Fix a PIC32 software interrupt bug (pipeline hazard)

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4224 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/arch/mips/include/mips32/irq.h

@@ -2,7 +2,7 @@
  * arch/mips/include/mips32/irq.h
  *
  *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

nuttx/arch/mips/src/common/up_initialize.c

@@ -2,7 +2,7 @@
  * arch/mips/src/common/up_initialize.c
  *
  *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

nuttx/arch/mips/src/common/up_internal.h

@@ -2,7 +2,7 @@
  * arch/mips/common/up_internal.h
  *
  *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -169,6 +169,14 @@ extern void up_copystate(uint32_t *dest, uint32_t *src);
 extern void up_puts(const char *str);
 extern void up_lowputs(const char *str);
 
+/* Defined in drivers/lowconsole.c */
+
+#ifdef CONFIG_DEV_LOWCONSOLE
+extern void lowconsole_init(void);
+#else
+# define lowconsole_init()
+#endif
+
 /* Debug */
 
 #ifdef CONFIG_ARCH_STACKDUMP

nuttx/arch/mips/src/mips32/up_swint0.c

@@ -2,7 +2,7 @@
  * arch/mips/src/mips32/up_swint0.c
  *
  *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

nuttx/arch/mips/src/mips32/up_syscall0.S

@@ -2,7 +2,7 @@
  * arch/mips/src/mips32/up_syscall0.S
  *
  *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -73,6 +73,9 @@
  *   up_syscall2 - System call SYS_ argument and two additional parameters.
  *   up_syscall3 - System call SYS_ argument and three additional parameters.
  *
+ * Assumption:
+ *   All interrupts are disabled except for the software interrupts.
+ *
  ****************************************************************************/
 
 	.text
@@ -85,10 +88,25 @@ sys_call3:	/* r4 holds the syscall number, arguments in r5, r6, and r7 */
 
 	.set	push
 	.set	noat
+
+	/* Set Bit 8 to request the software interrupt */
+
 	mfc0	t3, MIPS32_CP0_CAUSE	/* t3 = CP0 cause register */
 	ori		t3, (1 << 8)			/* Bit 8: Request software interrupt 0 */
 	.set	noreorder
 	mtc0	t3, MIPS32_CP0_CAUSE	/* Trigger the software interrupt */
-	nop								/* Delay slot */
+
-	j		ra						/* Return with result in v0 */
+	/* The actual interrupt will not a occur for a few more cycles.  Let's
+	 * put a few nop's here in hope that the SW interrupt occurs during
+	 * the sequence of nops.
+	 */
+
+	nop
+	nop
+	nop
+	nop
+
+	/* Then return with the result of the software interrupt in v0 */
+
+	j		ra
 	.end	sys_call0

nuttx/configs/pic32-starterkit/README.txt

@@ -54,6 +54,7 @@ Contents
   Powering the Board
   Creating Compatible NuttX HEX files
   Serial Console
+  LEDs
   PIC32MX Configuration Options
   Configurations
 
@@ -596,6 +597,43 @@ Serial Console
        26  3.3V
        28  GND
 
+LEDs
+====
+
+  The PIC32MX Ethernet Starter kit has 3 user LEDs labeled LED1-3 on the
+  board graphics (but referred to as LED4-6 in the schematic):
+
+  PIN  User's Guide   Board Stencil   Notes
+  ---  -------------  --------------  -------------------------
+  RD0  "User LED D4"  "LED1 (RD0")    High illuminates (RED)
+  RD2  "User LED D5"  "LED3 (RD2)"    High illuminates (YELLOW)
+  RD1  "User LED D6"  "LED2 (RD1)"    High illuminates (GREEN)
+
+  We will use the labels on the board to identify LEDs.  If CONFIG_ARCH_LEDS
+  is defined, then NuttX will control these LEDs as follows:
+
+                            ON                  OFF
+  ------------------------- ---- ---- ---- ---- ---- ----
+                            LED1 LED2 LED3 LED1 LED2 LED3
+  ------------------------- ---- ---- ---- ---- ---- ----
+  LED_STARTED            0  OFF  OFF  OFF  ---  ---  ---
+  LED_HEAPALLOCATE       1  ON   OFF  N/C  ---  ---  ---
+  LED_IRQSENABLED        2  OFF  ON   N/C  ---  ---  ---
+  LED_STACKCREATED       3  ON   ON   N/C  ---  ---  ---
+  LED_INIRQ              4  N/C  N/C  ON   N/C  N/C  OFF
+  LED_SIGNAL             4  N/C  N/C  ON   N/C  N/C  OFF
+  LED_ASSERTION          4  N/C  N/C  ON   N/C  N/C  OFF
+  LED_PANIC              5  ON   N/C  N/C  OFF  N/C  N/C
+
+  There are 5 additional LEDs available on the MEB.  These are not
+  used by NuttX.
+
+    RD1          LED1
+    RD2          LED2
+    RD3          LED3
+    RC1          LED4
+    RC2          LED5
+
 PIC32MX Configuration Options
 =============================
 

