[GOLD] -Ttext does not relocate as expected

[ryan]

I see. Thanks Ian! It seems like my example only has one text section, so what
could be the other sections occupying the first 0x1000 offset?

-Ryan
On Wed, Mar 20, 2013 at 5:33 PM, Ian Lance Taylor <iant@google.com> wrote:
> On Wed, Mar 20, 2013 at 5:21 PM, ryan <stdstack@gmail.com> wrote:
>> Not sure whether this is a bug or not. When I'm writing a simple hello
>> world boot loader, I tried to relocate the text section to 0x7c00 for
>> convention. The assembly code is attached. I used the following
>> command to compile it:
>>> gcc -m32 -nostdinc -c -o boot.o boot.S
>>> ld -m elf_i386 -N -e start -Ttext 0x7c00 -o boot.out boot.o
>>> objdump -S boot.out > boot.asm
>>> ...
>>
>> It doesn't work as expected. Then I checked boot.asm the actual start
>> address is 0x8c00 instead of 0x7c00.
>>> Disassembly of section .text:
>>> 00008c00 <start>:
>>>    8c00: fc                   cld
>>>    8c01: 31 c0                 xor    %eax,%eax
>>>    ...
>>
>> It took me a while to realize in my system, I replaced the default
>> `ld' with `ld.gold'. So `ld' in the above command is actually
>> `ld.gold'. After I changed it back to use the default `ld', the start
>> address become 7c00 as expected. Does anyone has a clue why it's like
>> this?
>
>
> For GNU ld the -Ttext option sets the address of the .text section.
> For gold the -Ttext option sets the address of the text segment.  If
> your .text section is not the first section in your text segment, then
> the results will differ.
>
> Ian