How to group objects from static library in a section?

[wyse03br@yahoo.com.br]

Hi all,

Using GNU linker ld, I'd like to create a section .rom_code
grouping
some routines and all its dependencies, including the implicit called
ones such as math routines provided by libm.a. Going down in more
details, my intention is creating a stand-alone ROM image containing
several utility routines (with all its dependencies) that will be used
by programs loaded in RAM.
The C code is something like:


% cat test.c <<HERE
#include <stdio.h>
#include <math.h>

void _start() { main(); }

extern int main();

volatile float a, b, c;
volatile float res;

__attribute__(( section(".rom_c ode"))) void rom_function();
void rom_function() {
c = a / b; // Use implicitely libm.a routine
res = sin(c); // Use explictly libm.a routine

}

int main() {
rom_function();
return 0;
}

HERE

% gcc -g test.c -lm -Wl,-T lib.lnk

Compiling and linking in the usual way, only the rom_function()
went to ROM, not its dependencies. These are the references
to .rom_code section, only the
rom_function() routine can be found there:

% objdump -x a.out | grep rom_code
7 .rom_code 00000070 00008000 00008000 00018000 2**2
00008000 l d .rom_code 00000000
00008000 g F .rom_code 00000070 rom_function

The sin() was placed in .text and not in .rom_code:

% objdump -x a.out | grep sin
00000000 l df *ABS* 00000000 s_sin.c
00000000 l df *ABS* 00000000 k_sin.c
00001438 g F .text 000000f8 __kernel_sin
00000514 g F .text 000000ec sin

The linker script used is:

MEMORY
{
RAM_CODE : o = 0x0000 , l = 0x8000
ROM_CODE : o = 0x8000 , l = 0x8000

}

SECTIONS
{
.bss : { *(.bss) } RAM_CODE
.sbss : { *(.sbss) } RAM_CODE
.rodata : { *(.rodata*) } RAM_CODE
.got2 : { *(.got*) } RAM_CODE
.data : { *(.data) } RAM_CODE
.sdata : { *(.sdata*) } RAM_CODE

.text : { *(.text .text.*) } RAM_CODE

.rom_code : { *(.rom_code) } ROM_CODE

}

Any ideas on how to put also the rom_function() dependencies into
ROM?

Tks

Walter

[Jack Klein]

Re: How to group objects from static library in a section?

On Thu, 27 Mar 2008 10:02:17 -0700 (PDT), wyse03br@yahoo. com.br wrote
in comp.lang.c:

Hi all,
>
Using GNU linker ld, I'd like to create a section .rom_code
grouping
some routines and all its dependencies, including the implicit called
ones such as math routines provided by libm.a. Going down in more
details, my intention is creating a stand-alone ROM image containing
several utility routines (with all its dependencies) that will be used
by programs loaded in RAM.
The C code is something like:

[snip]

Your question has nothing at all to do with the C language, and
everything to do with your particular tool set and target. C does not
have ROM images or sections.

You need to ask this question in a GNU support group, or, since you
mention ROM, perhaps in news:comp.arch. embedded where such questions
for embedded system development are topical. But if you ask there,
you had better provide more information, such as the target and
version of the tools.

--
Jack Klein
Home: http://JK-Technology.Com
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