C++ and STM32

[mabl]

Hello together,

I tried using C++ with a basic Chibios project. I therefore renamed main.c to main.cpp and moved it to CPPSRC in the makefile. I thought that should work but i get a

Code: Select all

arm-none-eabi/bin/ld: error: no memory region specified for loadable section `.ARM.extab'

error. Even though the linker script seems to define the .ARM.extab section. I'm a dumb beginner on linker scripts. Does anybody have a tip for me?

[Giovanni]

Probably it is just the linker script that must be updated, it worked with older GCC versions.

I will include a C++ demo in next release, I promised that to Roberto too.

Giovanni

[Giovanni]

Hi,

I made some tests, that section is for exception handling, just add -fno-exceptions to the makefile:

USE_CPPOPT = -fno-rtti -fno-exceptions

Supporting exceptions would require more changes but I would not recommend exceptions in an embedded application anyway because the code size would explode.
If you want to support exceptions change the file ch.ld as follow:

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/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT 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,
    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/>.
*/

/*
 * ST32F103 memory setup.
 */
__main_stack_size__     = 0x0400;
__process_stack_size__  = 0x0400;
__stacks_total_size__   = __main_stack_size__ + __process_stack_size__;

MEMORY
{
    flash : org = 0x08000000, len = 128k
    ram : org = 0x20000000, len = 20k
}

__ram_start__           = ORIGIN(ram);
__ram_size__            = LENGTH(ram);
__ram_end__             = __ram_start__ + __ram_size__;

SECTIONS
{
    . = 0;

    .text : ALIGN(16) SUBALIGN(16)
    {
        _text = .;
        KEEP(*(vectors))
        *(.text)
        *(.text.*)
        *(.rodata)
        *(.rodata.*)
        *(.glue_7t)
        *(.glue_7)
        *(.gcc*)
        *(.ARM.extab)
        *(.ARM.extab.*)
    } > flash

    .ctors :
    {
        PROVIDE(_ctors_start_ = .);
        KEEP(*(SORT(.ctors.*)))
        KEEP(*(.ctors))
        PROVIDE(_ctors_end_ = .);
    } > flash

    .dtors :
    {
        PROVIDE(_dtors_start_ = .);
        KEEP(*(SORT(.dtors.*)))
        KEEP(*(.dtors))
        PROVIDE(_dtors_end_ = .);
    } > flash

    .ARM.extab : {*(.ARM.extab* .gnu.linkonce.armextab.*)}

    __exidx_start = .;
    .ARM.exidx : {*(.ARM.exidx* .gnu.linkonce.armexidx.*)} > flash
    __exidx_end = .;

    .eh_frame_hdr : {*(.eh_frame_hdr)}

    .eh_frame : ONLY_IF_RO {*(.eh_frame)}

    . = ALIGN(4);
    _etext = .;
    _textdata = _etext;

    .data :
    {
        _data = .;
        *(.data)
        . = ALIGN(4);
        *(.data.*)
        . = ALIGN(4);
        *(.ramtext)
        . = ALIGN(4);
        _edata = .;
    } > ram AT > flash

    .bss :
    {
        _bss_start = .;
        *(.bss)
        . = ALIGN(4);
        *(.bss.*)
        . = ALIGN(4);
        *(COMMON)
        . = ALIGN(4);
        _bss_end = .;
    } > ram    
}

PROVIDE(end = .);
_end            = .;

__heap_base__   = _end;
__heap_end__    = __ram_end__ - __stacks_total_size__;

You will get some undefined symbol errors from the linker, basically you have to provide those functions to newlib (just stub them to chHalt()).

Giovanni

[Giovanni]

BTW, I just added a C++ demo for the STM32 to the repository, it should work with little changes on any Cortex-Mx MCU.

Giovanni

[Dave_fr]

Hi,

I can't find any c++ demo in the repository ? Can you tell me what am I missing ?

BTW is there a "full" project example available somewhere ?

