Re: V850, linker script problem

[Torsten Mohr <tmohr at s dot netic dot de>]

Hi,

i'm sorry to bother you with this one again, but i'm not sure if
the behaviour below is a bug or if i do something wrong.  As
i haven't received any answers i think that nobody can easily
say where i did something wrong.  But i'm not sure about that.

It would be great if anybody could give me a comment if the
behaviour below looks like i did something wrong or if it
basically should work.

At the moment i have no clue on how to continue.  One more thing,
the toolchain is set up on MSYS/MinGW and i manually changed two
thing:
1. changed gcc/Makefile to NOT use/build collect2.exe
2. gcc/config/v850/lib1funcs.asm, line 1459 i commented out
   the change of the section


Thanks for any hints,
Torsten.


> Hi,
>
> thank you all for the hints so far, but until now i still
> have the problem with the linker script.
>
> I tried to cut down the project as much as possible to only
> reflect the strange behaviour and not much more.
>
> In the linker script v850.x i put .data to ROM to copy it into
> RAM at startup.  This results in the mapfile:
>
> From linker Script:
>   .data :
>   {
>     *(.data)
>     *(.data.*)
>     *(.gnu.linkonce.d*)
>     CONSTRUCTORS
>   } > ram AT > rom
>
>
> From map file:
>
> .data           0x03ffe000        0x0 load address 0x00000678
>  *(.data)
>  *(.data.*)
>  *(.gnu.linkonce.d*)
>
> I expected the same for .tdata and even more for .sdata as this
> one has only one entry, but i get:
>
>
> From linker script:
>   .tdata ALIGN(4) :
>   {
> 	*(.tbyte)
> 	*(.tcommon_byte)
> 	*(.tdata)
> 	*(.tbss)
> 	*(.tcommon)
>   } >ram AT>rom
>
>   __ep = ADDR(.tdata);
>
>
>   .sdata ALIGN (4) :
>   {
> 	*(.sdata)
>   } >ram AT > rom
>   __gp = ADDR(.sdata) + 0x8000;
>
>
> From map file:
>
> .tdata          0x00000678        0x0 load address 0x00000678
>  *(.tbyte)
>  *(.tcommon_byte)
>  *(.tdata)
>  *(.tbss)
>  *(.tcommon)
>                 0x00000678                __ep = ADDR (.tdata)
>
> .sdata          0x00000678        0x0 load address 0x00000678
>  *(.sdata)
>                 0x00008678                __gp = (ADDR (.sdata) + 0x8000)
>
> At linking i get:
> v850e-unknown-elf-ld -o hw2.elf \
>         -Map=hw2.map \
>         -Tv850.x \
>         -nostdlib \
>         main.o vectors.o
> v850e-unknown-elf-ld: address 0x678 of hw2.elf \
> section .tdata is not within region ram
>
> v850e-unknown-elf-ld: address 0x678 of hw2.elf \
> section .sdata is not within region ram
>
>
> I don't know why the address of .tdata and .sdata is set to its
> _load_ address and not to an address in RAM.  For .data it
> worked as expected.
>
> Of course i can send the sources, the ELF file and any other
> data that are needed to this list.
>
> For reference i attach the linker script and the two short source
> files to the end of this mail.
>
>
> Best regards,
> Torsten.
>
> v850.x
> OUTPUT_FORMAT("elf32-v850", "elf32-v850", "elf32-v850")
> OUTPUT_ARCH(v850)
> ENTRY(_start)
> SEARCH_DIR(.);
> EXTERN(__ctbp __ep __gp);
>
> MEMORY
> {
>   vect(rx)  : org = 0x00000000, len = 0x640
>   rom(rx)   : org = 0x00000640, len = 512k
>   ram(rwx)  : org = 0x03ffe000, len = 15k
>   stack(rw) : org = 0x03fffc00, len = 1k
> }
>
> SECTIONS
> {
>   .vect :
>   {
>     *(.vect)
>   } >vect
>
>   .zdata :
>   {
> 	*(.zdata)
> 	*(.zbss)
> 	*(reszdata)
> 	*(.zcommon)
>   } >ram
>
>   .rozdata ALIGN (4) :
>   {
> 	*(.rozdata)
> 	*(romzdata)
> 	*(romzbss)
>   } >rom
>
>
>   .text :
>   {
>     *(.text)
>     *(.text.*)
>     *(.gnu.warning)
>     *(.gnu.linkonce.t*)
>   } > rom
>   _etext = .;
>   PROVIDE (etext = .);
>
>   .call_table_data ALIGN (4) :
>   {
>     *(.call_table_data)
>   } > rom = 0xff
>   __ctbp = ADDR(.call_table_data);
>
>   .call_table_text :
>   {
>     *(.call_table_text)
>   } > rom
>
>   .data :
>   {
>     *(.data)
>     *(.data.*)
>     *(.gnu.linkonce.d*)
>     CONSTRUCTORS
>   } > ram AT > rom
>   .data1	: { *(.data1) } > rom
>
>   .gcc_except_table : { *(.gcc_except_table) } >rom
>   .got		: { *(.got.plt) *(.got) } >rom
>
>   .dynamic	: {
>     *(.dynamic)
>     . = ALIGN(2);
>     PROVIDE(__romdatastart = .); /* IF_ROCOPY */
>   } >rom
>
>
>   .tdata ALIGN(4) :
>   {
> 	*(.tbyte)
> 	*(.tcommon_byte)
> 	*(.tdata)
> 	*(.tbss)
> 	*(.tcommon)
>   } > ram AT > rom
>
>   __ep = ADDR(.tdata);
>
>
>   .sdata ALIGN (4) :
>   {
> 	*(.sdata)
>   } > ram AT > rom
>   __gp = ADDR(.sdata) + 0x8000;
>
>   .rosdata ALIGN (4) :
>   {
> 	*(.rosdata)
>   } >rom
>
>   .sbss :
>   {
> 	__sbss_start = .;
> 	*(.sbss)
> 	*(.scommon)
>   } >ram
>   _edata  = DEFINED (__sbss_start) ? __sbss_start : . ;
>   PROVIDE (edata = _edata);
>   .bss       :
>   {
> 	__bss_start = DEFINED (__sbss_start) ? __sbss_start : . ;
> 	__real_bss_start = . ;
> 	*(.dynbss)
> 	*(.bss)
> 	*(COMMON)
>   } >ram
>   _end = . ;
>   PROVIDE (end = .);
>
>   .comment 0		: { *(.comment) }
>
>   .stack :
>   {
> 	__stack = .;
> 	*(.stack)
>   } >stack
> }
>
>
>
> vectors.S:
> .global _start
> .global _main
>
>         .section .vect,"ax",@progbits
>
> .offset 0x00
>         jr      _start
>
>
>
> _start:
>         jr      _main
>
>
>
> main.c:
> int main(int argc, char** argv) {
>   volatile int i;
>   volatile unsigned char p;
>
>
>   while(1) {
>     p++;
>     for(i = 0; i < 1000; i++);
>   }
>
>   return 0;
> }