Reposition heap at the end of RAM to be 4K aligned

Deepika · deepikabhavnani · commit 37bfc9e5e391 · 2018-10-10T10:10:43.000-05:00
HEAP memory should be 4K aligned for GCC newlib, with ISR stack at the end of
RAM memory we loose 3K of RAM memory. This fix is for device with &lt;16K RAM to
use RAM entirely.
diff --git a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_GCC_ARM/STM32F070XB.ld b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_GCC_ARM/STM32F070XB.ld
@@ -1,4 +1,5 @@
 /* Linker script to configure memory regions. */
+StackSize = 0x400;
 MEMORY
 { 
   FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 128k
@@ -113,6 +114,20 @@ SECTIONS
 
     } > RAM
 
+    /* .stack section doesn't contains any symbols. It is only
+     * used for linker to reserve space for the main stack section
+     */
+    .stack (NOLOAD):
+    {
+        __StackLimit = .;
+        *(.stack*);
+        . += StackSize - (. - __StackLimit);
+    } > RAM
+    __StackTop = ADDR(.stack) + SIZEOF(.stack);
+    _estack = __StackTop;
+    __StackLimit = ADDR(.stack);
+    PROVIDE(__stack = __StackTop);
+
     .bss :
     {
         . = ALIGN(4);
@@ -129,25 +144,13 @@ SECTIONS
     {
         __end__ = .;
         end = __end__;
-        *(.heap*)
+        *(.heap*);
+        . += (ORIGIN(RAM) + LENGTH(RAM) - .);
         __HeapLimit = .;
     } > RAM
 
-    /* .stack_dummy section doesn't contains any symbols. It is only
-     * used for linker to calculate size of stack sections, and assign
-     * values to stack symbols later */
-    .stack_dummy (COPY):
-    {
-        *(.stack*)
-    } > RAM
-
-    /* Set stack top to end of RAM, and stack limit move down by
-     * size of stack_dummy section */
-    __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-    _estack = __StackTop;
-    __StackLimit = __StackTop - SIZEOF(.stack_dummy);
-    PROVIDE(__stack = __StackTop);
+    PROVIDE(__heap_size = SIZEOF(.heap));
+    PROVIDE(__mbed_sbrk_start = ADDR(.heap));
+    PROVIDE(__mbed_krbs_start = ADDR(.heap) + SIZEOF(.heap));
 
-    /* Check if data + heap + stack exceeds RAM limit */
-    ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
 }
diff --git a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_GCC_ARM/STM32F0xxx_retarget.c b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_GCC_ARM/STM32F0xxx_retarget.c
@@ -0,0 +1,54 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <errno.h>
+#include "stm32f0xx.h"
+extern uint32_t __mbed_sbrk_start;
+extern uint32_t __mbed_krbs_start;
+
+/* Support heap with two-region model
+ *
+ * The default implementation of _sbrk() (in mbed_retarget.cpp) for GCC_ARM requires one-region
+ * model (heap and stack share one region), which doesn't fit two-region model (heap and stack
+ * are two distinct regions)
+ * Hence, override _sbrk() here to support heap with two-region model.
+ */
+void *_sbrk(int incr)
+{
+    static uint32_t heap_ind = (uint32_t) &__mbed_sbrk_start;
+    uint32_t heap_ind_old = heap_ind;
+    uint32_t heap_ind_new = heap_ind_old + incr;
+
+    if (heap_ind_new > (uint32_t) &__mbed_krbs_start) {
+        errno = ENOMEM;
+        return (void *) -1;
+    }
+
+    heap_ind = heap_ind_new;
+
+    return (void *) heap_ind_old;
+}
diff --git a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_GCC_ARM/STM32F072XB.ld b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_GCC_ARM/STM32F072XB.ld
@@ -1,4 +1,5 @@
 /* Linker script to configure memory regions. */
+StackSize = 0x400;
 MEMORY
 { 
   FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 128k
@@ -113,6 +114,20 @@ SECTIONS
 
