE UART0_BASE
+#elif defined(DEBUG_UART) && DEBUG_UART == 1
+#define DEBUG_UART_BASE UART1_BASE
+#else
+#error define DEBUG_UART to something valid
+#endif
+
+#define UARTREG(reg)  (*REG32(DEBUG_UART_BASE + (reg)))
+
+#if 0
+uboot setup for zynq board
+E0001000:   00000114
+E0001004:   00000020
+E0001008:   00000000
+E000100C:   00000000
+E0001010:   00000000
+E0001014:   00000200
+E0001018:   0000003E
+E000101C:   00000000
+E0001020:   00000020
+E0001024:   00000000
+E0001028:   000000FB
+E000102C:   0000000A
+E0001030:   00000000
+E0001034:   00000006
+E0001038:   00000000
+E000103C:   00000000
+E0001040:   00000000
+E0001044:   00000020
+#endif
 
 void platform_dputc(char c)
 {
+    if (c == '\n')
+        platform_dputc('\r');
+
+    /* spin while fifo is full */
+    while (UARTREG(UART_SR) & (1<<4))
+        ;
     UARTREG(UART_FIFO) = c;
 }
 

target/zynq-qemu/include/target/debugconfig.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2014 Travis Geiselbrecht
+ *
+ * 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.
+ */
+#pragma once
+
+#define DEBUG_UART 0