Move specific function to ITCM ram from library

[SeyyedMohammad]

I want to move some function from library (DSP cmsis) to ITCM of MCU. I can't move it's myLib.o completely since it's big. I mean *myLib.a:*(.text .text*) (copied from AN4296). what is the right output-section-command to do my job?

Assume I want to move `void arm_lms_f32(.....)` and the objdump -t output of library file is:

arm_lms_norm_f32.o:   file format elf32-little
 
SYMBOL TABLE:
00000000 l  df *ABS* 00000000 arm_lms_norm_f32.c
00000000 l  d .text 00000000 .text
00000000 l  d .data 00000000 .data
00000000 l  d .bss  00000000 .bss
00000000 l  d .text.arm_lms_norm_f32 00000000 .text.arm_lms_norm_f32
00000000 l    .text.arm_lms_norm_f32 00000000 $t
00000000 l  d .debug_info  00000000 .debug_info
00000000 l  d .debug_abbrev 00000000 .debug_abbrev
00000000 l  d .debug_loc   00000000 .debug_loc
00000000 l  d .debug_aranges 00000000 .debug_aranges
00000000 l  d .debug_ranges 00000000 .debug_ranges
00000000 l  d .debug_line  00000000 .debug_line
00000000 l  d .debug_str   00000000 .debug_str
00000000 l  d .debug_frame  00000000 .debug_frame
00000000 l  d .comment    00000000 .comment
00000000 l  d .ARM.attributes    00000000 .ARM.attributes
00000000     *UND* 00000000 __aeabi_fmul
00000000     *UND* 00000000 __aeabi_fsub
00000000     *UND* 00000000 __aeabi_fadd
00000000     *UND* 00000000 __aeabi_fdiv
00000001 g   F .text.arm_lms_norm_f32 000002b2 arm_lms_norm_f32
 
 
arm_lms_init_q31.o:   file format elf32-little
 
SYMBOL TABLE:
00000000 l  df *ABS* 00000000 arm_lms_init_q31.c
00000000 l  d .text 00000000 .text
.
.
.

I have write the linker script for general movement of newly defined functions in .c file and required startup modification:

_sifastcode = LOADADDR(.fastcode);
  .fastcode :
  {
	  . = ALIGN(4);
	  _sfastcode = .;
	  *(.fastcode)
	  *(.fastcode*)
      /*IN BETWEEN*/
	  . = ALIGN(4);
	  _efastcode = .;
  } >ITCMRAM AT> FLASH

I just need the required command to place in between.

There is a code copied from CCM RAM application not:

*myLib.a:*(.text .text.arm_lms_norm_f32)

I've found a way to do this by:

libarm_cortexM7lfdp_math.a:arm_fir_f32.o(.txt .txt*)

But whats wrong? Since I think this doesn't work.

[MM..1 · Accepted solution]

     /* Exclude file(s) from NewLib libc.a from .text.* section  */     
     *(EXCLUDE_FILE (*libc.a:lib_a-memcpy-stub.o) .text*)   

all info HOWTO: Execute a library function from RAM memory ... - NXP Community

[SeyyedMohammad]

Hi @MM..1​ 

But I think I don't need to exclude. I can include what I want in this manner, Am I right?

libarm_cortexM7lfdp_math.a:arm_fir_f32.o(.txt .txt*)

[MM..1]

you need exclude from text section and include into ram section as describ ein NXP.

section is .text and

Note

If you are placing a function into RAM always consider to add sub-functions called by that function (typically located in a different object file).

[SeyyedMohammad]

Hi @MM..1​ 

I've replaced:

.text :
{
.=ALIGN(4);
*(.text*) ->
*(EXCLUDE_FILE (*arm_cortexM7lfdp_math.a:arm_*.o) .text*)
 
/*IN BETWEEN*/ ->
*arm_cortexM7lfdp_math.a:arm_*.o(.text*)

these to move all cmsis dsp code to ITCMRAM and worked just fine, thank you kindely.

[SeyyedMohammad]

Hi again @MM..1​ 

What will happen if not placing some subfunctions? I've seen some wired symbols apperas with postfix _veneer for those not moved functions!

[SeyyedMohammad]

Hi @MM..1​ 

It worked but I wonder why AN4296 about CCM RAM doesn't mentioned anything about excluding the including ones?

[MM..1]

If you use  __attribute__((section or full lib exclude isnt required.

But normal default place for ... is flash , then one function need excl.

[SeyyedMohammad]

Hi @MM..1​ 

That doc introduced to add library to project. Not only using __attribute__ !!

[MM..1]

What isnt clean? Libs cant be defined with attribute then require include exclude in linker.

Exclude only if part of lib is in flash and other parts in other place.