Enhanced startups for ARMCMx.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@7757 35acf78f-673a-0410-8e92-d51de3d6d3f4

4 files changed, 260 insertions, 441 deletions

diff --git a/os/common/ports/ARM/devices/LPC214x/armparams.h b/os/common/ports/ARM/devices/LPC214x/armparams.h
index 05ce875ec..9033e9e38 100644
--- a/os/common/ports/ARM/devices/LPC214x/armparams.h
+++ b/os/common/ports/ARM/devices/LPC214x/armparams.h
@@ -51,7 +51,7 @@
  */

 #define ARM_WFI_IMPL            (PCON = 1)

 

-#if !defined(__FROM_ASM__) || defined(__DOXYGEN__)

+#if !defined(_FROM_ASM_) || defined(__DOXYGEN__)

 /**

  * @brief   Address of the IRQ vector register in the interrupt controller.

  */

diff --git a/os/common/ports/ARMCMx/compilers/GCC/crt0.c b/os/common/ports/ARMCMx/compilers/GCC/crt0.c
index daa6a63aa..c3bb3fd79 100644
--- a/os/common/ports/ARMCMx/compilers/GCC/crt0.c
+++ b/os/common/ports/ARMCMx/compilers/GCC/crt0.c
@@ -18,205 +18,15 @@
 */

 

 /**

- * @file    ARMCMx/GCC/crt0.c

- * @brief   Generic GCC Cortex-Mx startup file.

+ * @file    ARMCMx/compilers/GCC/crt0.c

+ * @brief   Startup stub functions.

  *

  * @addtogroup ARMCMx_GCC_STARTUP

  * @{

  */

 

-#include <stdint.h>

 #include <stdbool.h>

 

-#if !defined(FALSE)

-#define FALSE       0

-#endif

-

-#if !defined(TRUE)

-#define TRUE        1

-#endif

-

-#define SCB_CPACR               *((uint32_t *)0xE000ED88U)

-#define SCB_FPCCR               *((uint32_t *)0xE000EF34U)

-#define SCB_FPDSCR              *((uint32_t *)0xE000EF3CU)

-#define FPCCR_ASPEN             (uint32_t)((uint32_t)0x1U << (uint32_t)31U)

-#define FPCCR_LSPEN             (uint32_t)((uint32_t)0x1U << (uint32_t)30U)

-

-typedef void (*funcp_t)(void);

-typedef funcp_t * funcpp_t;

-

-#define SYMVAL(sym) (uint32_t)&(sym)

-

-/*

- * Area fill code, it is a macro because here functions cannot be called

- * until stacks are initialized.

- */

-#define fill32(start, end, filler) do {                                     \

-  uint32_t *p1 = (start);                                                   \

-  uint32_t *p2 = (end);                                                     \

-  /*lint -save -e681 [2.1] Lint cannot see the scatter file symbols.*/      \

-  while (p1 < p2) {                                                         \

-  /*lint -restore*/                                                         \

-    *p1++ = (filler);                                                       \

-  }                                                                         \

-} while (false)

-

-/*===========================================================================*/

-/**

- * @name    Startup settings

- * @{

- */

-/*===========================================================================*/

-

-/**

- * @brief   Control special register initialization value.

- * @details The system is setup to run in privileged mode using the PSP

- *          stack (dual stack mode).

- */

-#if !defined(CRT0_CONTROL_INIT) || defined(__DOXYGEN__)

-#define CRT0_CONTROL_INIT           0x00000002

-#endif

-

-/**

- * @brief   Stack segments initialization switch.

- */

-#if !defined(CRT0_STACKS_FILL_PATTERN) || defined(__DOXYGEN__)

-#define CRT0_STACKS_FILL_PATTERN    0x55555555

-#endif

-

-/**

- * @brief   Stack segments initialization switch.

