String manipulation problems

[LordMark]

Hi everyone. I'm working on M52259demokit, CW 7.2.1 and MQX 3.6.1.

I have to manipulate some strings: I have a main string, called "buffer", which contains several numbers (double and integers) separated by "S". I need to split the above string into these numbers and save them to variables.

First trial was:

result = sscanf (buffer, "%fS%fS%fS%fS%dS%dS%dS%dS%dS%dS%dSC%d", &LONG, &LAT, &AZ_b, &H_b, &dd, &mm, &yy, &hr, &min, &sec, &TZ, &chksum);

where I tried all the format for double, %.10f, %lf etc.. this sscanf returns always 0. I'm also using the directive

#define MQX_INCLUDE_FLOATING_POINT_IO  1

 in user_config.h. Are there any limitation in sscanf? Maybe too many arguments?

The second trial was:

strcpy (LONG_string, strtok (buffer, "SC"));

that should be repeated for every substring I want to save. But I get the following link errors:

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_n'            
from address 0x00036B40 in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_n'            
from address 0x00036B2E in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_s@0'            
from address 0x00036B42 in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_s@0'            
from address 0x00036B36 in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_s@0'            
from address 0x00036B30 in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_s@0'            
from address 0x00036AC8 in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link Error   : Illegal 16-bit small data area relative reference to symbol '_@LOCAL@strtok__FPcPCc@strtok_s@0'            
from address 0x00036A9E in section '.text' of file 'libc.a string.o       '.         
This type of reference has a range from 4294934528 to 32767 bytes.
Project: MQX_ARCH.mcp, Target: Int Flash Debug

Link failed.

Any suggestions?

Thank you,
Marco

[LordMark]

Well, I found out that the problem is in the float/double formatter in sscanf. If I decide to scan a string with only integer formatter I get the right result. So, which is the right formatter save double precision variables from a string?

Regards,

Marco

[LordMark]

Finally I found the real cause of all those problems. It is the linker file that I modified to have my non volatile section of ram (nvram). You can see it in the code below. If I restore the original linker file those string function work fine.

