programme header

[ishare]

  when product a .so liberary , if there is not a programme header in the linker script file,
  will the linker automaticlly generate a deault one for use  ?
 
  If I write the programme header manully , need I write it before writing  section command ?
  like this :
 
      PHDRS
      {
           .....
      } 

      SECTIONS
      {
           .....
      }
  


  thanks!