- */

-#if !defined(CRT0_INIT_STACKS) || defined(__DOXYGEN__)

-#define CRT0_INIT_STACKS            TRUE

-#endif

-

-/**

- * @brief   DATA segment initialization switch.

- */

-#if !defined(CRT0_INIT_DATA) || defined(__DOXYGEN__)

-#define CRT0_INIT_DATA              TRUE

-#endif

-

-/**

- * @brief   BSS segment initialization switch.

- */

-#if !defined(CRT0_INIT_BSS) || defined(__DOXYGEN__)

-#define CRT0_INIT_BSS               TRUE

-#endif

-

-/**

- * @brief   Constructors invocation switch.

- */

-#if !defined(CRT0_CALL_CONSTRUCTORS) || defined(__DOXYGEN__)

-#define CRT0_CALL_CONSTRUCTORS      TRUE

-#endif

-

-/**

- * @brief   Destructors invocation switch.

- */

-#if !defined(CRT0_CALL_DESTRUCTORS) || defined(__DOXYGEN__)

-#define CRT0_CALL_DESTRUCTORS       TRUE

-#endif

-

-/** @} */

-

-/*===========================================================================*/

-/**

- * @name    Symbols from the scatter file

- */

-/*===========================================================================*/

-

-/**

- * @brief   Main stack lower boundary.

- * @details This symbol must be exported by the linker script and represents

- *          the main stack lower boundary.

- */

-extern uint32_t __main_stack_base__;

-

-/**

- *

- * @brief   Main stack initial position.

- * @details This symbol must be exported by the linker script and represents

- *          the main stack initial position.

- */

-extern uint32_t __main_stack_end__;

-

-/**

- * @brief   Process stack lower boundary.

- * @details This symbol must be exported by the linker script and represents

- *          the process stack lower boundary.

- */

-extern uint32_t __process_stack_base__;

-

-/**

- * @brief   Process stack initial position.

- * @details This symbol must be exported by the linker script and represents

- *          the process stack initial position.

- */

-extern uint32_t __process_stack_end__;

-

-/**

- * @brief   ROM image of the data segment start.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern uint32_t _textdata;

-

-/**

- * @brief   Data segment start.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern uint32_t _data;

-

-/**

- * @brief   Data segment end.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern uint32_t _edata;

-

-/**

- * @brief   BSS segment start.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern uint32_t _bss_start;

-

-/**

- * @brief   BSS segment end.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern uint32_t _bss_end;

-

-/**

- * @brief   Constructors table start.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern funcp_t __init_array_start;

-

-/**

- * @brief   Constructors table end.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern funcp_t __init_array_end;

-

-/**

- * @brief   Destructors table start.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern funcp_t __fini_array_start;

-

-/**

- * @brief   Destructors table end.

- * @pre     The symbol must be aligned to a 32 bits boundary.

- */

-extern funcp_t __fini_array_end;

-

-/** @} */

-

-/**

- * @brief   Application @p main() function.

- */

-extern void main(void);

-

 /**

  * @brief   Early initialization.

  * @details This hook is invoked immediately after the stack initialization

@@ -255,119 +65,11 @@ void __late_init(void) {}
 __attribute__((noreturn, weak))

 #endif

 /*lint -save -e9075 [8.4] All symbols are invoked from asm context.*/

-void _default_exit(void) {

+void __default_exit(void) {

 /*lint -restore*/

 

   while (true) {

   }

 }

 

-/**

- * @brief   Reset vector.

