vfs: code review fixes

- fix typo in readme
- remove unneeded extern declaration
- fix header guard macro
- tabs->spaces in syscalls.c (+1 squashed commit)
- fix minor typos

components/esp32/cpu_start.c

@@ -42,6 +42,7 @@
 #include "esp_spi_flash.h"
 #include "esp_ipc.h"
 #include "esp_log.h"
+#include "esp_vfs_dev.h"
 #include "esp_newlib.h"
 #include "esp_brownout.h"
 #include "esp_int_wdt.h"
@@ -161,6 +162,11 @@ void start_cpu0_default(void)
     esp_task_wdt_init();
 #endif
     esp_setup_syscalls();
+    esp_vfs_dev_uart_register();
+    esp_reent_init(_GLOBAL_REENT);
+    _GLOBAL_REENT->_stdout = fopen("/dev/uart/0", "w"); // use fdopen here?
+    _GLOBAL_REENT->_stderr = _GLOBAL_REENT->_stdout;
+    _GLOBAL_REENT->_stdin  = _GLOBAL_REENT->_stdout;
     do_global_ctors();
     esp_ipc_init();
     spi_flash_init();

components/freertos/tasks.c

@@ -77,6 +77,7 @@ task.h is included from an application file. */
 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
 
 #include "rom/ets_sys.h"
+#include "esp_newlib.h"
 
 /* FreeRTOS includes. */
 #include "FreeRTOS.h"
@@ -962,8 +963,8 @@ UBaseType_t x;
 
 	#if ( configUSE_NEWLIB_REENTRANT == 1 )
 	{
-		/* Initialise this task's Newlib reent structure. */
-		_REENT_INIT_PTR( ( &( pxNewTCB->xNewLib_reent ) ) );
+        /* Initialise this task's Newlib reent structure. */
+        esp_reent_init(&pxNewTCB->xNewLib_reent);
 	}
 	#endif
 
@@ -3643,8 +3644,6 @@ BaseType_t xTaskGetAffinity( TaskHandle_t xTask )
 
 #if ( INCLUDE_vTaskDelete == 1 )
 
-	// TODO: move this to newlib component and provide a header file
-	extern void _extra_cleanup_r(struct _reent* r);
 
 	static void prvDeleteTCB( TCB_t *pxTCB )
 	{
@@ -3657,7 +3656,6 @@ BaseType_t xTaskGetAffinity( TaskHandle_t xTask )
 		to the task to free any memory allocated at the application level. */
 		#if ( configUSE_NEWLIB_REENTRANT == 1 )
 		{
-			pxTCB->xNewLib_reent.__cleanup = &_extra_cleanup_r;
 			_reclaim_reent( &( pxTCB->xNewLib_reent ) );
 		}
 		#endif /* configUSE_NEWLIB_REENTRANT */

components/newlib/platform_include/esp_newlib.h

@@ -15,6 +15,16 @@
 #ifndef __ESP_NEWLIB_H__
 #define __ESP_NEWLIB_H__
 
+#include <sys/reent.h>
+
+/**
+ * Replacement for newlib's _REENT_INIT_PTR and __sinit.
+ *
+ * Called from startup code and FreeRTOS, not intended to be called from
+ * application code.
+ */
+void esp_reent_init(struct _reent* r);
+
 /**
  * Function which sets up syscall table used by newlib functions in ROM.
  *

components/newlib/reent_init.c

@@ -0,0 +1,45 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string.h>
+#include <sys/reent.h>
+#include "esp_attr.h"
+
+/* This function is not part on newlib API, it is defined in libc/stdio/local.h
+ * There is no nice way to get __cleanup member populated while avoiding __sinit,
+ * so extern declaration is used here.
+ */
+extern void _cleanup_r(struct _reent* r);
+
+/**
+ * This is the replacement for newlib's _REENT_INIT_PTR and __sinit.
+ * The problem with __sinit is that it allocates three FILE structures
+ * (stdin, stdout, stderr). Having individual standard streams for each task
+ * is a bit too much on a small embedded system. So we point streams
+ * to the streams of the global struct _reent, which are initialized in
+ * startup code.
+ */
+void IRAM_ATTR esp_reent_init(struct _reent* r)
+{
+    memset(r, 0, sizeof(*r));
+    r->_stdout = _GLOBAL_REENT->_stdout;
+    r->_stderr = _GLOBAL_REENT->_stderr;
+    r->_stdin  = _GLOBAL_REENT->_stdin;
+    r->__cleanup = &_cleanup_r;
+    r->__sdidinit = 1;
+    r->__sglue._next = NULL;
+    r->__sglue._niobs = 0;
+    r->__sglue._iobs = NULL;
+    r->_current_locale = "C";
+}