linker problem

[Martin Knappe]

hi

i have a problem that has more to do with the gnu linker, but havent 
found an appropriate forum, so i thought i'd post it here; if someone 
can help me, good, if not, just ignore... :-)

suppose i have the following object file:

//begin main.o
main.o:     file format elf32-i386

Disassembly of section .data:

00000000 <.data>:
  0:   ff                      (bad) 
  1:   ff                      (bad) 
  2:   ff                      (bad) 
  3:   ff                      .byte 0xff
Disassembly of section .text:

00000000 <.text>:
  0:   06                      push   %es
  1:   00 00                   add    %al,(%eax)
  3:   00 06                   add    %al,(%esi)
  5:   00 00                   add    %al,(%eax)
  7:   00 48 65                add    %cl,0x65(%eax)
  a:   6c                      insb   (%dx),%es:(%edi)
  b:   6c                      insb   (%dx),%es:(%edi)
  c:   6f                      outsl  %ds:(%esi),(%dx)
  d:   2e 00 00                add    %al,%cs:(%eax)
Disassembly of section .text:

00000000 <start>:
  0:   55                      push   %ebp
  1:   89 e5                   mov    %esp,%ebp
  3:   68 08 00 00 00          push   $0x8
  8:   e8 fc ff ff ff          call   9 <start+0x9>
  d:   89 ec                   mov    %ebp,%esp
  f:   5d                      pop    %ebp
 10:   c3                      ret

//end main.o


I link this file together with two other object files:

ld main.o video.o utilities.o -e start -N -o boot.bin --oformat binary 
-T script

The linker script is as follows:

//begin script

SECTIONS
{
 . = 0x0;
 .text : { *(.text) }
 .data : { *(.data) }
 .bss : { *(.bss) }
}

//end script

When I disassemble the linked result, I get this:


//begin
00000000  06                push es
00000001  0000              add [eax],al
00000003  0006              add [esi],al
00000005  0000              add [eax],al
00000007  004865            add [eax+0x65],cl
0000000A  6C                insb
0000000B  6C                insb
0000000C  6F                outsd
0000000D  2E0000            add [cs:eax],al
00000010  55                push ebp
00000011  89E5              mov ebp,esp

...and so on
//end

You can see clearly here that what is placed right at the start of the 
linked result is the code that comes in section .text of the object file 
just before the function "start" EVEN THOUGH I have specified in my 
linker command that "start" be the entry point. The problem is that this 
part of section .text is not only NOT supposed to be the start of my 
code, but that it is really READONLY data placed into the .text section 
by the compiler for some reason. Can I do anything about this? Is there 
a way to make the linker place this AFTER all executable code (i.e. 
where data and bss are  placed)...

Thanks

Martin