MEMORY{## intflash    (RX): ORIGIN = 0x00000000, LENGTH = 0x00080000## sram        (RW): ORIGIN = 0x20000000, LENGTH = 0x00010000   vectorrom   (RX): ORIGIN = 0x00000000, LENGTH = 0x00000400   cfmprotrom  (RX): ORIGIN = 0x00000400, LENGTH = 0x00000020   rom         (RX): ORIGIN = 0x00000420, LENGTH = 0x0007FBE0  # Code + Const data    ram         (RW): ORIGIN = 0x20000000, LENGTH = 0x00010000  # SRAM - RW data#   relocate    (RWX): ORIGIN = 0x20003F00, LENGTH = 0x0000C100      # kernel space starts after RAM variables (Location of MQX Kernel data + MQX heap)   end_of_kd   (RW): ORIGIN = 0x2000FFF0, LENGTH = 0x00000000      # Boot stack reused by MQX Kernel data   bstack      (RW): ORIGIN = 0x2000FA00, LENGTH = 0x00000200  # Boot stack   end_bstack  (RW): ORIGIN = 0x2000FBFF, LENGTH = 0x00000000}KEEP_SECTION { .vectors_rom, .vectors_ram, .cfmconfig }SECTIONS{   ___INTERNAL_SRAM_BASE  = 0x20000000;   ___INTERNAL_SRAM_SIZE  = 0x00010000;   ___INTERNAL_FLASH_BASE = 0x00000000;   ___INTERNAL_FLASH_SIZE = 0x00080000;    ___IPSBAR              = 0x40000000; # Peripherals/FlexCAN    ___VECTOR_TABLE_START  = 0x20000000; # Runtime vector table in sram   # MQX link time configurations   ___DEFAULT_PROCESSOR_NUMBER = 1;   ___DEFAULT_INTERRUPT_STACK_SIZE = 1024;   ___KERNEL_DATA_VERIFY_ENABLE = 0;    # Test SDRAM read/write   # Flashx configurations   ___FLASHX_SECT_SIZE = 0x1000; .vectors : {        ___VECTOR_TABLE_ROM_START = .;  # Runtime vector table in sram  *(.vectors_rom)  . = ALIGN (0x4);  } > vectorrom .cfmprotect : {  *(.cfmconfig)  . = ALIGN (0x4); } > cfmprotrom    .main_application :   {      *(KERNEL)      *(S_BOOT)      *(IPSUM)      *(.text)      *(.init)      *(.fini)      *(.eini)      *(.ctors)      *(.dtors)      .= ALIGN(0x4);      *(.rodata)      .= ALIGN(0x4);      *(.rdata)      . = ALIGN(0x4);      *(.exception)      . = ALIGN(0x4);      __exception_table_start__ = .;      EXCEPTION      __exception_table_end__ = .;      ___sinit__ = .;      STATICINIT      .= ALIGN(0x4);      __COPY_OF_DATA = .;   } > rom      .main_application_data : AT(__COPY_OF_DATA)   {        . = ALIGN(0x10000);        ___VECTOR_TABLE_RAM_START = .;  # Runtime vector table in sram  *(.vectors_ram)        . = ALIGN(512);        __BDT_BASE = .;        *(.usb_bdt)        __BDT_END = .;      __START_DATA = .;      *(.data)      __END_DATA = .;      __START_DATA = .;      *(.my_zone)      __END_DATA = .;      . = ALIGN(0x4);      __SDA_BASE  = .;      __SDA_BASE_ = __SDA_BASE;   } > ram   .main_application_bss :   {      __START_SBSS = .;      *(.sbss)      *(SCOMMON)      __END_SBSS = .;      __START_BSS = .;      *(.bss)      *(COMMON)      __END_BSS = .;   } >> ram      .nvram :   {      __START_MYRAM = .;      *(.nvram)      __END_MYRAM = .;   } >> ram    .kernel_data : #AT(ADDR(.main_application_bss) + SIZEOF(.main_application_bss))   {      ___KERNEL_DATA_START = ALIGN(0x10);   }   .end_of_kernel_data :   {      ___KERNEL_DATA_END = .;   } > end_of_kd   .boot_stack :   {      _stack_end = .;   } > bstack   .end_of_boot_stack :   {      _stack_addr  = .;      __SP_INIT    = .;      ___BOOT_STACK_ADDRESS = .;   } > end_bstack   # Locate the ROM copy table into ROM after the initialized data   _romp_at = __COPY_OF_DATA + SIZEOF(.main_application_data);   .romp : AT (_romp_at)   {      __S_romp = _romp_at;      WRITEW(__COPY_OF_DATA);   #ROM start address      WRITEW(ADDR(.main_application_data));      #RAM start address      WRITEW(SIZEOF(.main_application_data));    #size      WRITEW(0);      WRITEW(0);      WRITEW(0);   }    _flashx_start = __COPY_OF_DATA + SIZEOF(.main_application_data) +     SIZEOF(.romp); # flashx working area spans across the whole rest of Flash memory    ___FLASHX_START_ADDR = (_flashx_start + 0xfff) / 0x1000 * 0x1000;    ___FLASHX_END_ADDR = ___INTERNAL_FLASH_BASE + ___INTERNAL_FLASH_SIZE;}/* EOF */

Any suggestion on how to solve the problems?

Regards,

Marco

[DavidS · Accepted solution]

Hi Marco,

I played around with your issue and now can read in your string, parse it, and get the variables into the right locations.

What I discovered is the sscanf() with the #define MQX_INCLUDE_FLOATING_POINT_IO 1 in the user_config.h, uses double for the string conversion.  So when I originally created a buffer using a float then passed the buffer to sscanf it returned wrong conversion.  But when I used double for the formatting of the buffer it works.

I started with the simple hello project in mqx/examples and have included the source file for your reference.

Hopefully this helps.

Regards,

David

[LordMark]

Hi Davids, the problem was already solved. There were bad lines in my linker file.

Anyway I may be reading a useful information in your post. You're saying that if MQX_INCLUDE_FLOATING_POINT_IO is defined as 0, sscanf accepts only float variables as arguments, wasting obviously much less memory than the case in which double precision is used. Have I understood right?

[DavidS]

Hi Marco,

What I've seen on the code base is that if you want to use floating point format the code #define MQX_INCLUDE_FLOATING_POINT_IO 1 must be in the user_config.h.

If the #define is 0 or not included, then the code base doesn't support the floating point (more correctly the double format).

So it is a binary decision....if wanting floating point formating you must define your variable as "double".  The code base just does not support the "float" option.

You can review the code in mqx/source/fio/io_scanl.c source file.

Regards,

David

[LordMark]

Ok, the problem was this subsection

__START_DATA = .;
      *(.my_zone)
      __END_DATA = .;

in section .main_application_data.