[avr-gcc-list] Re:Strings in ROM

[Robert von Knobloch]

From: Eric Weddington:

This sounds like a linker error. It would help if you could post the actual 
output from the toolchain.

OK Eric, here goes. I have shortened everything to make it more readable (and 
less boring).
There are 10 sections of each type in fact.

The result of 'Make' is:


address@hidden:~/Version 0.8> make
avr-gcc -g -Wall -Os -mmcu=atmega644 -DF_CPU=20000000      -c -o main.o
main.c
tests.c:227: error: press_button causes a section type conflict
make: *** [main.o] Error 1
address@hidden:~/Version 0.8>

Where the makefile contains:

PRG            = main
OBJ            = $(PRG).o
MCU_TARGET     = atmega644
OPTIMIZE       = -Os

F_CPU        = 20000000   

DEFS           = -DF_CPU=$(F_CPU)
LIBS           =

CC             = avr-gcc

CFLAGS        = -g -Wall $(OPTIMIZE) -mmcu=$(MCU_TARGET) $(DEFS)
LDFLAGS       = -Wl,-Map,$(PRG).map \
        -Wl,--section-start=.test0=0x2600 \
        -Wl,--section-start=.testparms0=0x2e80 \
        -Wl,--section-start=.test1=0x2f00 \
        -Wl,--section-start=.testparms1=0x3780 \
        -Wl,--section-start=.flashimage=0x8000 \
        -Wl,--section-start=.bootloader=0xe000 \
        -Wl,--section-start=.functions=0xff00

In "hardware.h" (included in main) the mapping of the sections:

#define TESTIMAGE 0x2600            // Base address of test images

#define TEST0_SECTION __attribute__((section (".test0")))
#define TEST1_SECTION __attribute__((section (".test1")))

#define TESTPARMS0_SECTION __attribute__((section (".testparms0")))
#define TESTPARMS1_SECTION __attribute__((section (".testparms1")))

#define FUNCTION_SECTION   __attribute__((section (".functions")))

And in "tests.c" (inluded in main):

/*
 ******************************************************************************
 *   Tester routine 1
 ******************************************************************************
 */

#undef CODESECTION
#define CODESECTION TEST1_SECTION
extern char press_button[];
extern char button_timeout[];

CODESECTION uint16_t test1(void)
{
    ... test programme
}

CODESECTION char press_button[]        = ">>  Press UUT button  <<";  
//***** This one produces the error.
// If the preceding function test1() is removed (only other object in
this section), the error goes away.

#undef PARMSECTION
#define PARMSECTION TESTPARMS1_SECTION
PARMSECTION uint16_t flash1 = 1024;                // Bytes
PARMSECTION uint16_t eep1   = 64;                // Bytes
PARMSECTION uint8_t sig1[]  = {0x00, 0x00, 0x00};        // Test file
PARMSECTION uint8_t fuse1[] = {0xfb, 0x13};            // Big-Endian
PARMSECTION uint8_t np1        = 32;                // Flash
PARMSECTION uint8_t ps1        = 16;                // In 16-bit words
PARMSECTION uint8_t ts1        = 1;                // Slot in NKP
tester[0-9]
PARMSECTION uint8_t tr1        = 1;                // Routine in tester[0-9]
PARMSECTION char pn1[]        = "RKB Test V0.01          ";   // Pad to
exactly 24 chars

//Local constants
PARMSECTION char button_timeout[]   = "******* Timeout ******* ";  
//***** This one works OK, but I have insufficient space here.

So my conlusion is that the toolchain is treating a section containing a
function as .text and refusing to place the string in it.
When the section contains no function, then it is accepted.

Hope this makes sense.

Regards,

Robert