General tidy up of SH files.

git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@966 1d2547de-c912-0410-9cb9-b8ca96c0e9e2

diff --git a/Source/portable/Renesas/SH2A_FPU/port.c b/Source/portable/Renesas/SH2A_FPU/port.c
index c52485c8169ae1cb327ded740db0b6dbc23f3e4d..7ce291939c3a14b446ec696741fb274c3db18907 100644 (file)
--- a/Source/portable/Renesas/SH2A_FPU/port.c
+++ b/Source/portable/Renesas/SH2A_FPU/port.c
@@ -62,9 +62,14 @@
 /* Library includes. */\r
 #include "string.h"\r
 \r
-#define portINITIAL_SR                 0UL /* No interrupts masked. */\r
+/*-----------------------------------------------------------*/\r
+\r
+/* The SR assigned to a newly created task.  The only important thing in this\r
+value is for all interrupts to be enabled. */\r
+#define portINITIAL_SR                         ( 0UL )\r
 \r
-/* Allocate enough space for FPR0 to FPR15, FPUL and FPSCR, each of which is 4\r
+/* Dimensions the array into which the floating point context is saved.  \r
+Allocate enough space for FPR0 to FPR15, FPUL and FPSCR, each of which is 4\r
 bytes big.  If this number is changed then the 72 in portasm.src also needs\r
 changing. */\r
 #define portFLOP_REGISTERS_TO_STORE    ( 18 )\r
@@ -72,11 +77,6 @@ changing. */
 \r
 /*-----------------------------------------------------------*/\r
 \r
-/*\r
- * Setup a peripheral timer to generate the RTOS tick interrupt.\r
- */\r
-static void prvSetupTimerInterrupt( void );\r
-\r
 /*\r
  * The TRAPA handler used to force a context switch.\r
  */\r
@@ -200,10 +200,18 @@ pxTopOfStack--;
 \r
 portBASE_TYPE xPortStartScheduler( void )\r
 {\r
-       /* Start the tick interrupt. */\r
-       prvSetupTimerInterrupt();\r
-       \r
-       /* Start the first task. */\r
+extern void vApplicationSetupTimerInterrupt( void );\r
+\r
+       /* Call an application function to set up the timer that will generate the\r
+       tick interrupt.  This way the application can decide which peripheral to \r
+       use.  A demo application is provided to show a suitable example. */\r
+       vApplicationSetupTimerInterrupt();\r
+\r
+       /* Start the first task.  This will only restore the standard registers and\r
+       not the flop registers.  This does not really matter though because the only\r
+       flop register that is initialised to a particular value is fpscr, and it is\r
+       only initialised to the current value, which will still be the current value\r
+       when the first task starts executing. */\r
        trapa( portSTART_SCHEDULER_TRAP_NO );\r
 \r
        /* Should not get here. */\r
@@ -217,30 +225,12 @@ void vPortEndScheduler( void )
 }\r
 /*-----------------------------------------------------------*/\r
 \r
-void vPortTickInterrupt( void )\r
-{\r
-       vTaskIncrementTick();\r
-       #if configUSE_PREEMPTION == 1\r
-               vTaskSwitchContext();\r
-       #endif\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
-static void prvSetupTimerInterrupt( void )\r
-{\r
-extern void vApplicationSetupTimerInterrupt( void );\r
-\r
-       /* Call an application function to set up the timer.  This way the application\r
-       can decide which peripheral to use.  A demo application is provided to show a\r
-       suitable example. */\r
-       vApplicationSetupTimerInterrupt();\r
-}\r
-/*-----------------------------------------------------------*/\r
-\r
 void vPortYield( void )\r
 {\r
 long lInterruptMask;\r
 \r
+       /* Ensure the yield trap runs at the same priority as the other interrupts\r
+       that can cause a context switch. */\r
        lInterruptMask = get_imask();\r
 \r
        /* taskYIELD() can only be called from a task, not an interrupt, so the\r
@@ -250,6 +240,8 @@ long lInterruptMask;
        \r
        trapa( portYIELD_TRAP_NO );\r
        \r
+       /* Restore the interrupt mask to whatever it was previously (when the\r
+       function was entered. */\r
        set_imask( ( int ) lInterruptMask );\r
 }\r
 /*-----------------------------------------------------------*/\r
@@ -260,9 +252,15 @@ unsigned long *pulFlopBuffer;
 portBASE_TYPE xReturn;\r
 extern void * volatile pxCurrentTCB;\r
 \r
+       /* This function tells the kernel that the task referenced by xTask is\r
+       going to use the floating point registers and therefore requires the\r
+       floating point registers saved as part of its context. */\r
+\r
+       /* Passing NULL as xTask is used to indicate that the calling task is the\r
+       subject task - so pxCurrentTCB is the task handle. */\r
        if( xTask == NULL )\r
        {\r
-               xTask = pxCurrentTCB;\r
+               xTask = ( xTaskHandle ) pxCurrentTCB;\r
        }\r
 \r
        /* Allocate a buffer large enough to hold all the flop registers. */\r
@@ -270,12 +268,15 @@ extern void * volatile pxCurrentTCB;
        \r
        if( pulFlopBuffer != NULL )\r
        {\r
+               /* Start with the registers in a benign state. */\r
                memset( ( void * ) pulFlopBuffer, 0x00, portFLOP_STORAGE_SIZE );\r
                \r
+               /* The first thing to get saved in the buffer is the FPSCR value -\r
+               initialise this to the current FPSCR value. */\r
                *pulFlopBuffer = get_fpscr();\r
                \r
-               /* Use the task tag to point to the flop buffer.  Pass pointer to just above\r
-               the buffer because the flop save routine uses a pre-decrement. */\r
+               /* Use the task tag to point to the flop buffer.  Pass pointer to just \r
+               above the buffer because the flop save routine uses a pre-decrement. */\r
                vTaskSetApplicationTaskTag( xTask, ( void * ) ( pulFlopBuffer + portFLOP_REGISTERS_TO_STORE ) );                \r
                xReturn = pdPASS;\r
        }\r