     } > RAM
 
+    /* .stack section doesn't contains any symbols. It is only
+     * used for linker to reserve space for the main stack section
+     */
+    .stack (NOLOAD):
+    {
+        __StackLimit = .;
+        *(.stack*);
+        . += StackSize - (. - __StackLimit);
+    } > RAM
+    __StackTop = ADDR(.stack) + SIZEOF(.stack);
+    _estack = __StackTop;
+    __StackLimit = ADDR(.stack);
+    PROVIDE(__stack = __StackTop);
+
     .bss :
     {
         . = ALIGN(4);
@@ -129,25 +144,13 @@ SECTIONS
     {
         __end__ = .;
         end = __end__;
-        *(.heap*)
+        *(.heap*);
+        . += (ORIGIN(RAM) + LENGTH(RAM) - .);
         __HeapLimit = .;
     } > RAM
 
-    /* .stack_dummy section doesn't contains any symbols. It is only
-     * used for linker to calculate size of stack sections, and assign
-     * values to stack symbols later */
-    .stack_dummy (COPY):
-    {
-        *(.stack*)
-    } > RAM
-
-    /* Set stack top to end of RAM, and stack limit move down by
-     * size of stack_dummy section */
-    __StackTop = ORIGIN(RAM) + LENGTH(RAM);
-    _estack = __StackTop;
-    __StackLimit = __StackTop - SIZEOF(.stack_dummy);
-    PROVIDE(__stack = __StackTop);
+    PROVIDE(__heap_size = SIZEOF(.heap));
+    PROVIDE(__mbed_sbrk_start = ADDR(.heap));
+    PROVIDE(__mbed_krbs_start = ADDR(.heap) + SIZEOF(.heap));
 
-    /* Check if data + heap + stack exceeds RAM limit */
-    ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
 }
diff --git a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_GCC_ARM/STM32F0xxx_retarget.c b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_GCC_ARM/STM32F0xxx_retarget.c
@@ -0,0 +1,54 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <errno.h>
+#include "stm32f0xx.h"
+extern uint32_t __mbed_sbrk_start;
+extern uint32_t __mbed_krbs_start;
+
+/* Support heap with two-region model
+ *
+ * The default implementation of _sbrk() (in mbed_retarget.cpp) for GCC_ARM requires one-region
+ * model (heap and stack share one region), which doesn't fit two-region model (heap and stack
+ * are two distinct regions)
+ * Hence, override _sbrk() here to support heap with two-region model.
+ */
+void *_sbrk(int incr)
+{
+    static uint32_t heap_ind = (uint32_t) &__mbed_sbrk_start;
+    uint32_t heap_ind_old = heap_ind;
+    uint32_t heap_ind_new = heap_ind_old + incr;
+
+    if (heap_ind_new > (uint32_t) &__mbed_krbs_start) {
+        errno = ENOMEM;
+        return (void *) -1;
+    }
+
+    heap_ind = heap_ind_new;
+
+    return (void *) heap_ind_old;
+}
diff --git a/targets/TARGET_STM/mbed_rtx.h b/targets/TARGET_STM/mbed_rtx.h
@@ -137,10 +137,22 @@ extern uint32_t               __HeapLimit[];
 #endif
 
 #if (defined(TARGET_STM32F070RB) || defined(TARGET_STM32F072RB))
+#if (defined(__GNUC__) && !defined(__CC_ARM) && !defined(__ARMCC_VERSION))
+extern uint32_t               __StackLimit;
+extern uint32_t               __StackTop;
+extern uint32_t               __end__;
+extern uint32_t               __HeapLimit;
+#define HEAP_START            ((unsigned char*) &__end__)
+#define HEAP_SIZE             ((uint32_t)((uint32_t) &__HeapLimit - (uint32_t) HEAP_START))
+#define ISR_STACK_START       ((unsigned char*) &__StackLimit)
+#define ISR_STACK_SIZE        ((uint32_t)((uint32_t) &__StackTop - (uint32_t) &__StackLimit))
+#endif
+
 #ifdef MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE
 #undef MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE
 #endif
 #define MBED_CONF_RTOS_MAIN_THREAD_STACK_SIZE 3072
+
 #endif
 
 #endif  // MBED_MBED_RTX_H