- */

-#if !defined(__DOXYGEN__)

-__attribute__((naked))

-#endif

-/*lint -save -e9075 [8.4] All symbols are invoked from asm context.*/

-void Reset_Handler(void) {

-/*lint -restore*/

-  uint32_t psp, reg;

-

-  /* Process Stack initialization, it is allocated starting from the

-     symbol __process_stack_end__ and its lower limit is the symbol

-     __process_stack_base__.*/

-  __asm volatile ("cpsid   i");

-  psp = SYMVAL(__process_stack_end__);

-  __asm volatile ("msr     PSP, %0" : : "r" (psp));

-

-#if CORTEX_USE_FPU == TRUE

-  /* Initializing the FPU context save in lazy mode.*/

-  SCB_FPCCR = FPCCR_ASPEN | FPCCR_LSPEN;

-

-  /* CP10 and CP11 set to full access.*/

-  SCB_CPACR |= 0x00F00000U;

-

-  /* FPSCR and FPDSCR initially zero.*/

-  reg = 0;

-  __asm volatile ("vmsr    FPSCR, %0" : : "r" (reg) : "memory");

-  SCB_FPDSCR = reg;

-

-  /* CPU mode initialization, enforced FPCA bit.*/

-  reg = (uint32_t)CRT0_CONTROL_INIT | 4U;

-#else

-  /* CPU mode initialization.*/

-  reg = CRT0_CONTROL_INIT;

-#endif

-  __asm volatile ("msr     CONTROL, %0" : : "r" (reg));

-  __asm volatile ("isb");

-

-  /* Early initialization hook invocation.*/

-  __early_init();

-

-#if CRT0_INIT_STACKS == TRUE

-  /* Main and Process stacks initialization.*/

-  fill32(&__main_stack_base__,

-         &__main_stack_end__,

-         (uint32_t)CRT0_STACKS_FILL_PATTERN);

-  fill32(&__process_stack_base__,

-         &__process_stack_end__,

-         (uint32_t)CRT0_STACKS_FILL_PATTERN);

-#endif

-

-#if CRT0_INIT_DATA == TRUE

-  /* DATA segment initialization.*/

-  {

-    uint32_t *tp, *dp;

-

-    tp = &_textdata;

-    dp = &_data;

-    /*lint -save -e681 [2.1] Lint cannot see the scatter file symbols.*/

-    while (dp < &_edata) {

-    /*lint -restore*/

-      *dp++ = *tp++;

-    }

-  }

-#endif

-

-#if CRT0_INIT_BSS == TRUE

-  /* BSS segment initialization.*/

-  fill32(&_bss_start, &_bss_end, 0);

-#endif

-

-  /* Late initialization hook invocation.*/

-  __late_init();

-

-#if CRT0_CALL_CONSTRUCTORS

-  /* Constructors invocation.*/

-  {

-    funcpp_t fpp = &__init_array_start;

-    /*lint -save -e681 [2.1] Lint cannot see the scatter file symbols.*/

-    while (fpp < &__init_array_end) {

-    /*lint -restore*/

-      (*fpp)();

-      fpp++;

-    }

-  }

-#endif

-

-  /* Invoking application main() function.*/

-  main();

-

-#if CRT0_CALL_DESTRUCTORS == TRUE

-  /* Destructors invocation.*/

-  {

-    funcpp_t fpp = &__fini_array_start;

-    /*lint -save -e681 [2.1] Lint cannot see the scatter file symbols.*/

-    while (fpp < &__fini_array_end) {

-    /*lint -restore*/

-      (*fpp)();

-      fpp++;

-    }

-  }

-#endif

-

-  /* Invoking the exit handler.*/

-  _default_exit();

-}

-

 /** @} */

diff --git a/os/common/ports/ARMCMx/compilers/GCC/crt0_v6m.s b/os/common/ports/ARMCMx/compilers/GCC/crt0_v6m.s
index 962321cb2..38b4513b7 100644
--- a/os/common/ports/ARMCMx/compilers/GCC/crt0_v6m.s
+++ b/os/common/ports/ARMCMx/compilers/GCC/crt0_v6m.s
@@ -1,15 +1,14 @@
 /*

-    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,

-                 2011,2012 Giovanni Di Sirio.

+    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.

 

-    This file is part of ChibiOS/RT.

+    This file is part of ChibiOS.

