libsecureshield: improve the comments and declartions

Improve the code comments and declartions in freertos port for secureshield
and freertos kernel secure example

Author: wayne ren

example/freertos/kernel_secure/background_container.c

@@ -268,7 +268,7 @@ static void interrupt_high_pri(void *p_excinf)
 
 /**
  * \brief  low priority interrupt
- * \details write AUX_IRQ_HINT to raise higher priority interrtupt.
+ * \details write AUX_IRQ_HINT to raise higher priority interrupt.
  * \param[in] *p_excinf
  */
 static void interrupt_low_pri(void *p_exinf)

example/freertos/kernel_secure/container1.h

@@ -58,8 +58,6 @@ typedef struct {
 
 
 extern uint8_t _f_data_container12_shared[];
-extern uint8_t _e_bss_container12_shared[];
-
 
 extern int32_t init_secret(void);
 extern int32_t operate_secret(char* pwd, uint32_t cmd, char * data);

example/freertos/kernel_secure/container_cfg.c

@@ -41,14 +41,14 @@
 #include "container2.h"
 #include "background_container.h"
 
-// Container 1: two special memory regions for initialization and communication with container 2
+// Container 1:  one special memory region for communication with container 2
 static CONTAINER_AC_TABLE g_container1_act[] = {
 	{init_secret, 0, SECURESHIELD_AC_INTERFACE},
 	{operate_secret, 3, SECURESHIELD_AC_INTERFACE},
 	{(void *)CONTAINER_12_SHARED_ORIGIN, CONTAINER_12_SHARED_LENGTH, SECURESHIELD_ACDEF_URAM}
  };
 
-// Container 2: special memory regions for communication with container 2
+// Container 2: one special memory region for communication with container 2
 static CONTAINER_AC_TABLE g_container2_act[] = {
 	{(void *)CONTAINER_12_SHARED_ORIGIN, CONTAINER_12_SHARED_LENGTH, SECURESHIELD_ACDEF_URAM},
 	{trusted_ops, 0, SECURESHIELD_AC_INTERFACE}
@@ -71,6 +71,7 @@ static CONTAINER_AC_TABLE g_main_container_act[] = {
 	{(void *)0x100, 0x6, SECURESHIELD_AC_AUX},
 	{(void *)0x75, 0x1, SECURESHIELD_AC_AUX},
 #endif	
+/* if LIB_SECURESHIELD_VERSION == 2, the following interrupts are configured as normal interrupts */
 	{default_interrupt_handler, INTNO_LOW_PRI, SECURESHIELD_AC_IRQ},
 	{default_interrupt_handler, INTNO_HIGH_PRI, SECURESHIELD_AC_IRQ},
 	{default_interrupt_handler, INTNO_TIMER0, SECURESHIELD_AC_IRQ}
@@ -79,6 +80,6 @@ static CONTAINER_AC_TABLE g_main_container_act[] = {
 /* enable secureshield, set the access control table of background container */
 SECURESHIELD_SET_MODE_AC(SECURESHIELD_ENABLED, g_main_container_act);
 
-/* configure the other container */
+/* configure other containers */
 SECURESHIELD_CONTAINER_CONFIG(container1, g_container1_act, 1024);
 SECURESHIELD_CONTAINER_CONFIG(container2, g_container2_act, 1024);

example/freertos/kernel_secure/secureshield_appl_config.h

@@ -34,12 +34,14 @@
 #ifndef _SECURESHIELD_APPL_CONFIG_H_
 #define _SECURESHIELD_APPL_CONFIG_H_
 
-/* tell linker script template, there is a region named container1 in normal rom, its size is 2048 bytes */
+/* tell linker script template, there is a region named container1 in normal rom, its size is 2048 bytes 
+ * container2 related definiion is a placeholder to generate necessary symbols */
 #define SECURESHIELD_REGION_CONTAINERS_ROM \
  					GEN_CONTAINER_ROM_SECTION(container1, 2048)	\
  					GEN_CONTAINER_ROM_SECTION(container2, 0)
 
-/* tell linker script template, there is a region named container12 in normal ram, its size is 2048 bytes */
+/* tell linker script template, there are regions named container1, container2 and container12 in normal 
+ * ram who sizes are 2048 bytes */
 #define SECURESHIELD_REGION_CONTAINERS_RAM \
  					GEN_CONTAINER_RAM_SECTION(container1, 2048) \
  					GEN_CONTAINER_RAM_SECTION(container2, 2048) \

os/freertos/portable/Synopsys/ARC/arc_support.s

@@ -112,7 +112,7 @@ dispatch_r:
 	.align 4
 start_dispatch:
 /*
- *  this routine is called in the non-task conext during the startup of the kernel
+ *  this routine is called in the non-task context during the startup of the kernel
  *  , and all the interrupts are locked.
  *
  *  when the dispatcher is called, the cpu is locked, no nest exception (CPU exception/interrupt).
@@ -177,7 +177,7 @@ exc_entry_cpu:
 	st	r1, [exc_nest_count]
 	cmp	r0, 0
 	bne	exc_handler_1
-/* chang to interrupt stack if interrupt happened in task context */
+/* change to exception stack if interrupt happened in task context */
 	mov	sp, _e_stack
 exc_handler_1:
 	PUSH	blink
@@ -268,7 +268,7 @@ exc_entry_int:
 	st	r2, [exc_nest_count]
 	cmp	r3, 0
 	bne	irq_handler_1
-/* chang to interrupt stack if interrupt happened in task context */
+/* change to exception stack if interrupt happened in task context */
 	mov	sp, _e_stack
 irq_handler_1:
 	PUSH	blink
@@ -308,7 +308,7 @@ ret_int_1:	/* return from non-task context */
 	rtie
 /* there is a dispatch request */
 ret_int_2:
-	/* clear dispatch requst */
+	/* clear dispatch request */
 	mov	r0, 0
 	st	r0, [context_switch_reqflg]
 

os/freertos/portable/Synopsys/ARC_EM_SECURESHIELD/arc_freertos_exceptions.h

@@ -1,5 +1,5 @@
 /*
-    FreeRTOS V8.2.3 - Copyright (C) 2015 Real Time Engineers Ltd.
+    FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd.
     All rights reserved
 