nuttx/configs/pic32-starterkit/include/board.h

@@ -89,10 +89,10 @@
  * board graphics (but referred to as LED4-6 in the schematic):
  *
  * PIN User's Guide  Board Stencil  Notes
- * --- ------------- -------------- -------------------
+ * --- ------------- -------------- -------------------------
- * RD0 "User LED D4" "LED1 (RD0")   High illuminates
+ * RD0 "User LED D4" "LED1 (RD0")   High illuminates (RED)
- * RD2 "User LED D5" "LED3 (RD2)"   High illuminates
+ * RD2 "User LED D5" "LED3 (RD2)"   High illuminates (YELLOW)
- * RD1 "User LED D6" "LED2 (RD1)"   High illuminates
+ * RD1 "User LED D6" "LED2 (RD1)"   High illuminates (GREEN)
  *
  * We will use the labels on the board to identify LEDs
  *
@@ -107,7 +107,7 @@
  * LED_INIRQ              4  N/C  N/C  ON   N/C  N/C  OFF
  * LED_SIGNAL             4  N/C  N/C  ON   N/C  N/C  OFF
  * LED_ASSERTION          4  N/C  N/C  ON   N/C  N/C  OFF
- * LED_PANIC              4  N/C  N/C  ON   N/C  N/C  OFF
+ * LED_PANIC              5  ON   N/C  N/C  OFF  N/C  N/C
  *
  * There are 5 additional LEDs available on the MEB:
  *
@@ -125,9 +125,9 @@
 #define LED_INIRQ              4
 #define LED_SIGNAL             4
 #define LED_ASSERTION          4
-#define LED_PANIC              4
+#define LED_PANIC              5
 
-#define LED_NVALUES            5
+#define LED_NVALUES            6
 
 /* Switch definitions *******************************************************/
 /* The PIC32 start kit has 3 switches:

nuttx/configs/pic32-starterkit/src/up_leds.c

@@ -64,10 +64,10 @@
  * board graphics (but referred to as LED4-6 in the schematic):
  *
  * PIN User's Guide  Board Stencil  Notes
- * --- ------------- -------------- -------------------
+ * --- ------------- -------------- -------------------------
- * RD0 "User LED D4" "LED1 (RD0")   High illuminates
+ * RD0 "User LED D4" "LED1 (RD0")   High illuminates (RED)
- * RD2 "User LED D5" "LED3 (RD2)"   High illuminates
+ * RD2 "User LED D5" "LED3 (RD2)"   High illuminates (YELLOW)
- * RD1 "User LED D6" "LED2 (RD1)"   High illuminates
+ * RD1 "User LED D6" "LED2 (RD1)"   High illuminates (GREEN)
  *
  * We will use the labels on the board to identify LEDs
  *
@@ -82,7 +82,7 @@
  * LED_INIRQ              4  N/C  N/C  ON   N/C  N/C  OFF
  * LED_SIGNAL             4  N/C  N/C  ON   N/C  N/C  OFF
  * LED_ASSERTION          4  N/C  N/C  ON   N/C  N/C  OFF
- * LED_PANIC              4  N/C  N/C  ON   N/C  N/C  OFF
+ * LED_PANIC              5  ON   N/C  N/C  OFF  N/C  N/C
  */
 
 #define GPIO_LED_1   (GPIO_OUTPUT|GPIO_VALUE_ZERO|GPIO_PORTD|GPIO_PIN0)
@@ -134,6 +134,7 @@ static const struct led_setting_s g_ledonvalues[LED_NVALUES] =
   {LED_OFF, LED_ON,  LED_NC,  LED_OFF},
   {LED_ON,  LED_ON,  LED_NC,  LED_OFF},
   {LED_NC,  LED_NC,  LED_ON,  LED_OFF},
+  {LED_ON,  LED_NC,  LED_NC,  LED_OFF},
 };
 
 static const struct led_setting_s g_ledoffvalues[LED_NVALUES] =
@@ -143,6 +144,7 @@ static const struct led_setting_s g_ledoffvalues[LED_NVALUES] =
   {LED_NC,  LED_NC,  LED_NC,  LED_OFF},
   {LED_NC,  LED_NC,  LED_NC,  LED_OFF}, 
   {LED_NC,  LED_NC,  LED_OFF, LED_OFF},
+  {LED_OFF, LED_NC,  LED_NC,  LED_OFF},
 };
 
 /****************************************************************************