gas-940814 ld bugs

gas-940814 ld bugs

[H.J. Lu]

gas-940814 configured for i486-linux. If I do

ld -x -Ttext 5ffff000 -Tdata 6008e000 foo.o

the size of the output file is ridiculous. I got

-rwxr-xr-x   1 hjl      isl          8367 Aug 15 01:54 a.out
text    data    bss     dec     hex     filename
4064    4096    0       8160    1fe0    a.out

But I am looking for about 0x8e000 bytes.


H.J.
-------foo.c----
int bar= 100;

void
foo ()
{
  return;
}

Re: gas-940814 ld bugs

[Ian Lance Taylor]

   From: hjl@nynexst.com (H.J. Lu)
   Date: Mon, 15 Aug 94 1:33:47 EDT

   gas-940814 configured for i486-linux. If I do

   ld -x -Ttext 5ffff000 -Tdata 6008e000 foo.o

   the size of the output file is ridiculous. I got

   -rwxr-xr-x   1 hjl      isl          8367 Aug 15 01:54 a.out
   text    data    bss     dec     hex     filename
   4064    4096    0       8160    1fe0    a.out

   But I am looking for about 0x8e000 bytes.

When you use -Ttext and -Tdata, the linker will link the code as if
the .text and .data sections start at the given address.  It will also
tell BFD to store the given VMA with the section.  It will not insert
extra zero bytes.

The problem, of course, is that a.out has no way to store the starting
VMA of a section.  This is one of several disadvantages of the a.out
format.  The solution is to either use a different object file format,
or to modify the linker script along the lines of
    .text 0x1020 {
	. = 0x5ffff000
	*(.text)
    }

Ian