More Cortex-M0 fixes

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5671 42af7a65-404d-4744-a932-0658087f49c3

6 files changed, 65 insertions, 10 deletions

diff --git a/nuttx/arch/arm/include/armv6-m/irq.h b/nuttx/arch/arm/include/armv6-m/irq.h
index bad7883fa..68f8c75d4 100644
--- a/nuttx/arch/arm/include/armv6-m/irq.h
+++ b/nuttx/arch/arm/include/armv6-m/irq.h
@@ -74,11 +74,20 @@
 #define REG_R9              (7)  /* R9 */
 #define REG_R10             (8)  /* R10 */
 #define REG_R11             (9)  /* R11 */
-#define REG_EXC_RETURN      (10) /* EXC_RETURN */
+
+/* In the kernel build, we may return to either privileged or unprivileged
+ * modes.
+ */
+
+#ifdef CONFIG_NUTTX_KERNEL
+#  define REG_EXC_RETURN    (10) /* EXC_RETURN */
+#  define SW_XCPT_REGS      (11)
+#else
+#  define SW_XCPT_REGS      (10)
+#endif
 
 /* The total number of registers saved by software */
 
-#define SW_XCPT_REGS        (11)
 #define SW_XCPT_SIZE        (4 * SW_XCPT_REGS)
 
 /* On entry into an IRQ, the hardware automatically saves the following
diff --git a/nuttx/arch/arm/src/armv6-m/up_assert.c b/nuttx/arch/arm/src/armv6-m/up_assert.c
index f2a18c28b..15ba1f53f 100644
--- a/nuttx/arch/arm/src/armv6-m/up_assert.c
+++ b/nuttx/arch/arm/src/armv6-m/up_assert.c
@@ -147,8 +147,14 @@ static inline void up_registerdump(void)
             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_NUTTX_KERNEL
+      lldbg("xPSR: %08x BASEPRI: %08x EXEC_RETURN: %08x\n",
+            current_regs[REG_XPSR], current_regs[REG_BASEPRI],
+            current_regs[REG_EXC_RETURN]);
+#else
       lldbg("xPSR: %08x BASEPRI: %08x\n",
-            current_regs[REG_XPSR],  current_regs[REG_BASEPRI]);
+            current_regs[REG_XPSR], current_regs[REG_BASEPRI]);
+#endif
     }
 }
 #else
diff --git a/nuttx/arch/arm/src/armv6-m/up_exception.S b/nuttx/arch/arm/src/armv6-m/up_exception.S
index 6a74d4dd6..d442a28b7 100644
--- a/nuttx/arch/arm/src/armv6-m/up_exception.S
+++ b/nuttx/arch/arm/src/armv6-m/up_exception.S
@@ -92,6 +92,7 @@ exception_common:
 	 * the context is on the MSP or PSP.
 	 */
 
+#ifdef CONFIG_NUTTX_KERNEL
 	mov		r0, r14					/* Copy high register to low register */
 	lsl		r0, #(31 - EXC_RETURN_PROCESS_BITNO)	/* Move to bit 31 */
 	bmi		1f						/* Test bit 31 */
@@ -100,6 +101,9 @@ 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
@@ -125,8 +129,12 @@ exception_common:
 	mov		r3, r9
 	mov		r4, r10
 	mov		r5, r11
+#ifdef CONFIG_NUTTX_KERNEL
 	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 */
 
@@ -170,10 +178,10 @@ exception_common:
 
 	/* Copy the hardware-saved context to the new stack */
 
-	mov		r2, #SW_XCPT_SIZE		/* R2=Size of sofware-saved portion of the context array */
+	mov		r2, #SW_XCPT_SIZE		/* R2=Size of software-saved portion of the context array */
 	add		r1, r0, r2				/* R1=Address of HW save area in reg array */
-	ldr		r2, [r0, #(4*REG_SP)]	/* R1=Value of SP before interrupt */
-	sub		r2, #HW_XCPT_SIZE		/* R1=Address of HW save area on stack */
+	ldr		r2, [r0, #(4*REG_SP)]	/* R2=Value of SP before the interrupt */
+	sub		r2, #HW_XCPT_SIZE		/* R2=Address of HW save area on the return stack */
 	ldmia	r1!, {r4-r7}			/* Fetch four registers from the HW save area */
 	stmia	r2!, {r4-r7}			/* Copy four registers to the return stack */
 	ldmia	r1!, {r4-r7}			/* Fetch four registers from the HW save area */
@@ -192,12 +200,20 @@ exception_common:
 
 	mov		r2, #(4*REG_R8)			/* R2=Offset to R8 storage */
 	add		r0, r1, r2				/* R0=Address of R8 storage */
+#ifdef CONFIG_NUTTX_KERNEL
 	ldmia	r0!, {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	r0!, {r2-r5}			/* 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
+#endif
 
