arch/armv6-m: By default, add REG_EXC_RETURN to xcptcontext.

Signed-off-by: wangming9 <wangming9@xiaomi.com>

arch/arm/include/armv6-m/irq.h

@@ -69,17 +69,8 @@
 #define REG_R9              (7)  /* R9 */
 #define REG_R10             (8)  /* R10 */
 #define REG_R11             (9)  /* R11 */
-
-/* In the kernel build, we may return to either privileged or unprivileged
- * modes.
- */
-
-#ifdef CONFIG_BUILD_PROTECTED
-#  define REG_EXC_RETURN    (10) /* EXC_RETURN */
-#  define SW_XCPT_REGS      (11)
-#else
-#  define SW_XCPT_REGS      (10)
-#endif
+#define REG_EXC_RETURN      (10) /* EXC_RETURN */
+#define SW_XCPT_REGS        (11)
 
 /* The total number of registers saved by software */
 

arch/arm/src/armv6-m/arm_exception.S

@@ -114,7 +114,6 @@ exception_common:
 	 * the context is on the MSP or PSP.
 	 */
 
-#ifdef CONFIG_BUILD_PROTECTED
 	mov		r0, r14					/* Copy high register to low register */
 	lsls		r0, #(31 - EXC_RETURN_PROCESS_BITNO)	/* Move to bit 31 */
 	bmi		1f					/* Test bit 31 */
@@ -123,9 +122,6 @@ exception_common:
 
 1:
 	mrs		r1, psp					/* R1=The process stack pointer */
-#else
-	mrs		r1, msp					/* R1=The main stack pointer */
-#endif
 
 	/* R1 is the current stack pointer.  HW_XCPT_REGS were pushed onto the stack
 	 * when the interrupt was taken so (R1)+HW_XCPT_SIZE is the value of the
@@ -151,12 +147,8 @@ exception_common:
 	mov		r3, r9
 	mov		r4, r10
 	mov		r5, r11
-#ifdef CONFIG_BUILD_PROTECTED
 	mov		r6, r14
 	stmia		r0!, {r2-r6}				/* Save the high registers r8-r11 and r14 */
-#else
-	stmia		r0!, {r2-r5}				/* Save the high registers r8-r11 */
-#endif
 
 	/* Get the exception number in R0=IRQ, R1=register save area on stack */
 
@@ -196,20 +188,12 @@ exception_common:
 
 	movs		r2, #(4*REG_R8)				/* R2=Offset to R8 storage */
 	adds		r1, r0, r2				/* R1=Address of R8 storage */
-#ifdef CONFIG_BUILD_PROTECTED
 	ldmia		r1!, {r2-r6}				/* Recover R8-R11 and R14 (5 registers)*/
 	mov		r8, r2					/* Move to position in high registers */
 	mov		r9, r3
 	mov		r10, r4
 	mov		r11, r5
 	mov		r14, r6					/* EXEC_RETURN */
-#else
-	ldmia		r1!, {r2-r5}				/* Recover R8-R11 (4 registers)*/
-	mov		r8, r2					/* Move to position in high registers */
-	mov		r9, r3
-	mov		r10, r4
-	mov		r11, r5
-#endif
 
 	/* Recover SP (R2), PRIMASK (R3), and R4-R7. Determine the value of
 	 * the stack pointer as it was on entry to the exception handler.
@@ -223,7 +207,6 @@ exception_common:
 	 * context is on the MSP or PSP.
 	 */
 
-#ifdef CONFIG_BUILD_PROTECTED
 	mov		r0, r14					/* Copy high register to low register */
 	lsls		r0, #(31 - EXC_RETURN_PROCESS_BITNO)	/* Move to bit 31 */
 	bmi		3f					/* Test bit 31 */
@@ -234,11 +217,6 @@ exception_common:
 	msr		psp, r1					/* R1=The process stack pointer */
 
 4:
-#else
-	msr		msp, r1					/* R1=The main stack pointer */
-	ldr		r0, =EXC_RETURN_PRIVTHR			/* R0=EXC_RETURN to privileged mode */
-	mov		r14, r0					/* R14=EXC_RETURN to privileged mode */
-#endif
 
 	/* Restore the interrupt state */
 

arch/arm/src/armv6-m/arm_initialstate.c

@@ -129,7 +129,6 @@ void up_initial_state(struct tcb_s *tcb)
 #endif
 #endif /* CONFIG_PIC */
 
-#ifdef CONFIG_BUILD_PROTECTED
   /* All tasks start via a stub function in kernel space.  So all
    * tasks must start in privileged thread mode.  If CONFIG_BUILD_PROTECTED
    * is defined, then that stub function will switch to unprivileged
@@ -137,7 +136,6 @@ void up_initial_state(struct tcb_s *tcb)
    */
 
   xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR;
-#endif
 
   /* Enable or disable interrupts, based on user configuration */
 

arch/arm/src/armv6-m/arm_saveusercontext.S

@@ -92,14 +92,12 @@ up_saveusercontext:
 	/* Save r11 and EXC_RETURN */
 
 	mov		r1, r11
-#ifdef CONFIG_BUILD_PROTECTED
+
 	/* Save EXC_RETURN to 0xffffffff */
 
-	movs		r2, #-1
+	movs		r2, #0
+	subs		r2, #1
 	stmia		r0!, {r1-r2}
-#else
-	stmia		r0!, {r1}
-#endif
 
 	movs		r0, #0
 	bx		lr

arch/arm/src/armv6-m/arm_svcall.c

@@ -138,13 +138,8 @@ int arm_svcall(int irq, void *context, void *arg)
       svcinfo("  R8: %08x %08x %08x %08x %08x %08x %08x %08x\n",
               regs[REG_R8],  regs[REG_R9],  regs[REG_R10], regs[REG_R11],
               regs[REG_R12], regs[REG_R13], regs[REG_R14], regs[REG_R15]);
-#  ifdef CONFIG_BUILD_PROTECTED
       svcinfo(" PSR: %08x PRIMASK: %08x EXC_RETURN: %08x\n",
               regs[REG_XPSR], regs[REG_PRIMASK], regs[REG_EXC_RETURN]);
-#  else
-      svcinfo(" PSR: %08x PRIMASK: %08x\n",
-              regs[REG_XPSR], regs[REG_PRIMASK]);
-#  endif
     }
 #endif
 
@@ -446,14 +441,9 @@ int arm_svcall(int irq, void *context, void *arg)
               CURRENT_REGS[REG_R10], CURRENT_REGS[REG_R11],
               CURRENT_REGS[REG_R12], CURRENT_REGS[REG_R13],
               CURRENT_REGS[REG_R14], CURRENT_REGS[REG_R15]);
-#  ifdef CONFIG_BUILD_PROTECTED
       svcinfo(" PSR: %08x PRIMASK: %08x EXC_RETURN: %08x\n",
               CURRENT_REGS[REG_XPSR], CURRENT_REGS[REG_PRIMASK],
               CURRENT_REGS[REG_EXC_RETURN]);
-#  else
-      svcinfo(" PSR: %08x PRIMASK: %08x\n",
-              CURRENT_REGS[REG_XPSR], CURRENT_REGS[REG_PRIMASK]);
-#  endif
     }
 #  ifdef CONFIG_DEBUG_SVCALL
   else