LINKER.LD:

ENTRY(start)

SECTIONS
{
	. = 1M;

	.boot :
	{
		KEEP(*(.multiboot_header))
	}

	.text :
	{
		*(.text)
	}
}

objdump -D kernel/kernel.bin

kernel/kernel.bin:     file format elf64-x86-64


Disassembly of section .boot:

0000000000100000 <header_start>:
  100000:       d6                      (bad)
  100001:       50                      push   %rax
  100002:       52                      push   %rdx
  100003:       e8 00 00 00 00          call   100008 <header_start+0x8>
  100008:       18 00                   sbb    %al,(%rax)
  10000a:       00 00                   add    %al,(%rax)
  10000c:       12 af ad 17 00 00       adc    0x17ad(%rdi),%ch
  100012:       00 00                   add    %al,(%rax)
  100014:       08 00                   or     %al,(%rax)
        ...

Disassembly of section .text:

0000000000100000 <start>:
  100000:       c7 05 00 80 0b 00 4f    movl   $0x2f4b2f4f,0xb8000(%rip)        # 1b800a <header_end+0xb7ff2>
  100007:       2f 4b 2f
  10000a:       f4