 	/* Recover SP (R2), BASEPRI (R3), and R4-R7. Determine the value of
 	 * the stack pointer as it was on entry to the exception handler.
@@ -211,6 +227,7 @@ exception_common:
 	 * context is on the MSP or PSP.
 	 */
 
+#ifdef CONFIG_NUTTX_KERNEL
 	mov		r0, r14					/* Copy high register to low register */
 	lsl		r0, #(31 - EXC_RETURN_PROCESS_BITNO)	/* Move to bit 31 */
 	bmi		5f						/* Test bit 31 */
@@ -221,6 +238,12 @@ exception_common:
 	msr		psp, r1					/* R1=The process stack pointer */
 
 6:
+#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 */
 
 	msr		basepri, r3				/* Restore interrupts priority masking*/
diff --git a/nuttx/arch/arm/src/armv6-m/up_initialstate.c b/nuttx/arch/arm/src/armv6-m/up_initialstate.c
index ccb924ebe..3e7e3a48f 100644
--- a/nuttx/arch/arm/src/armv6-m/up_initialstate.c
+++ b/nuttx/arch/arm/src/armv6-m/up_initialstate.c
@@ -138,7 +138,6 @@ void up_initial_state(struct tcb_s *tcb)
       xcp->regs[REG_EXC_RETURN] = EXC_RETURN_UNPRIVTHR;
     }
   else
-#endif /* CONFIG_NUTTX_KERNEL */
     {
       /* If the kernel build is not selected -OR- if this is a kernel
        * thread, then start it in privileged thread mode.
@@ -146,6 +145,7 @@ void up_initial_state(struct tcb_s *tcb)
 
       xcp->regs[REG_EXC_RETURN] = EXC_RETURN_PRIVTHR;
     }
+#endif /* CONFIG_NUTTX_KERNEL */
 
   /* Enable or disable interrupts, based on user configuration */
 
diff --git a/nuttx/arch/arm/src/armv6-m/up_sigdeliver.c b/nuttx/arch/arm/src/armv6-m/up_sigdeliver.c
index a69d64bf4..ca60b68c5 100644
--- a/nuttx/arch/arm/src/armv6-m/up_sigdeliver.c
+++ b/nuttx/arch/arm/src/armv6-m/up_sigdeliver.c
@@ -81,8 +81,13 @@
 
 void up_sigdeliver(void)
 {
+  /* NOTE the "magic" guard space added to regs.  This is a little kludge
+   * because up_fullcontextrestore (called below) will do a stack-to-stack
+   * copy an may overwrite the regs[] array contents.  Sorry.
+   */
+
   struct tcb_s  *rtcb = (struct tcb_s*)g_readytorun.head;
-  uint32_t regs[XCPTCONTEXT_REGS];
+  uint32_t regs[XCPTCONTEXT_REGS + 4];
   sig_deliver_t sigdeliver;
 
   /* Save the errno.  This must be preserved throughout the signal handling
diff --git a/nuttx/arch/arm/src/armv6-m/up_svcall.c b/nuttx/arch/arm/src/armv6-m/up_svcall.c
index c1e35d6ab..60dde4bf5 100644
--- a/nuttx/arch/arm/src/armv6-m/up_svcall.c
+++ b/nuttx/arch/arm/src/armv6-m/up_svcall.c
@@ -249,7 +249,13 @@ int up_svcall(int irq, FAR void *context)
   svcdbg("  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]);
-  svcdbg("  PSR=%08x\n", regs[REG_XPSR]);
+#ifdef CONFIG_NUTTX_KERNEL
+  svcdbg("xPSR: %08x BASEPRI: %08x EXEC_RETURN: %08x\n",
+         regs[REG_XPSR], regs[REG_BASEPRI], regs[REG_EXC_RETURN]);
+#else
+  svcdbg("xPSR: %08x BASEPRI: %08x\n",
+         regs[REG_XPSR], regs[REG_BASEPRI]);
+#endif
 
   /* Handle the SVCall according to the command in R0 */
 
@@ -346,7 +352,13 @@ int up_svcall(int irq, FAR void *context)
       svcdbg("  R8: %08x %08x %08x %08x %08x %08x %08x %08x\n",
              current_regs[REG_R8],  current_regs[REG_R9],  current_regs[REG_R10], current_regs[REG_R11],
              current_regs[REG_R12], current_regs[REG_R13], current_regs[REG_R14], current_regs[REG_R15]);
-      svcdbg("  PSR=%08x\n", current_regs[REG_XPSR]);
+#ifdef CONFIG_NUTTX_KERNEL
+      svcdbg("xPSR: %08x BASEPRI: %08x EXEC_RETURN: %08x\n",
+             current_regs[REG_XPSR], current_regs[REG_BASEPRI], current_regs[REG_EXC_RETURN]);
+#else
+      svcdbg("xPSR: %08x BASEPRI: %08x\n",
+             current_regs[REG_XPSR], current_regs[REG_BASEPRI]);
+#endif
     }
   else
     {