atmel-samd: Support raw repl and soft reset to support ampy.

Closes #1. Also adds TX and RX led support on the Arduino Zero.

atmel-samd/Makefile

@@ -150,6 +150,7 @@ SRC_C = \
 	asf/sam0/utils/cmsis/samd21/source/gcc/startup_samd21.c \
 	asf/sam0/utils/cmsis/samd21/source/system_samd21.c \
 	asf/sam0/utils/syscalls/gcc/syscalls.c \
+	boards/$(BOARD)/init.c \
 	boards/$(BOARD)/pins.c \
 	lib/fatfs/ff.c \
 	lib/fatfs/option/ccsbcs.c \

atmel-samd/boards/arduino_zero/init.c

@@ -8,9 +8,10 @@
  * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
  */
 
-#include <asf.h>
-#include <board.h>
-#include <conf_board.h>
+#include "board.h"
+#include "conf_board.h"
+#include "mpconfigboard.h"
+#include "asf/sam0/drivers/port/port.h"
 
 void board_init(void)
 {
@@ -18,4 +19,13 @@ void board_init(void)
      * for, e.g., the I/O pins. The initialization can rely on application-
      * specific board configuration, found in conf_board.h.
      */
+    struct port_config pin_conf;
+    port_get_config_defaults(&pin_conf);
+
+    pin_conf.direction  = PORT_PIN_DIR_OUTPUT;
+    port_pin_set_config(MICROPY_HW_LED_TX, &pin_conf);
+    port_pin_set_output_level(MICROPY_HW_LED_TX, true);
+
+    port_pin_set_config(MICROPY_HW_LED_RX, &pin_conf);
+    port_pin_set_output_level(MICROPY_HW_LED_RX, true);
 }

atmel-samd/boards/arduino_zero/mpconfigboard.h

@@ -5,3 +5,6 @@
 
 #define MICROPY_HW_BOARD_NAME "Arduino Zero"
 #define MICROPY_HW_MCU_NAME "samd21g18"
+
+#define MICROPY_HW_LED_TX   PIN_PA27
+#define MICROPY_HW_LED_RX   PIN_PB03

atmel-samd/boards/feather_m0_bluefruit_le/init.c

@@ -8,9 +8,8 @@
  * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
  */
 
-#include <asf.h>
-#include <board.h>
-#include <conf_board.h>
+#include "board.h"
+#include "conf_board.h"
 
 void board_init(void)
 {

atmel-samd/main.c

@@ -19,6 +19,7 @@
 #include "asf/sam0/drivers/port/port.h"
 #include "asf/sam0/drivers/sercom/usart/usart.h"
 #include "asf/sam0/drivers/system/system.h"
+#include <board.h>
 
 #include "mpconfigboard.h"
 #include "modmachine_pin.h"
@@ -158,16 +159,7 @@ void init_flash_fs() {
 static char *stack_top;
 static char heap[8192];
 
-int main(int argc, char **argv) {
-    // initialise the cpu and peripherals
-    #if MICROPY_MIN_USE_SAMD21_MCU
-    void samd21_init(void);
-    samd21_init();
-    #endif
-
-    int stack_dummy;
-    stack_top = (char*)&stack_dummy;
-
+void reset_mp() {
     #if MICROPY_ENABLE_GC
     gc_init(heap, heap + sizeof(heap));
     #endif
@@ -176,11 +168,22 @@ int main(int argc, char **argv) {
     MP_STATE_PORT(mp_kbd_exception) = mp_obj_new_exception(&mp_type_KeyboardInterrupt);
 
     pin_init0();
+}
+
+int main(int argc, char **argv) {
+    // initialise the cpu and peripherals
+    #if MICROPY_MIN_USE_SAMD21_MCU
+    void samd21_init(void);
+    samd21_init();
+    #endif
 
     // Initialise the local flash filesystem.
     // Create it if needed, mount in on /flash, and set it as current dir.
     init_flash_fs();
 
+    int stack_dummy;
+    reset_mp();
+
     #if MICROPY_REPL_EVENT_DRIVEN
     pyexec_event_repl_init();
     for (;;) {
@@ -190,10 +193,24 @@ int main(int argc, char **argv) {
         }
     }
     #else
-    pyexec_friendly_repl();
+    // Main script is finished, so now go into REPL mode.
+    // The REPL mode can change, or it can request a soft reset.
+    int exit_code = 0;
+    for (;;) {
+        if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {
+            exit_code = pyexec_raw_repl();
+        } else {
+            exit_code = pyexec_friendly_repl();
+        }
+        if (exit_code == PYEXEC_FORCED_EXIT) {
+            mp_hal_stdout_tx_str("soft reboot\r\n");
+            stack_top = (char*)&stack_dummy;
+            reset_mp();
+        } else if (exit_code != 0) {
+            break;
+        }
+    }
     #endif
-    //do_str("print('hello world!', list(x+1 for x in range(10)), end='eol\\n')", MP_PARSE_SINGLE_INPUT);
-    //do_str("for i in range(10):\r\n  print(i)", MP_PARSE_FILE_INPUT);
     mp_deinit();
     return 0;
 }
@@ -239,7 +256,6 @@ void MP_WEAK __assert_func(const char *file, int line, const char *func, const c
 struct usart_module usart_instance;
 
 void samd21_init(void) {
-
     irq_initialize_vectors();
     cpu_irq_enable();
 
@@ -250,6 +266,8 @@ void samd21_init(void) {
 
     delay_init();
 
+    board_init();
+
     // Uncomment to init PIN_PA17 for debugging.
     // struct port_config pin_conf;
     // port_get_config_defaults(&pin_conf);

atmel-samd/mphalport.c

@@ -2,6 +2,7 @@
 
 #include "asf/common/services/usb/class/cdc/device/udi_cdc.h"
 #include "asf/common2/services/delay/delay.h"
+#include "asf/sam0/drivers/port/port.h"
 #include "asf/sam0/drivers/sercom/usart/usart.h"
 #include "py/mphal.h"
 #include "py/mpstate.h"
@@ -107,12 +108,18 @@ int mp_hal_stdin_rx_chr(void) {
     for (;;) {
         #ifdef USB_REPL
         if (mp_cdc_enabled && usb_rx_count > 0) {
+            #ifdef MICROPY_HW_LED_RX
+            port_pin_toggle_output_level(MICROPY_HW_LED_RX);
+            #endif
             return receive_usb();
         }
         #endif
         #ifdef UART_REPL
         uint16_t temp;
         if (usart_read_wait(&usart_instance, &temp) == STATUS_OK) {
+            #ifdef MICROPY_HW_LED_RX
+            port_pin_toggle_output_level(MICROPY_HW_LED_RX);
+            #endif
             return temp;
         }
         #endif
@@ -123,6 +130,10 @@ int mp_hal_stdin_rx_chr(void) {
 }
 
 void mp_hal_stdout_tx_strn(const char *str, size_t len) {
+    #ifdef MICROPY_HW_LED_TX
+    port_pin_toggle_output_level(MICROPY_HW_LED_TX);
+    #endif
+
     #ifdef UART_REPL
     usart_write_buffer_wait(&usart_instance, (uint8_t*) str, len);
     #endif