Relocating Data Sections

["Wood Mark" <mjwood2 at hotmail dot com>]

I am writing a program to be used in an powerpc embedded system.  I have 
compiled the appropriate cross compiler and including binutils-2.13.92.

I am trying to place my .text section at 0xff400000.  Since I can only load 
to flash, I am also trying to load my .data section directly after my .text 
section, but have it relocated to 0xe80000 during program initialization.

Upon reading the ld documentation, I was under the impression this could be 
accomplished by using the AT command as follows:

--- start linker script ---
OUTPUT_FORMAT("elf32-powerpc", "elf32-powerpc",
                          "elf32-powerpc")
OUTPUT_ARCH(powerpc)

PROVIDE (__stack = 0x00E00000);
MEMORY
{
  flash  : ORIGIN = 0xFF400000, LENGTH = 0xFFFFF
  ram   : ORIGIN = 0x00E80000, LENGTH = 0x7FFF
}

SECTIONS
{
 .text : { *(.text) _etext = .; } > flash
 .data : AT ( ADDR( .text ) + SIZEOF( .text ) )
      { _data = . ; *(.data); _edata = . ; }
}
--- end linker script ---

If I use this linker script, the resulting ELF file shows the LMA of the 
.data section to be 0xff4041bc and the VMA of the .data section at 
0x00e80000.

However, when I load this application on the hardware, before the code is 
even run, I find the .data section at 0xe80000.  Interestingly enough, it is 
not located at 0xff4041bc as well.  This is problematic because everything 
at 0xe80000 is zeroed before execution by crt0.  Am I wrong in believing 
that crt0 is supposed to copy everything from the _etext through _edata and 
place it at _data?

Thanks for any help,
     Mark Wood

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