Re: Re: How to inform the linker not to produce any data for a .bsssection?

["PRC" <panruochen at gmail dot com>]

There is a global static array in my code:
static char cmd_buffer[1024*64] __attribute__(( section(".mydata") ));

And inform the linker to put it in section ".bss":
.bss :
	{
 	 	*(.bss)
  	 	*(COMMON)
  	 	*(.mydata)
	}

mips-elf-objdump -h a.out 
-------------------------------------------------------------------
  3 .bss          00010620  81413898  81413898  00003898  2**3
                  ALLOC
  4 .reginfo      00000018  00000000  00000000  00013eb8  2**2
                  CONTENTS, READONLY, LINK_ONCE_SAME_SIZE
------------------------------------------------------------------
The difference between sections ".bss" and ".reginfo" is almost 64K,
which is just the size of the buffer `cmd_buffer`. And I check the
output file, and find there are lots of zero starting from the offset
0x3898. It seems the linker puts 64K zeros in the section ".bss".


 
On Sun, Dec 09, 2007 at 10:50:50AM +0800, PRC wrote:
>   2 .bss          00000620  811eeb00  811eeb00  00002b00  2**3
>                   ALLOC

> The linker create a real '.bss' section in the output ELF file and
> store some data inside the section, which greatly increase the size
> of the ELF file. 

No, it didn't.  It takes up no space in the file because it does not
have the CONTENTS flag.

-- 
Daniel Jacobowitz
CodeSourcery