Dave

[Giovanni]

Hi Dave,

The demo is in the unstable version under ./demos/ARMCM3-STM32F103-G++, it is a full example and can be used as template for an application.

Giovanni

[Cyrille]

Hi,

I try to add a simple cpp file (Debug.cpp) in my STM32 project (composed by test.c file). I have the following error. The pb comes probably from the makeFile/compiler (see below). Does anyone have an idea ?

arm-none-eabi-gcc -c -mcpu=cortex-m3 -O2 -ggdb -fomit-frame-pointer -falign-functions=16 -ffunction-sections -fdata-sections -Wall -Wextra -Wstrict-prototypes -std=c99 -Wa,-alms=test.lst -DTHUMB_PRESENT -mno-thumb-interwork -DTHUMB_NO_INTERWORKING -MD -MP -MF .dep/test.o.d -mthumb -DTHUMB -I . -I../../os/ports/GCC/ARMCMx -I../../os/ports/GCC/ARMCMx/STM32 -I../../os/kernel/include -I../../os/hal/include -I../../os/hal/platforms/STM32 -I../../boards/MULTIPILOT32 -I../../os/various test.c -o test.o
In file included from test.c:5:0:
Debug.h:12:1: error: unknown type name 'class'
Debug.h:13:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
Debug.h:22:1: error: unknown type name 'Debug_Class'

Debug.cpp

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#ifndef DEBUG_H_
#define DEBUG_H_
#include <stdio.h>

class Debug_Class
{
public:
   Debug_Class();
   void putchar(uint8_t c);
   void putfloat(float x);
   void putlong(long x);
   void putint(int x);
};

extern Debug_Class Dbg;


#endif /* DEBUG_H_ */

MakeFile

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##############################################################################
# Build global options
# NOTE: Can be overridden externally.
#

# Compiler options here.
ifeq ($(USE_OPT),)
  USE_OPT = -O2 -ggdb -fomit-frame-pointer -falign-functions=16
endif

# C++ specific options here (added to USE_OPT).
ifeq ($(USE_CPPOPT),)
  USE_CPPOPT = -fno-rtti
endif

# Enable this if you want the linker to remove unused code and data
ifeq ($(USE_LINK_GC),)
  USE_LINK_GC = yes
endif

# If enabled, this option allows to compile the application in THUMB mode.
ifeq ($(USE_THUMB),)
  USE_THUMB = yes
endif

# Enable register caching optimization (read documentation).
ifeq ($(USE_CURRP_CACHING),)
  USE_CURRP_CACHING = no
endif

#
# Build global options
##############################################################################

##############################################################################
# Architecture or project specific options
#

# Enable this if you really want to use the STM FWLib.
ifeq ($(USE_FWLIB),)
  USE_FWLIB = no
endif

#
# Architecture or project specific options
##############################################################################

##############################################################################
# Project, sources and paths
#

# Define project name here
PROJECT = MP32TESTPROGRAM

# Define linker script file here
LDSCRIPT= ch.ld

# Imported source files
CHIBIOS = ../..
include $(CHIBIOS)/boards/MULTIPILOT32/board.mk
include $(CHIBIOS)/os/hal/platforms/STM32/platform.mk
include $(CHIBIOS)/os/hal/hal.mk
include $(CHIBIOS)/os/ports/GCC/ARMCMx/STM32/port.mk
include $(CHIBIOS)/os/kernel/kernel.mk
# include $(CHIBIOS)/test/test.mk

# C sources that can be compiled in ARM or THUMB mode depending on the global
# setting.
CSRC = $(PORTSRC) \
       $(KERNSRC) \
       $(TESTSRC) \
       $(HALSRC) \
       $(PLATFORMSRC) \
       $(BOARDSRC) \
       $(CHIBIOS)/os/various/evtimer.c \
       $(CHIBIOS)/os/various/syscalls.c \
       test.c