 

-    ChibiOS/RT is free software; you can redistribute it and/or modify

+    ChibiOS 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.

 

-    ChibiOS/RT is distributed in the hope that it will be useful,

+    ChibiOS 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.

@@ -22,7 +21,7 @@
  * @file    crt0_v6m.s

  * @brief   Generic ARMv6-M (Cortex-M0/M1) startup file for ChibiOS.

  *

- * @addtogroup ARMCMx_GCC_STARTUP

+ * @addtogroup ARMCMx_GCC_STARTUP_V6M

  * @{

  */

 

@@ -114,9 +113,9 @@
 /*

  * Reset handler.

  */

+                .align  2

                 .thumb_func

                 .global Reset_Handler

-                .weak   Reset_Handler

 Reset_Handler:

                 /* Interrupts are globally masked initially.*/

                 cpsid   i

@@ -228,40 +227,8 @@ endfiniloop:
 #endif

 

                 /* Branching to the defined exit handler.*/

-                b       __default_exit

-

-/*--------------------------------------------------------------------------*

- * Default main exit code, the system is halted.

- * It is a weak symbol, the application code can redefine the behavior.

- * R0 contains the value returned by the main function.

- *--------------------------------------------------------------------------*/

-                .thumb_func

-                .weak   __default_exit

-__default_exit:

-                cpsid   i

-.loop:          b       .loop

-

-/*--------------------------------------------------------------------------*

- * Default early initialization code. It is declared weak in order to be

- * replaced by the real initialization code.

- * The early initialization is performed just after stacks setup RAM areas

- * initialization.

- *--------------------------------------------------------------------------*/

-                .thumb_func

-                .weak   __early_init

-__early_init:

-                bx      lr

-

-/*--------------------------------------------------------------------------*

- * Default late initialization code. It is declared weak in order to be

- * replaced by the real initialization code.

- * The late initialization is performed just after RAM areas initialization

- * and before invoking the static constructors.

- *--------------------------------------------------------------------------*/

-                .thumb_func

-                .weak   __late_init

-__late_init:

-                bx      lr

+                ldr     r1, =__default_exit

+                bx      r1

 

 #endif

 

diff --git a/os/common/ports/ARMCMx/compilers/GCC/crt0_v7m.s b/os/common/ports/ARMCMx/compilers/GCC/crt0_v7m.s
index 5aebe0e23..fcfa4decd 100644
--- a/os/common/ports/ARMCMx/compilers/GCC/crt0_v7m.s
+++ b/os/common/ports/ARMCMx/compilers/GCC/crt0_v7m.s
@@ -1,55 +1,151 @@
 /*

-    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,

-                 2011,2012 Giovanni Di Sirio.

+    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.

 

-    This file is part of ChibiOS/RT.

+    This file is part of ChibiOS.

 

-    ChibiOS/RT is free software; you can redistribute it and/or modify

+    ChibiOS 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.

 

-    ChibiOS/RT is distributed in the hope that it will be useful,

+    ChibiOS 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 this program.  If not, see <http://www.gnu.org/licenses/>.

-

-                                      ---

-

-    A special exception to the GPL can be applied should you wish to distribute

-    a combined work that includes ChibiOS/RT, without being obliged to provide

-    the source code for any proprietary components. See the file exception.txt

-    for full details of how and when the exception can be applied.

 */

 

 /**

  * @file    crt0_v7m.s

  * @brief   Generic ARMv7-M (Cortex-M3/M4/M7) startup file for ChibiOS.

