Enabled CCM RAM for stack. Added stack watermarking

Makefile

@@ -506,6 +506,7 @@ COMMON_SRC = \
             drivers/serial.c \
             drivers/serial_uart.c \
             drivers/sound_beeper.c \
+            drivers/stack_check.c \
             drivers/system.c \
             drivers/timer.c \
             fc/config.c \

src/main/build/debug.h

@@ -61,5 +61,6 @@ typedef enum {
     DEBUG_ANGLERATE,
     DEBUG_ESC_TELEMETRY,
     DEBUG_SCHEDULER,
+    DEBUG_STACK,
     DEBUG_COUNT
 } debugType_e;

src/main/drivers/stack_check.c

@@ -0,0 +1,99 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "platform.h"
+
+#include "build/debug.h"
+
+#include "common/utils.h"
+
+#include "drivers/stack_check.h"
+
+#define STACK_FILL_CHAR 0xa5
+
+extern char _estack; // end of stack, declared in .LD file
+extern char _Min_Stack_Size; // declared in .LD file
+
+/*
+ * The ARM processor uses a full descending stack. This means the stack pointer holds the address
+ * of the last stacked item in memory. When the processor pushes a new item onto the stack,
+ * it decrements the stack pointer and then writes the item to the new memory location.
+ *
+ *
+ * RAM layout is generally as below, although some targets vary
+ *
+ * F1 Boards
+ * RAM is origin 0x20000000 length 20K that is:
+ * 0x20000000 to 0x20005000
+ *
+ * F3 Boards
+ * RAM is origin 0x20000000 length 40K that is:
+ * 0x20000000 to 0x2000a000
+ *
+ * F4 Boards
+ * RAM is origin 0x20000000 length 128K that is:
+ * 0x20000000 to 0x20020000
+ *
+ */
+
+#ifdef STACK_CHECK
+
+static uint32_t usedStackSize;
+
+void taskStackCheck(timeUs_t currentTimeUs)
+{
+    UNUSED(currentTimeUs);
+
+    char * const stackHighMem = &_estack;
+    const uint32_t stackSize = (uint32_t)&_Min_Stack_Size;
+    char * const stackLowMem = stackHighMem - stackSize;
+    const char * const stackCurrent = (char *)&stackLowMem;
+
+    char *p;
+    for (p = stackLowMem; p < stackCurrent; ++p) {
+        if (*p != STACK_FILL_CHAR) {
+            break;
+        }
+    }
+
+    usedStackSize = (uint32_t)stackHighMem - (uint32_t)p;
+
+    DEBUG_SET(DEBUG_STACK, 0, (uint32_t)stackHighMem & 0xffff);
+    DEBUG_SET(DEBUG_STACK, 1, (uint32_t)stackLowMem & 0xffff);
+    DEBUG_SET(DEBUG_STACK, 2, (uint32_t)stackCurrent & 0xffff);
+    DEBUG_SET(DEBUG_STACK, 3, (uint32_t)p & 0xffff);
+}
+
+uint32_t stackUsedSize(void)
+{
+    return usedStackSize;
+}
+#endif
+
+uint32_t stackTotalSize(void)
+{
+    return (uint32_t)&_Min_Stack_Size;
+}
+
+uint32_t stackHighMem(void)
+{
+    return (uint32_t)&_estack;
+}

src/main/drivers/stack_check.h

@@ -0,0 +1,25 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "common/time.h"
+
+void taskStackCheck(timeUs_t currentTimeUs);
+uint32_t stackUsedSize(void);
+uint32_t stackTotalSize(void);
+uint32_t stackHighMem(void);

src/main/fc/fc_tasks.c

@@ -31,6 +31,7 @@
 #include "drivers/accgyro.h"
 #include "drivers/compass.h"
 #include "drivers/serial.h"
+#include "drivers/stack_check.h"
 
 #include "fc/config.h"
 #include "fc/fc_msp.h"
@@ -286,6 +287,9 @@ void fcTasksInit(void)
     setTaskEnabled(TASK_CMS, feature(FEATURE_OSD) || feature(FEATURE_DASHBOARD));
 #endif
 #endif
+#ifdef STACK_CHECK
+    setTaskEnabled(TASK_STACK_CHECK, true);
+#endif
 }
 
 cfTask_t cfTasks[TASK_COUNT] = {
@@ -463,4 +467,13 @@ cfTask_t cfTasks[TASK_COUNT] = {
         .staticPriority = TASK_PRIORITY_LOW,
     },
 #endif
+
+#ifdef STACK_CHECK
+    [TASK_STACK_CHECK] = {
+        .taskName = "STACKCHECK",
+        .taskFunc = taskStackCheck,
+        .desiredPeriod = TASK_PERIOD_HZ(10),          // 10 Hz
+        .staticPriority = TASK_PRIORITY_IDLE,
+    },
+#endif
 };

src/main/io/serial_cli.c

@@ -58,6 +58,7 @@ uint8_t cliMode = 0;
 #include "drivers/sdcard.h"
 #include "drivers/buf_writer.h"
 #include "drivers/serial_escserial.h"
+#include "drivers/stack_check.h"
 #include "drivers/vcd.h"
 
 #include "fc/config.h"
@@ -3600,6 +3601,11 @@ static void cliStatus(char *cmdline)
     uint16_t i2cErrorCounter = 0;
 #endif
 
