How to inform the linker not to produce any data for a .bss section?

["PRC" <panruochen@gmail.com>]

Here is my link script:

--------------------------------------------------------------------
OUTPUT_ARCH(mips)

SECTIONS
{
	.text 0x811ed000  :
	{
		_dstart = ABSOLUTE(.) ;	/* Start of code and data	*/
		*(.libc)
		*(.text*)
		*(.rodata*)
	}

	.data :
	{
		*(.data)
	}

	.sbss :
 	{
		*(.sbss)
		*(.scommon)
	}

 	.bss :
	{
 	 	*(.bss)
  	 	*(COMMON)
	}
 	
 	_dend = ABSOLUTE(.) ;	/* end of code and data	*/
}
--------------------------------------------------------------------
and mips-elf-objdump -h a.out shows:

a.out:     file format elf32-littlemips

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         00001ab4  811ed000  811ed000  00001000  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  1 .data         0000004c  811eeab4  811eeab4  00002ab4  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  2 .bss          00000620  811eeb00  811eeb00  00002b00  2**3
                  ALLOC
  3 .reginfo      00000018  00000000  00000000  00002b00  2**2
                  CONTENTS, READONLY, LINK_ONCE_SAME_SIZE
  4 .pdr          000003c0  00000000  00000000  00002b18  2**2
                  CONTENTS, READONLY
  5 .mdebug.abi32 00000000  00000000  00000000  00002ed8  2**0
                  CONTENTS, READONLY

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. 

How can I do to inform the linker don't produce any data for the .bss section?

My linker is:
mips-elf-ld -v
GNU ld version 2.15

BTW, I'd like to know how to get a minimal ELF file. As you see, the offset of the
first section is 0x1000, which means the size of the ELF header is 4K in bytes. 
Is there a way to cut off the size of the header?