cpu/sam3x8e: made UART0 work by editing syscalls

boards/arduino-due/include/board.h

@@ -43,6 +43,7 @@ extern "C" {
  */
 #define STDIO               UART_0
 #define STDIO_BAUDRATE      (115200U)
+#define STDIO_RX_BUFSIZE    (64U)
 /** @} */
 
 /**

boards/udoo/include/board.h

@@ -44,6 +44,7 @@ extern "C" {
  */
 #define STDIO               UART_0
 #define STDIO_BAUDRATE      (115200U)
+#define STDIO_RX_BUFSIZE    (64U)
 /** @} */
 
 /**

cpu/sam3x8e/Makefile.include

@@ -1,13 +1,21 @@
-
 # this CPU implementation is using the new core/CPU interface
 export CFLAGS += -DCOREIF_NG=1
 
+# export the peripheral drivers to be linked into the final binary
+export USEMODULE += periph
+
+# this CPU implementation makes use of the ringbuffer, so include the lib module
+export USEMODULE += lib
+
 # tell the build system that the CPU depends on the Cortex-M common files
 export USEMODULE += cortex-m3_common
 
 # define path to cortex-m common module, which is needed for this CPU
 export CORTEX_COMMON = $(RIOTCPU)/cortex-m3_common/
 
+# CPU depends on the cortex-m common module, so include it
+include $(CORTEX_COMMON)Makefile.include
+
 # define the linker script to use for this CPU
 export LINKERSCRIPT ?= $(RIOTCPU)/$(CPU)/sam3x8e_linkerscript.ld
 
@@ -18,9 +26,3 @@ export INCLUDES += -I$(RIOTCPU)/$(CPU)/include
 #   Without this the interrupt vectors will not be linked correctly!
 export UNDEF += $(BINDIR)cpu/syscalls.o
 export UNDEF += $(BINDIR)cpu/startup.o
-
-# export the peripheral drivers to be linked into the final binary
-export USEMODULE += periph
-
-# CPU depends on the cortex-m common module, so include it
-include $(CORTEX_COMMON)Makefile.include

cpu/sam3x8e/syscalls.c

@@ -31,21 +31,60 @@
 #include "board.h"
 #include "thread.h"
 #include "kernel.h"
+#include "mutex.h"
+#include "ringbuffer.h"
 #include "irq.h"
 #include "periph/uart.h"
 
+#ifdef MODULE_UART0
+#include "board_uart0.h"
+#endif
+
 /**
  * manage the heap
  */
 extern char _sheap;                 /* start of the heap */
 extern char _eheap;                 /* end of the heap */
 caddr_t heap_top = (caddr_t)&_sheap + 4;
+
+#ifndef MODULE_UART0
+/**
+ * @brief use mutex for waiting on incoming UART chars
+ */
+static mutex_t uart_rx_mutex;
+static char rx_buf_mem[STDIO_RX_BUFSIZE];
+static ringbuffer_t rx_buf;
+#endif
+
+/**
+ * @brief Receive a new character from the UART and put it into the receive buffer
+ */
+void rx_cb(void *arg, char data)
+{
+#ifndef MODULE_UART0
+    (void)arg;
+
+    ringbuffer_add_one(&rx_buf, data);
+    mutex_unlock(&uart_rx_mutex);
+#else
+    if (uart0_handler_pid) {
+        uart0_handle_incoming(data);
+
+        uart0_notify_thread();
+    }
+#endif
+}
+
 /**
  * @brief Initialize NewLib, called by __libc_init_array() from the startup script
  */
 void _init(void)
 {
-    uart_init_blocking(STDIO, STDIO_BAUDRATE);
+#ifndef MODULE_UART0
+    mutex_init(&uart_rx_mutex);
+    ringbuffer_init(&rx_buf, rx_buf_mem, STDIO_RX_BUFSIZE);
+#endif
+    uart_init(STDIO, STDIO_BAUDRATE, rx_cb, 0, 0);
 }
 
 /**
@@ -157,11 +196,16 @@ int _open_r(struct _reent *r, const char *name, int mode)
  */
 int _read_r(struct _reent *r, int fd, void *buffer, unsigned int count)
 {
-    char c;
-    char *buff = (char*)buffer;
-    uart_read_blocking(UART_0, &c);
-    buff[0] = c;
+#ifndef MODULE_UART0
+    while (rx_buf.avail == 0) {
+        mutex_lock(&uart_rx_mutex);
+    }
+    return ringbuffer_get(&rx_buf, (char*)buffer, rx_buf.avail);
+#else
+    char *res = (char*)buffer;
+    res[0] = (char)uart0_readc();
     return 1;
+#endif
 }
 
 /**
@@ -181,9 +225,8 @@ int _read_r(struct _reent *r, int fd, void *buffer, unsigned int count)
  */
 int _write_r(struct _reent *r, int fd, const void *data, unsigned int count)
 {
-    char *c = (char*)data;
     for (int i = 0; i < count; i++) {
-        uart_write_blocking(UART_0, c[i]);
+        uart_write_blocking(UART_0, ((char *)data)[i]);
     }
     return count;
 }