;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;rws.s                                                                  ;;
;;written by, soni.malik@gmail.com                                       ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

global _readSectors
global _writeSectors

_readSectors: 

       ;The usual creation of stack frame.
       push     bp
       mov      bp, sp

       ;Clobbered registers
       push     ax
       push     bx
       push     cx
       push     dx
       push     es

       ;The register pair ES:BX wil hold the address of the buffer  
       ;where the sector/s will be read in.
       mov      bx, [bp + 0x06]
       mov      ax, [bp + 0x08]
       mov      es, ax
       ;Other service parameters. 
       mov      ah, 0x02        ;Int 0x13 service number.
       mov      al, [bp + 0x0e] ;Number of sectors to read. 
       mov      ch, [bp + 0x0d] ;Track/cylinder number.
       mov      cl, [bp + 0x0c] ;Starting sector number.
       mov      dh, [bp + 0x0a] ;Head number.
       mov      dl, [bp + 0x0b] ;Drive number.
       int      0x13            

       ;Copy the return status.
       mov      bx, [bp + 0x10]
       mov      [bx], ax
       
       ;Restoring all the clobbered registers.
       pop      es
       pop      dx
       pop      cx
       pop      bx
       pop      ax
       mov      sp, bp
       pop      bp
       
       retf

_writeSectors: 

       push     bp
       mov      bp, sp


       mov      sp, bp
       pop      bp
       
       retf