+#ifdef STACK_CHECK
+    cliPrintf("Stack used: %d, ", stackUsedSize());
+#endif
+    cliPrintf("Stack size: %d, Stack address: 0x%x\r\n", stackTotalSize(), stackHighMem());
+
     cliPrintf("Cycle Time: %d, I2C Errors: %d, config size: %d\r\n", cycleTime, i2cErrorCounter, sizeof(master_t));
 
 #ifdef USE_SDCARD

src/main/scheduler/scheduler.h

@@ -85,6 +85,9 @@ typedef enum {
 #ifdef TRANSPONDER
     TASK_TRANSPONDER,
 #endif
+#ifdef STACK_CHECK
+    TASK_STACK_CHECK,
+#endif
 #ifdef OSD
     TASK_OSD,
 #endif

src/main/startup/startup_stm32f40xx.s

@@ -71,6 +71,15 @@ defined in linker script */
   .weak  Reset_Handler
   .type  Reset_Handler, %function
 Reset_Handler: 
+  // Enable CCM
+  // RCC->AHB1ENR |= RCC_AHB1ENR_CCMDATARAMEN;
+  ldr     r0, =0x40023800       // RCC_BASE
+  ldr     r1, [r0, #0x30]       // AHB1ENR
+  orr     r1, r1, 0x00100000    // RCC_AHB1ENR_CCMDATARAMEN
+  str     r1, [r0, #0x30]
+  dsb
+
+  // Check for bootloader reboot
   ldr r0, =0x2001FFFC         // mj666
   ldr r1, =0xDEADBEEF         // mj666
   ldr r2, [r0, #0]            // mj666
@@ -106,6 +115,19 @@ LoopFillZerobss:
   cmp  r2, r3
   bcc  FillZerobss
 
+/* Mark the heap and stack */
+    ldr	r2, =_heap_stack_begin
+    b	LoopMarkHeapStack
+
+MarkHeapStack:
+	movs	r3, 0xa5a5a5a5
+	str	r3, [r2], #4
+
+LoopMarkHeapStack:
+	ldr	r3, = _heap_stack_end
+	cmp	r2, r3
+	bcc	MarkHeapStack
+
 /*FPU settings*/
  ldr     r0, =0xE000ED88           /* Enable CP10,CP11 */
  ldr     r1,[r0]

src/main/startup/startup_stm32f411xe.s

@@ -71,6 +71,15 @@ defined in linker script */
   .weak  Reset_Handler
   .type  Reset_Handler, %function
 Reset_Handler: 
+  // Enable CCM
+  // RCC->AHB1ENR |= RCC_AHB1ENR_CCMDATARAMEN;
+  ldr     r0, =0x40023800       // RCC_BASE
+  ldr     r1, [r0, #0x30]       // AHB1ENR
+  orr     r1, r1, 0x00100000    // RCC_AHB1ENR_CCMDATARAMEN
+  str     r1, [r0, #0x30]
+  dsb
+
+  // Check for bootloader reboot
   ldr r0, =0x2001FFFC         // mj666
   ldr r1, =0xDEADBEEF         // mj666
   ldr r2, [r0, #0]            // mj666
@@ -106,6 +115,19 @@ LoopFillZerobss:
   cmp  r2, r3
   bcc  FillZerobss
 
+/* Mark the heap and stack */
+    ldr	r2, =_heap_stack_begin
+    b	LoopMarkHeapStack
+
+MarkHeapStack:
+	movs	r3, 0xa5a5a5a5
+	str	r3, [r2], #4
+
+LoopMarkHeapStack:
+	ldr	r3, = _heap_stack_end
+	cmp	r2, r3
+	bcc	MarkHeapStack
+
 /*FPU settings*/
  ldr     r0, =0xE000ED88           /* Enable CP10,CP11 */
  ldr     r1,[r0]

src/main/target/link/stm32_flash.ld

@@ -12,11 +12,15 @@
 ENTRY(Reset_Handler)
 
 /* Highest address of the user mode stack */
-_estack = ORIGIN(RAM) + LENGTH(RAM);    /* end of RAM */
+_estack = ORIGIN(STACKRAM) + LENGTH(STACKRAM);    /* end of RAM */
+
+/* Base address where the config is stored. */
+__config_start = ORIGIN(FLASH_CONFIG);
+__config_end = ORIGIN(FLASH_CONFIG) + LENGTH(FLASH_CONFIG);
 
 /* Generate a link error if heap and stack don't fit into RAM */
 _Min_Heap_Size = 0;      /* required amount of heap  */
-_Min_Stack_Size = 0x400; /* required amount of stack */
+_Min_Stack_Size = 0x800; /* required amount of stack */
 
 /* Define output sections */
 SECTIONS
@@ -110,6 +114,9 @@ SECTIONS
   } >RAM
 
   /* User_heap_stack section, used to check that there is enough RAM left */
+  _heap_stack_end = ORIGIN(STACKRAM)+LENGTH(STACKRAM) - 8; /* 8 bytes to allow for alignment */
+  _heap_stack_begin = _heap_stack_end - _Min_Stack_Size  - _Min_Heap_Size;
+  . = _heap_stack_begin;
   ._user_heap_stack :
   {
     . = ALIGN(4);
@@ -118,7 +125,7 @@ SECTIONS
     . = . + _Min_Heap_Size;
     . = . + _Min_Stack_Size;
     . = ALIGN(4);
-  } >RAM
+  } >STACKRAM = 0xa5
 
   /* MEMORY_bank1 section, code must be located here explicitly            */
   /* Example: extern int foo(void) __attribute__ ((section (".mb1text"))); */