arm-elf-gcc problem

Hi group,

I'm a newbie regarding the GNU ARM stuff. After many trials with intensive studying of the manuals for the gnu linker and assembler I have no more idea to solve the following problem:

I want to compile and link a very simple main.c with startup code and linker script (see below my sample files, its for ARM7TDMI). The linker, invoked by arm-elf-gcc, can't find the entry point symbol, which is referenced in my linker script and defined in the startup code as .global. The linker complains with:

arm-elf-gcc -nostartfiles -Wl,-Map=mapfile.map

-Wl,--script=my_linker_script -Wl,-cref cstartup.o main.o -o main.elf /gnuarm/bin/../lib/gcc-lib/arm-elf/3.3.3/../../../../arm-elf/bin/ld: warning: cannot find entry symbol __main; defaulting to 04000000

This is confusing because '__main' is defined as '.global' in the startup file. Did I miss something in the makefile? Hope anybody can give me hint.

Thanks in advance Steffen

The startup code fragment:

--------------------------

.include "../at91lib_gnu/periph/arm7tdmi/arm.inc" .include "phycore.inc" /****************************** code entry point

__main:

B InitReset /* reset */ undefvec: B undefvec /* Undefined Instruction */ swivec: B swivec /* Software Interrupt */ pabtvec: B pabtvec /* Prefetch Abort */ dabtvec: B dabtvec /* Data Abort */ rsvdvec: B rsvdvec /* reserved */ irqvec: B irqvec /* reserved */ fiqvec: B fiqvec /* reserved */

/* EBI Initialization Data */

InitTableEBI: .word EBI_CSR_0 .word EBI_CSR_1 .word EBI_CSR_2 .word EBI_CSR_3 .word EBI_CSR_4 .word EBI_CSR_5 .word EBI_CSR_6 .word EBI_CSR_7 .word 0x00000001 /* REMAP command */ .word 0x00000006 /* memory regions, standard read */

PtEBIBase: .word EBI_BASE /* EBI Base Address */

/* The reset handler before Remap From here, the code is executed from SRAM address Exporting labels used in other files

InitReset:

/* Load System EBI Base address and CSR0 Init Value

ldr r0, PtEBIBase ldr r1, InitTableEBI

/*- Speed up code execution by disabling wait state on Chip Select 0*/

str r1, [r0] bl __low_level_init

...and so on...

pretty simple main.c:

----------------------- int main(void) { int a,b; volatile int my_var;

a=10; b=20; my_var=a+b;

return 0; }

my linker script:

-----------------------

ENTRY(__main)

MEMORY { int_ram : org = 0x00000000, len = 8K /* internal RAM */ ram : org = 0x04000000, len = 1024K /* RAM at CS1 */ }

SECTIONS { .startup : { cstartup.o; *(.glue_7t); *(.glue_7); *(.rdata); *(.fini);

} > int_ram

.text : { main.o; *(.text); } > ram

.data : { *(.data); } > ram

.bss : { *(.bss) *(COMMON); } > ram }

my makefile:

---------------------------

CC = arm-elf-gcc AS = arm-elf-as

INC = INC += -I ../at91lib_gnu

ASM.FILES = ASM.FILES += cstartup.S

ASM.FLAGS += ASM.FLAGS += -mthumb-interwork ASM.FLAGS += -mcpu=arm7tdmi ASM.FLAGS += -gstabs

C.FILES = main.c

C.FLAGS += C.FLAGS += -c C.FLAGS += -g C.FLAGS += -mcpu=arm7tdmi C.FLAGS += -mthumb-interwork

L.FLAGS = L.FLAGS += -nostartfiles L.FLAGS += -Wl,-Map=mapfile.map L.FLAGS += -Wl,--script=my_linker_script L.FLAGS += -Wl,-cref

OBJ = OBJ += $(patsubst %.S,%.o,$(ASM.FILES)) OBJ += $(patsubst %.c,%.o,$(C.FILES))

%.o : %.S makefile $(AS) $(INC) $(ASM.FLAGS) $< -o $@

%.o : %.c makefile $(CC) $(INC) $(C.FLAGS) $< -o $@

all: $(OBJ)

exec: $(OBJ) $(CC) $(L.FLAGS) $(OBJ) -o main.elf

clean: rm *.o rm *.elf rm *.map