what is '=0' after a section in linker script?

Question

I think I knew this but forgot.
What does the '=0' sign after the section represent in linker script?

  .text :
  {
    *bootcode.o(boot)
    *vectors.o(vectors)
    *(.text) /* remainder of code */
  } =0

Answer 1

Including =fill in a section definition specifies the initial fill value for that section. (=0 in your example). manual