     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
@@ -78,9 +78,7 @@ extern void exc_entry_cpu(void);	/* cpu exception entry for freertos */
 extern void exc_entry_int(void);	/* int exception entry for freertos */
 
 /* task dispatch functions in .s */
-extern void start_r(void);
 extern void start_dispatch();
-extern void dispatch();
 
 extern void freertos_exc_init(void);
 

os/freertos/portable/Synopsys/ARC_EM_SECURESHIELD/arc_support.s

@@ -89,10 +89,9 @@
 	.align 4
 start_dispatch:
 /*
- *  this routine is called in the non-task conext during the startup of the kernel
+ *  this routine is called in the non-task context during the startup of the kernel
  *  , and all the interrupts are locked.
  *
- *  when the dispatcher is called, the cpu is locked, no nest exception (CPU exception/interrupt).
  *  In target_initialize, all interrupt priority mask should be cleared, cpu should be
  *  locked, the interrupts outside the kernel such as fiq can be
  *  enabled.
@@ -112,7 +111,7 @@ dispatcher:
 /*
  *  before dispatcher is called, task context | cpu locked | dispatch enabled
  *  should be satisfied. In this routine, the processor will jump
- *  into the entry of next to run task
+ *  into the entry of next to run task through exception return
  *
  *  i.e. kernel mode, IRQ disabled, dispatch enabled
  */
@@ -141,7 +140,7 @@ exc_entry_cpu:
 	st	r1, [exc_nest_count]
 	cmp	r0, 0
 	bne	exc_handler_1
-/* chang to interrupt stack if interrupt happened in task context */
+/* change to exception stack if interrupt happened in task context */
 	mov	sp, _e_stack
 exc_handler_1:
 	PUSH	blink
@@ -188,19 +187,7 @@ ret_exc_r_1:
 exc_entry_int:
 	clri	/* disable interrupt */
 
-#if ARC_FEATURE_FIRQ == 1
-#if ARC_FEATURE_RGF_NUM_BANKS > 1
-	lr	r0, [AUX_IRQ_ACT]			/*  check whether it is P0 interrupt */
-	btst	r0, 0
-	jnz	exc_entry_firq
-#else
-	PUSH	r10
-	lr	r10, [AUX_IRQ_ACT]
-	btst	r10, 0
-	POP	r10
-	jnz	exc_entry_firq
-#endif
-#endif
+	/* FIRQ and banking is not supported now in secureshield */
 	INTERRUPT_PROLOGUE
 
 	mov	blink, sp
@@ -210,7 +197,7 @@ exc_entry_int:
 	st	r2, [exc_nest_count]
 	cmp	r3, 0
 	bne	irq_handler_1
-/* chang to interrupt stack if interrupt happened in task context */
+/* change to exception stack if interrupt happened in task context */
 	mov	sp, _e_stack
 irq_handler_1:
 	PUSH	blink
@@ -242,7 +229,7 @@ ret_int:
 	ld	r0, [context_switch_reqflg]
 	cmp	r0, 0
 	beq	ret_int_r_1
-	/* clear dispatch requst */
+	/* clear dispatch request */
 	mov	r0, 0
 	st	r0, [context_switch_reqflg]
 
@@ -263,6 +250,12 @@ ret_int:
 	st	r0, [ulCriticalNesting]
 	RESTORE_CALLEE_REGS
 ret_int_r_1:
+	/* differences between INTERRUPT_EPILOGUE and EXCEPTION_EPILOGUE:
+	 *  INTERRUPT_EPIOLOGUE is a subset of EXCEPTION_EPIOLOGUE.
+	 *  In EXCEPTION_EPILOGUE, all regs are popped through SW.
+	 *  IN INTERRUPT_EPILOGUE, some regs are popped through SW, the left
+	 *  part is popped by HW (interrupt return).
+	*/
 	INTERRUPT_EPILOGUE
 	rtie
 /** @endcond */

os/freertos/portable/Synopsys/ARC_EM_SECURESHIELD/freertos_tls.c

@@ -1,5 +1,5 @@
 /*
-    FreeRTOS V8.2.3 - Copyright (C) 2015 Real Time Engineers Ltd.
+    FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd.
     All rights reserved
 
     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

os/freertos/portable/Synopsys/ARC_EM_SECURESHIELD/port.c

@@ -121,11 +121,10 @@ static void prvSetupTimerInterrupt(void)
 
 /*
  * Setup the stack of a new task so it is ready to be placed under the
- * scheduler control.  The registers have to be placed on the stack in
+ * scheduler control. The registers have to be placed on the stack in
  * the order that the port expects to find them.
  *
- * For ARC, task context switch is implemented with the help of SWI exception
- * It's not efficient but simple.
+ * For ARC, task context switch is implemented with the help of TRAP exception
  *
  */
 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )