BITS 64

%define __NR_read 3
%define __NR_write 4

GLOBAL  _start

SECTION .bss

%define bufsize 10240
buffer  resb    bufsize

SECTION .text

_start:

        mov     eax,__NR_read   ; "read" function number
        xor     ebx,ebx         ; console read file descriptior (0)
        mov     ecx,buffer      ; buffer address
        mov     edx,bufsize     ; buffer size
        int     0x80            ; read from console (returns read bytes count in eax)

        mov     edx, 2048    ; number of bytes to write
        mov     eax,__NR_write  ; "write" function number
        mov     ebx,1           ; console write file descriptior
        ; buffer address (ecx) is not changed
        int     0x80            ; write to console