# C++ sources that can be compiled in ARM or THUMB mode depending on the global
# setting.
CPPSRC = 

# C sources to be compiled in ARM mode regardless of the global setting.
# NOTE: Mixing ARM and THUMB mode enables the -mthumb-interwork compiler
#       option that results in lower performance and larger code size.
ACSRC =

# C++ sources to be compiled in ARM mode regardless of the global setting.
# NOTE: Mixing ARM and THUMB mode enables the -mthumb-interwork compiler
#       option that results in lower performance and larger code size.
ACPPSRC =

# C sources to be compiled in THUMB mode regardless of the global setting.
# NOTE: Mixing ARM and THUMB mode enables the -mthumb-interwork compiler
#       option that results in lower performance and larger code size.
TCSRC =

# C sources to be compiled in THUMB mode regardless of the global setting.
# NOTE: Mixing ARM and THUMB mode enables the -mthumb-interwork compiler
#       option that results in lower performance and larger code size.
TCPPSRC =

# List ASM source files here
ASMSRC = $(PORTASM)

INCDIR = $(PORTINC) $(KERNINC) $(TESTINC) \
         $(HALINC) $(PLATFORMINC) $(BOARDINC) \
         $(CHIBIOS)/os/various

#
# Project, sources and paths
##############################################################################

##############################################################################
# Compiler settings
#

MCU  = cortex-m3

#TRGT = arm-elf-
TRGT = arm-none-eabi-
CC   = $(TRGT)gcc
CPPC = $(TRGT)g++
# Enable loading with g++ only if you need C++ runtime support.
# NOTE: You can use C++ even without C++ support if you are careful. C++
#       runtime support makes code size explode.
LD   = $(TRGT)gcc
LD   = $(TRGT)g++
CP   = $(TRGT)objcopy
AS   = $(TRGT)gcc -x assembler-with-cpp
OD   = $(TRGT)objdump
HEX  = $(CP) -O ihex
BIN  = $(CP) -O binary

# ARM-specific options here
AOPT =

# THUMB-specific options here
TOPT = -mthumb -DTHUMB

# Define C warning options here
CWARN = -Wall -Wextra -Wstrict-prototypes -std=c99 

# Define C++ warning options here
CPPWARN = -Wall -Wextra -std=c99 

#
# Compiler settings
##############################################################################

##############################################################################
# Start of default section
#

# List all default C defines here, like -D_DEBUG=1
DDEFS =

# List all default ASM defines here, like -D_DEBUG=1
DADEFS =

# List all default directories to look for include files here
DINCDIR =

# List the default directory to look for the libraries here
DLIBDIR =

# List all default libraries here
DLIBS =

#
# End of default section
##############################################################################

##############################################################################
# Start of user section
#

# List all user C define here, like -D_DEBUG=1
UDEFS =

# Define ASM defines here
UADEFS =

# List all user directories here
UINCDIR =

# List the user directory to look for the libraries here
ULIBDIR =

# List all user libraries here
ULIBS =

#
# End of user defines
##############################################################################

ifeq ($(USE_FWLIB),yes)
  include $(CHIBIOS)/ext/stm32lib/stm32lib.mk
  CSRC += $(STM32SRC)
  INCDIR += $(STM32INC)
  USE_OPT += -DUSE_STDPERIPH_DRIVER
endif

include $(CHIBIOS)/os/ports/GCC/ARMCMx/rules.mk
 

Thanks

[liamstask]

Hi Cyrille - looks like you are compiling that code as C, not C++. I would recommend putting that code into test.cpp instead of test.c and then, in the Makefile, adding it to the CPPSRC group instead of the CSRC group.

[Cyrille]

Hi Liamstak,

I have tested your recommendation and I have the following error :

c:/programmes/yagarto/bin/../lib/gcc/arm-none-eabi/4.6.0/../../../../arm-none-eabi/bin/ld.exe: error: no memory region specified for loadable section `.ARM.extab'
collect2: ld returned 1 exit status

[liamstask]

Hi Cyrille - the same error was reported above. Please take a look at the previous responses, and hopefully you should be able to resolve the issue.