libff13: enable reentrancy

glue functions for handling the locking are implement as weak symbols in
libff13 itself and overriden to use FreeRTOS's semaphores in epicardium

epicardium/cdcacm.c

@@ -67,7 +67,8 @@
 #define TOSTRING(x) STRINGIFY(x)
 
 /***** Global Data *****/
-volatile int configured;
+//SWYM: rename to CDC_xy or put into struct CDC_state
+volatile int configured; //SWYM: actually unused...
 volatile int suspended;
 volatile unsigned int event_flags;
 int remote_wake_en;

epicardium/fatfs.c

+/*
+ * support routines for FatFs
+ */
+
+#include <stddef.h> //NULL
+#include <stdio.h>
+#include <stdbool.h>
+#include <ff.h>
+
+#include <FreeRTOS.h>
+#include <semphr.h>
+
+static bool mount(void);
+
+
+DIR dir;
+FATFS FatFs;
+
+static volatile struct {
+	bool initiaized;
+}s_state = {
+	.initiaized = false,
+};
+
+bool mount()
+{
+    FRESULT res;
+    res = f_mount(&FatFs,"/",0);
+    if(res != FR_OK) {
+        printf("f_mount error %d\n", res);
+        return false;
+    }
+
+    res = f_opendir(&dir, "0:");
+    if(res != FR_OK) {
+        printf("f_opendir error %d\n", res);
+        return false;
+    }
+
+    return true;
+}
+
+void fatfs_init() {
+	if(mount()) {
+		s_state.initiaized = true;
+		printf("FatFs mounted\n");
+	}
+}
+
+int ff_cre_syncobj (	/* 1:Function succeeded, 0:Could not create the sync object */
+	BYTE vol,			/* Corresponding volume (logical drive number) */
+	FF_SYNC_t *sobj		/* Pointer to return the created sync object */
+)
+{
+	*sobj = xSemaphoreCreateMutex();
+	return (int)(*sobj != NULL);
+
+}
+
+
+/*------------------------------------------------------------------------*/
+/* Delete a Synchronization Object                                        */
+/*------------------------------------------------------------------------*/
+/* This function is called in f_mount() function to delete a synchronization
+/  object that created with ff_cre_syncobj() function. When a 0 is returned,
+/  the f_mount() function fails with FR_INT_ERR.
+*/
+
+int ff_del_syncobj (	/* 1:Function succeeded, 0:Could not delete due to an error */
+	FF_SYNC_t sobj		/* Sync object tied to the logical drive to be deleted */
+)
+{
+	printf("%s\n", __PRETTY_FUNCTION__);
+	/* FreeRTOS */
+    vSemaphoreDelete(sobj);
+	return 1;
+
+}
+
+
+/*------------------------------------------------------------------------*/
+/* Request Grant to Access the Volume                                     */
+/*------------------------------------------------------------------------*/
+/* This function is called on entering file functions to lock the volume.
+/  When a 0 is returned, the file function fails with FR_TIMEOUT.
+*/
+
+int ff_req_grant (	/* 1:Got a grant to access the volume, 0:Could not get a grant */
+	FF_SYNC_t sobj	/* Sync object to wait */
+)
+{
+	/* FreeRTOS */
+	return (int)(xSemaphoreTake(sobj, FF_FS_TIMEOUT) == pdTRUE);
+}
+
+
+/*------------------------------------------------------------------------*/
+/* Release Grant to Access the Volume                                     */
+/*------------------------------------------------------------------------*/
+/* This function is called on leaving file functions to unlock the volume.
+*/
+
+void ff_rel_grant (
+	FF_SYNC_t sobj	/* Sync object to be signaled */
+)
+{
+	/* FreeRTOS */
+	xSemaphoreGive(sobj);
+}

epicardium/main.c

@@ -4,6 +4,7 @@
 #include "max32665.h"
 #include "uart.h"
 #include "cdcacm.h"
+#include "fatfs.h"
 
 #include "card10.h"
 #include "pmic.h"
@@ -45,6 +46,7 @@ int main(void)
 	SCB->SCR |= SCB_SCR_SEVONPEND_Msk;
 
 	cdcacm_init();
+	fatfs_init();
 
 	printf("=> Initializing tasks ...\n");
 

epicardium/meson.build

@@ -67,10 +67,11 @@ subdir('modules/')
 elf = executable(
   name + '.elf',
   'cdcacm.c',
+  'fatfs.c',
   'main.c',
   'support.c',
   module_sources,
-  dependencies: [libcard10, max32665_startup_core0, maxusb],
+  dependencies: [libcard10, max32665_startup_core0, maxusb, libff13],
   link_with: [api_dispatcher_lib, freertos],
   link_whole: [max32665_startup_core0_lib, board_card10_lib],
   include_directories: [freertos_includes],

lib/ff13/Source/ff.h

@@ -311,10 +311,10 @@ void ff_memfree (void* mblock);			/* Free memory block */
 
 /* Sync functions */
 #if FF_FS_REENTRANT
-int ff_cre_syncobj (BYTE vol, FF_SYNC_t* sobj);	/* Create a sync object */
-int ff_req_grant (FF_SYNC_t sobj);		/* Lock sync object */
-void ff_rel_grant (FF_SYNC_t sobj);		/* Unlock sync object */
-int ff_del_syncobj (FF_SYNC_t sobj);	/* Delete a sync object */
+int ff_cre_syncobj (BYTE vol, FF_SYNC_t* sobj) __attribute__((weak));	/* Create a sync object */
+int ff_req_grant (FF_SYNC_t sobj) __attribute__((weak));		/* Lock sync object */
+void ff_rel_grant (FF_SYNC_t sobj) __attribute__((weak));		/* Unlock sync object */
+int ff_del_syncobj (FF_SYNC_t sobj) __attribute__((weak));	/* Delete a sync object */
 #endif
 