  *

- * @addtogroup ARMCMx_GCC_STARTUP

+ * @addtogroup ARMCMx_GCC_STARTUP_V7M

  * @{

  */

 

+/*===========================================================================*/

+/* Module constants.                                                         */

+/*===========================================================================*/

+

 #if !defined(FALSE) || defined(__DOXYGEN__)

-#define FALSE   0

+#define FALSE                               0

 #endif

 

 #if !defined(TRUE) || defined(__DOXYGEN__)

-#define TRUE    1

+#define TRUE                                1

 #endif

 

-#if !defined(__DOXYGEN__)

+#define CONTROL_MODE_PRIVILEGED             0

+#define CONTROL_MODE_UNPRIVILEGED           1

+#define CONTROL_USE_MSP                     0

+#define CONTROL_USE_PSP                     2

+#define CONTROL_FPCA                        4

+

+#define FPCCR_ASPEN                         (1 << 31)

+#define FPCCR_LSPEN                         (1 << 30)

+

+#define SCB_CPACR                           0xE000ED88

+#define SCB_FPCCR                           0xE000EF34

+#define SCB_FPDSCR                          0xE000EF3C

+

+/*===========================================================================*/

+/* Module pre-compile time settings.                                         */

+/*===========================================================================*/

+

+/**

+ * @brief   Control special register initialization value.

+ * @details The system is setup to run in privileged mode using the PSP

+ *          stack (dual stack mode).

+ */

+#if !defined(CRT0_CONTROL_INIT) || defined(__DOXYGEN__)

+#define CRT0_CONTROL_INIT                   (CONTROL_USE_PSP |              \

+                                             CONTROL_MODE_PRIVILEGED)

+#endif

+

+/**

+ * @brief   Stack segments initialization switch.

+ */

+#if !defined(CRT0_STACKS_FILL_PATTERN) || defined(__DOXYGEN__)

+#define CRT0_STACKS_FILL_PATTERN            0x55555555

+#endif

+

+/**

+ * @brief   Stack segments initialization switch.

+ */

+#if !defined(CRT0_INIT_STACKS) || defined(__DOXYGEN__)

+#define CRT0_INIT_STACKS                    TRUE

+#endif

+

+/**

+ * @brief   DATA segment initialization switch.

+ */

+#if !defined(CRT0_INIT_DATA) || defined(__DOXYGEN__)

+#define CRT0_INIT_DATA                      TRUE

+#endif

+

+/**

+ * @brief   BSS segment initialization switch.

+ */

+#if !defined(CRT0_INIT_BSS) || defined(__DOXYGEN__)

+#define CRT0_INIT_BSS                       TRUE

+#endif

+

+/**

+ * @brief   Constructors invocation switch.

+ */

+#if !defined(CRT0_CALL_CONSTRUCTORS) || defined(__DOXYGEN__)

+#define CRT0_CALL_CONSTRUCTORS              TRUE

+#endif

+

+/**

+ * @brief   Destructors invocation switch.

+ */

+#if !defined(CRT0_CALL_DESTRUCTORS) || defined(__DOXYGEN__)

+#define CRT0_CALL_DESTRUCTORS               TRUE

+#endif

+

+/**

+ * @brief   FPU initialization switch.

+ */

+#if !defined(CRT0_INIT_FPU) || defined(__DOXYGEN__)

+#if defined(CORTEX_USE_FPU) || defined(__DOXYGEN__)

+#define CRT0_INIT_FPU                       CORTEX_USE_FPU

+#else

+#define CRT0_INIT_FPU                       FALSE

+#endif

+#endif

+

+/**

+ * @brief   FPU FPCCR register initialization value.

+ * @note    Only used if @p CRT0_INIT_FPU is equal to @p TRUE.

+ */

+#if !defined(CRT0_FPCCR_INIT) || defined(__DOXYGEN__)

+#define CRT0_FPCCR_INIT                     (FPCCR_ASPEN | FPCCR_LSPEN)

+#endif

+

+/**

+ * @brief   CPACR register initialization value.

+ * @note    Only used if @p CRT0_INIT_FPU is equal to @p TRUE.