diff --git a/Source/portable/Renesas/SH2A_FPU/portmacro.h b/Source/portable/Renesas/SH2A_FPU/portmacro.h
index ca59d72db49f07ebef8e4ecfbdeff2a61d435f14..93c64d96b6b5059d6ac5b2f112d0901121a1e271 100644 (file)
--- a/Source/portable/Renesas/SH2A_FPU/portmacro.h
+++ b/Source/portable/Renesas/SH2A_FPU/portmacro.h
@@ -71,7 +71,8 @@ extern "C" {
  *-----------------------------------------------------------\r
  */\r
 \r
-/* Type definitions. */\r
+/* Type definitions - these are a bit legacy and not really used now, other than\r
+portSTACK_TYPE and portBASE_TYPE. */\r
 #define portCHAR               char\r
 #define portFLOAT              float\r
 #define portDOUBLE             double\r
@@ -90,7 +91,7 @@ extern "C" {
 /*-----------------------------------------------------------*/\r
 \r
 /* Hardware specifics. */\r
-#define portBYTE_ALIGNMENT                             4\r
+#define portBYTE_ALIGNMENT                             8\r
 #define portSTACK_GROWTH                               -1\r
 #define portTICK_RATE_MS                               ( ( portTickType ) 1000 / configTICK_RATE_HZ )          \r
 #define portNOP()                                              nop()\r
@@ -101,19 +102,39 @@ extern "C" {
 void vPortYield( void );\r
 #define portYIELD()                                            vPortYield()\r
 \r
+/* \r
+ * This function tells the kernel that the task referenced by xTask is going to \r
+ * use the floating point registers and therefore requires the floating point \r
+ * registers saved as part of its context. \r
+ */\r
 portBASE_TYPE xPortUsesFloatingPoint( void* xTask );\r
+\r
+/*\r
+ * The flop save and restore functions are defined in portasm.src and called by\r
+ * the trace "task switched in" and "trace task switched out" macros. \r
+ */\r
 void vPortSaveFlopRegisters( void *pulBuffer );\r
 void vPortRestoreFlopRegisters( void *pulBuffer );\r
+\r
+/*\r
+ * pxTaskTag is used to point to the buffer into which the floating point \r
+ * context should be saved.  If pxTaskTag is NULL then the task does not use\r
+ * a floating point context.\r
+ */\r
 #define traceTASK_SWITCHED_OUT() if( pxCurrentTCB->pxTaskTag != NULL ) vPortSaveFlopRegisters( pxCurrentTCB->pxTaskTag )\r
 #define traceTASK_SWITCHED_IN() if( pxCurrentTCB->pxTaskTag != NULL ) vPortRestoreFlopRegisters( pxCurrentTCB->pxTaskTag )\r
 \r
-/*-----------------------------------------------------------*/\r
-\r
+/*\r
+ * These macros should be called directly, but through the taskENTER_CRITICAL()\r
+ * and taskEXIT_CRITICAL() macros.\r
+ */\r
 #define portENABLE_INTERRUPTS()        set_imask( 0x00 )\r
 #define portDISABLE_INTERRUPTS()       set_imask( portKERNEL_INTERRUPT_PRIORITY )\r
 \r
-/* Critical section handling. */\r
+/* Critical nesting counts are stored in the TCB. */\r
 #define portCRITICAL_NESTING_IN_TCB ( 1 )\r
+\r
+/* The critical nesting functions defined within tasks.c. */\r
 extern void vTaskEnterCritical( void );\r
 extern void vTaskExitCritical( void );\r
 #define portENTER_CRITICAL()   vTaskEnterCritical();\r