 

lib/ff13/Source/ffconf.h

@@ -248,9 +248,11 @@
 /      lock control is independent of re-entrancy. */
 
 
-#define FF_FS_REENTRANT	0
+#define FF_FS_REENTRANT	1
 #define FF_FS_TIMEOUT	1000
-#define FF_SYNC_t		HANDLE
+//in FreeRTOS, SemaphoreHandle_t is a typedef for QueueHandle_t, which is just a typedef for:
+#define FF_SYNC_t		struct QueueDefinition *
+
 /* The option FF_FS_REENTRANT switches the re-entrancy (thread safe) of the FatFs
 /  module itself. Note that regardless of this option, file access to different
 /  volume is always re-entrant and volume control functions, f_mount(), f_mkfs()

lib/ff13/Source/ffsystem.c

@@ -39,6 +39,10 @@ void ff_memfree (
 
 #if FF_FS_REENTRANT	/* Mutal exclusion */
 
+/* we're providing a dummy implementation here, these functions
+ * are to be overridden in the main application (see ffsupport.c)
+ */
+
 /*------------------------------------------------------------------------*/
 /* Create a Synchronization Object */
 /*------------------------------------------------------------------------*/
@@ -47,35 +51,16 @@ void ff_memfree (
 /  When a 0 is returned, the f_mount() function fails with FR_INT_ERR.
 */
 
-//const osMutexDef_t Mutex[FF_VOLUMES];	/* CMSIS-RTOS */
-
+static int s_notAMutex;
 
 int ff_cre_syncobj (	/* 1:Function succeeded, 0:Could not create the sync object */
 	BYTE vol,			/* Corresponding volume (logical drive number) */
 	FF_SYNC_t *sobj		/* Pointer to return the created sync object */
 )
 {
-	/* Win32 */
-	*sobj = CreateMutex(NULL, FALSE, NULL);
-	return (int)(*sobj != INVALID_HANDLE_VALUE);
-
-	/* uITRON */
-//	T_CSEM csem = {TA_TPRI,1,1};
-//	*sobj = acre_sem(&csem);
-//	return (int)(*sobj > 0);
-
-	/* uC/OS-II */
-//	OS_ERR err;
-//	*sobj = OSMutexCreate(0, &err);
-//	return (int)(err == OS_NO_ERR);
-
-	/* FreeRTOS */
-//	*sobj = xSemaphoreCreateMutex();
-//	return (int)(*sobj != NULL);
-
-	/* CMSIS-RTOS */
-//	*sobj = osMutexCreate(Mutex + vol);
-//	return (int)(*sobj != NULL);
+	(void) vol;
+	*sobj = (FF_SYNC_t)&s_notAMutex;
+	return 1;
 }
 
 
@@ -91,23 +76,8 @@ int ff_del_syncobj (	/* 1:Function succeeded, 0:Could not delete due to an error
 	FF_SYNC_t sobj		/* Sync object tied to the logical drive to be deleted */
 )
 {
-	/* Win32 */
-	return (int)CloseHandle(sobj);
-
-	/* uITRON */
-//	return (int)(del_sem(sobj) == E_OK);
-
-	/* uC/OS-II */
-//	OS_ERR err;
-//	OSMutexDel(sobj, OS_DEL_ALWAYS, &err);
-//	return (int)(err == OS_NO_ERR);
-
-	/* FreeRTOS */
-//  vSemaphoreDelete(sobj);
-//	return 1;
-
-	/* CMSIS-RTOS */
-//	return (int)(osMutexDelete(sobj) == osOK);
+	(void) sobj;
+	return 1;
 }
 
 
@@ -122,22 +92,8 @@ int ff_req_grant (	/* 1:Got a grant to access the volume, 0:Could not get a gran
 	FF_SYNC_t sobj	/* Sync object to wait */
 )
 {
-	/* Win32 */
-	return (int)(WaitForSingleObject(sobj, FF_FS_TIMEOUT) == WAIT_OBJECT_0);
-
-	/* uITRON */
-//	return (int)(wai_sem(sobj) == E_OK);
-
-	/* uC/OS-II */
-//	OS_ERR err;
-//	OSMutexPend(sobj, FF_FS_TIMEOUT, &err));
-//	return (int)(err == OS_NO_ERR);
-
-	/* FreeRTOS */
-//	return (int)(xSemaphoreTake(sobj, FF_FS_TIMEOUT) == pdTRUE);
-
-	/* CMSIS-RTOS */
-//	return (int)(osMutexWait(sobj, FF_FS_TIMEOUT) == osOK);
+	(void) sobj;
+	return 1;
 }
 
 
@@ -151,20 +107,7 @@ void ff_rel_grant (
 	FF_SYNC_t sobj	/* Sync object to be signaled */
 )
 {
-	/* Win32 */
-	ReleaseMutex(sobj);
-
-	/* uITRON */
-//	sig_sem(sobj);
-
-	/* uC/OS-II */
-//	OSMutexPost(sobj);
-
-	/* FreeRTOS */
-//	xSemaphoreGive(sobj);
-
-	/* CMSIS-RTOS */
-//	osMutexRelease(sobj);
+	(void) sobj;
 }
 
 #endif