+ */

+#if !defined(CRT0_CPACR_INIT) || defined(__DOXYGEN__)

+#define CRT0_CPACR_INIT                     0x00F00000

+#endif

 

-        .set    CONTROL_MODE_PRIVILEGED, 0

-        .set    CONTROL_MODE_UNPRIVILEGED, 1

-        .set    CONTROL_USE_MSP, 0

-        .set    CONTROL_USE_PSP, 2

+/*===========================================================================*/

+/* Code section.                                                             */

+/*===========================================================================*/

 

-                .cpu    cortex-m0

+#if !defined(__DOXYGEN__)

+

+                .syntax unified

+                .cpu    cortex-m3

+#if CRT0_INIT_FPU == TRUE

+                .fpu    fpv4-sp-d16

+#else

                 .fpu    softvfp

+#endif

 

                 .thumb

                 .text

@@ -57,88 +153,142 @@
 /*

  * Reset handler.

  */

-        .thumb_func

-        .global ResetHandler

-        .weak   ResetHandler

-ResetHandler:

-        /*

-         * Interrupts are globally masked initially.

-         */

-        cpsid   i

-        /*

-         * Stack pointers initialization.

-         */

-        ldr     r0, =__ram_end__

-        ldr     r1, =__main_stack_size__

-        subs    r0, r0, r1

-        /*

-         * Note that r0 is the main stack low boundary address and process

-         * stack initial top address.

-         */

-        msr     PSP, r0

-        /*

-         * Early initialization phase, it is empty by default.

-         */

-        bl      __early_init

-        /*

-         * Data initialization.

-         * NOTE: It assumes that the DATA size is a multiple of 4.

-         */

-        ldr     r1, =_textdata

-        ldr     r2, =_data

-        ldr     r3, =_edata

+                .align  2

+                .thumb_func

+                .global Reset_Handler

+Reset_Handler:

+                /* Interrupts are globally masked initially.*/

+                cpsid   i

+

+                /* PSP stack pointers initialization.*/

+                ldr     r0, =__process_stack_end__

+                msr     PSP, r0

+

+#if CRT0_INIT_FPU == TRUE

+                /* FPU FPCCR initialization.*/

+                movw    r0, #CRT0_FPCCR_INIT & 0xFFFF

+                movt    r0, #CRT0_FPCCR_INIT >> 16

+                movw    r1, #SCB_FPCCR & 0xFFFF

+                movt    r1, #SCB_FPCCR >> 16

+                str     r0, [r1]

+

+                /* CPACR initialization.*/

+                movw    r0, #CRT0_CPACR_INIT & 0xFFFF

+                movt    r0, #CRT0_CPACR_INIT >> 16

+                movw    r1, #SCB_CPACR & 0xFFFF

+                movt    r1, #SCB_CPACR >> 16

+                str     r0, [r1]

+

+                /* FPU FPSCR initially cleared.*/

+                mov     r0, #0

+                vmsr    FPSCR, r0

+

+                /* FPU FPDSCR initially cleared.*/

+                movw    r1, #SCB_FPDSCR & 0xFFFF

+                movt    r1, #SCB_FPDSCR >> 16

+                str     r0, [r1]

+

+                /* Enforcing FPCA bit in the CONTROL register.*/

+                movs    r0, #CRT0_CONTROL_INIT | CONTROL_FPCA

+

+#else

+                movs    r0, #CRT0_CONTROL_INIT

+#endif

+

+                /* CONTROL register initialization as configured.*/

+                msr     CONTROL, r0

+                isb

+

+                /* Early initialization..*/

+                bl      __early_init

+

+#if CRT0_INIT_STACKS == TRUE

+                ldr     r0, =CRT0_STACKS_FILL_PATTERN

+                /* Main Stack initialization. Note, it assumes that the

+                   stack size is a multiple of 4 so the linker file must

+                   ensure this.*/

+                ldr     r1, =__main_stack_base__

+                ldr     r2, =__main_stack_end__

+msloop:

