UART with stdio functions

sam3s_example/Makefile

@@ -67,9 +67,12 @@ OBJ = obj
 # Tool suffix when cross-compiling
 CROSS_COMPILE = arm-none-eabi-
 
+LIBC_PATH=../Baselibc
+
 LIBS = -Wl,--start-group -lgcc -lc -Wl,--end-group
 #LIB_PATH+=-L=/lib/thumb2
 #LIB_PATH+=-L=/../lib/gcc/arm-none-eabi/4.4.1/thumb2
+LIB+=-L=$(LIBC_PATH) -lc
 
 # Compilation tools
 CC = $(CROSS_COMPILE)gcc
@@ -83,6 +86,7 @@ NM = $(CROSS_COMPILE)nm
 # Flags
 INCLUDES  = -Iinclude -Isam3s_examples_include
 INCLUDES += -Icmsis
+INCLUDES += -I$(LIBC_PATH)/include
 #INCLUDES += -I$(LIBRARIES)
 
 CFLAGS += -Wall -Wchar-subscripts -Wcomment -Wformat=2 -Wimplicit-int
@@ -107,7 +111,7 @@ CFLAGS += -Dprintf=iprintf
 CFLAGS += --param max-inline-insns-single=500 -mcpu=cortex-m3 -mthumb # -mfix-cortex-m3-ldrd
 CFLAGS += -ffunction-sections -g $(OPTIMIZATION) $(INCLUDES) -D$(CHIP) -DTRACE_LEVEL=$(TRACE_LEVEL)
 ASFLAGS = -mcpu=cortex-m3 -mthumb -Wall -g $(OPTIMIZATION) $(INCLUDES) -D$(CHIP) -D__ASSEMBLY__
-LDFLAGS = -mcpu=cortex-m3 -mthumb -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--entry=ResetException -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--warn-section-align -Wl,--warn-unresolved-symbols
+LDFLAGS = -mcpu=cortex-m3 -mthumb -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--entry=ResetException -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--warn-section-align -Wl,--warn-unresolved-symbols $(LIB)
 #LD_OPTIONAL=-Wl,--print-gc-sections -Wl,--stats
 
 #-------------------------------------------------------------------------------

sam3s_example/mains/debug_uart_stdlib.c

@@ -0,0 +1,155 @@
+#include "board.h"
+
+#include <stdio.h>
+#include <string.h>
+
+/*----------------------------------------------------------------------------
+ *  *        Definitions
+ *   *----------------------------------------------------------------------------*/
+
+/** Console baudrate always using 115200. */
+#define CONSOLE_BAUDRATE    115200
+/** Usart Hw interface used by the console (UART0). */
+#define CONSOLE_USART       UART0
+/** Usart Hw ID used by the console (UART0). */
+#define CONSOLE_ID          ID_UART0
+/** Pins description corresponding to Rxd,Txd, (UART pins) */
+#define CONSOLE_PINS        {PINS_UART}
+
+/*----------------------------------------------------------------------------
+ *  *        Variables
+ *   *----------------------------------------------------------------------------*/
+
+const Pin redled = {LED_RED, PIOA, ID_PIOA, PIO_OUTPUT_0, PIO_DEFAULT};
+const Pin greenled = {LED_GREEN, PIOA, ID_PIOA, PIO_OUTPUT_0, PIO_DEFAULT};
+
+static const Pin *led;
+
+/** Is Console Initialized. */
+static uint8_t _ucIsConsoleInitialized=0 ;
+
+/**
+ * \brief Configures an USART peripheral with the specified parameters.
+ *
+ * \param baudrate  Baudrate at which the USART should operate (in Hz).
+ * \param masterClock  Frequency of the system master clock (in Hz).
+ */
+extern void UART_Configure( uint32_t baudrate, uint32_t masterClock)
+{
+    const Pin pPins[] = CONSOLE_PINS;
+    Uart *pUart = CONSOLE_USART;
+
+
+    /* Configure PIO */
+    PIO_Configure(pPins, PIO_LISTSIZE(pPins));
+
+    /* Configure PMC */
+/*     PMC_PCER0 : (PMC Offset: 0x0010) Peripheral Clock Enable Register 0 -------- */
+    PMC->PMC_PCER0 = 1 << CONSOLE_ID;
+
+    /* Reset and disable receiver & transmitter */
+    pUart->UART_CR = UART_CR_RSTRX | UART_CR_RSTTX
+                   | UART_CR_RXDIS | UART_CR_TXDIS;
+
+    /* Configure mode */
+    pUart->UART_MR =  UART_MR_PAR_NO;   // No parity
+
+    /* Configure baudrate */
+    /* Asynchronous, no oversampling */
+    // BRG: Baud rate generator
+    pUart->UART_BRGR = (masterClock / baudrate) / 16;
+
+    /* Disable PDC channel */
+    // PDC: Peripheral DMA
+    // TCR: Transfer Control Register
+    pUart->UART_PTCR = UART_PTCR_RXTDIS | UART_PTCR_TXTDIS;
+
+    /* Enable receiver and transmitter */
+    
+    pUart->UART_CR = UART_CR_RXEN | UART_CR_TXEN;
+
+    _ucIsConsoleInitialized=1 ;
+}
+
+
+/**
+ * \brief Outputs a character on the UART line.
+ *
+ * \note This function is synchronous (i.e. uses polling).
+ * \param c  Character to send.
+ */
+extern void UART_PutChar( uint8_t c )
+{
+    Uart *pUart=CONSOLE_USART ;
+
+    if ( !_ucIsConsoleInitialized )
+    {
+        UART_Configure(CONSOLE_BAUDRATE, BOARD_MCK);
+    }
+
+    /* Wait for the transmitter to be ready */
+    // UART_SR: Statzs register
+    while ( (pUart->UART_SR & UART_SR_TXEMPTY) == 0 ) ;
+
+    /* Send character */
+    // THR: transmit holding register
+    pUart->UART_THR=c ;
+
+}
+
+
+
+/**
+ * \brief Input a character from the UART line.
+ *
+ * \note This function is synchronous
+ * \return character received.
+ */
+extern uint32_t UART_GetChar( void )
+{
+    Uart *pUart=CONSOLE_USART ;
+
+    if ( !_ucIsConsoleInitialized )
+    {
+        UART_Configure(CONSOLE_BAUDRATE, BOARD_MCK);
+    }
+
+    while ( (pUart->UART_SR & UART_SR_RXRDY) == 0 ) ;
+
+    return pUart->UART_RHR ;
+}
+
+void Configure_LED() {
+    PIO_Configure(&greenled, PIO_LISTSIZE(greenled));
+    PIO_Configure(&redled, PIO_LISTSIZE(redled));
+    PIO_Set(&redled);
+    PIO_Set(&greenled);
+    led = &redled;
+}
+
+void UART_PutString(char *str, int len) {
+    int i;
+    for (i=0; i<len; i++) {
+        UART_PutChar(*str++);
+    }
+}
+
+int main() {
+    char *cmdp;
+// FIXME: initialize system clock done in lowlevelinit?
+
+    Configure_LED();
+
+    int ret = asprintf(&cmdp, "Clockval: %d\r\n", BOARD_MCK);
+
+    if (ret != strlen(cmdp)){
+         PIO_Clear(&redled);
+    } else {
+         PIO_Clear(&greenled);
+        while (1) {
+            UART_PutString(cmdp, strlen(cmdp));
+        }
+    }
+
+    return 0;
+}