+                cmp     r1, r2

+                itt     lo

+                strlo   r0, [r1], #4

+                blo     msloop

+

+                /* Process Stack initialization. Note, it assumes that the

+                   stack size is a multiple of 4 so the linker file must

+                   ensure this.*/

+                ldr     r1, =__process_stack_base__

+                ldr     r2, =__process_stack_end__

+psloop:

+                cmp     r1, r2

+                itt     lo

+                strlo   r0, [r1], #4

+                blo     psloop

+#endif

+

+#if CRT0_INIT_DATA == TRUE

+                /* Data initialization. Note, it assumes that the DATA size

+                  is a multiple of 4 so the linker file must ensure this.*/

+                ldr     r1, =_textdata

+                ldr     r2, =_data

+                ldr     r3, =_edata

 dloop:

-        cmp     r2, r3

-        ittt    lo

-        ldrlo   r0, [r1], #4

-        strlo   r0, [r2], #4

-        blo     dloop

-        /*

-         * BSS initialization.

-         * NOTE: It assumes that the BSS size is a multiple of 4.

-         */

-        movs    r0, #0

-        ldr     r1, =_bss_start

-        ldr     r2, =_bss_end

+                cmp     r2, r3

+                ittt    lo

+                ldrlo   r0, [r1], #4

+                strlo   r0, [r2], #4

+                blo     dloop

+#endif

+

+#if CRT0_INIT_BSS == TRUE

+                /* BSS initialization. Note, it assumes that the DATA size

+                  is a multiple of 4 so the linker file must ensure this.*/

+                movs    r0, #0

+                ldr     r1, =_bss_start

+                ldr     r2, =_bss_end

 bloop:

-        cmp     r1, r2

-        itt     lo

-        strlo   r0, [r1], #4

-        blo     bloop

-        /*

-         * Switches to the Process Stack and uses a barrier just to be safe.

-         */

-        movs    r0, #CONTROL_MODE_PRIVILEGED | CONTROL_USE_PSP

-        msr     CONTROL, r0

-        isb

-        /*

-         * Main program invocation.

-         */

-        bl      main

-        b       _main_exit_handler

+                cmp     r1, r2

+                itt     lo

+                strlo   r0, [r1], #4

+                blo     bloop

+#endif

 

-/*

- * Default main exit code, just a loop.

- * It is a weak symbol, the application code can redefine the behavior.

- */

-        .thumb_func

-        .global _main_exit_handler

-        .weak   _main_exit_handler

-_main_exit_handler:

-.loop:  b       .loop

+                /* Late initialization..*/

+                bl      __late_init

 

-/*

- * Default early initialization code. It is declared weak in order to be

- * replaced by the real initialization code.

- * The arly initialization is performed just after stacks setup and before BSS

- * and DATA segments initialization.

- */

-        .thumb_func

-        .global __early_init

-        .weak   __early_init

-__early_init:

-        bx      lr

+#if CRT0_CALL_CONSTRUCTORS == TRUE

+                /* Constructors invocation.*/

+                ldr     r4, =__init_array_start

+                ldr     r5, =__init_array_end

+initloop:

+                cmp     r4, r5

+                bge     endinitloop

+                ldr     r1, [r4], #4

+                blx     r1

+                b       initloop

+endinitloop:

+#endif

+

+                /* Main program invocation, r0 contains the returned value.*/

+                bl      main

 

+#if CRT0_CALL_CONSTRUCTORS == TRUE

+                /* Destructors invocation.*/

+                ldr     r4, =__fini_array_start

+                ldr     r5, =__fini_array_end

+finiloop:

+                cmp     r4, r5

+                bge     endfiniloop

+                ldr     r1, [r4], #4

+                blx     r1

+                b       finiloop

+endfiniloop:

 #endif

 

+                /* Branching to the defined exit handler.*/

+                b       __default_exit

+

+#endif /* !defined(__DOXYGEN__) */

+

 /** @} */