;;; -------------------------------------------------------------------
;;; ledON.asm
;;; D. Thiebaut
;;; This program turns the LED On on the Arduino stamp.
;;; The program simply writes an \r -terminated string to /dev/ttyUSB0
;;; that simply puts a 1 on Digital Pin 13. The string is "w d 13 1\r"
;;;
;;;
;;; nasm -f elf ledON.asm
;;; nasm -f elf asm_io.asm
;;; gcc -m32 -o ledON driver.c asm_io.o ledON.o
;;; (use -m32 on 64-bit machines)
;;;
;;; Without the asm_io.* and driver.c wrappers, then link with
;;; ld -melf_i386 ledON.o -o ledON
;;; (use -melf_i386 on 64-bit machines)
;;;
;;; To Execute:
;;;
;;; ./ledON
;;;
;;; -------------------------------------------------------------------
%include "asm_io.inc"
%assign EXIT 1
%assign OPEN 5
%assign CLOSE 6
%assign READ 3
%assign CREATE 8
%assign WRITE 4
%assign STDOUT 1
%assign O_CREAT 64
%assign O_RDONLY 0
%assign O_WRONLY 1
%assign O_APPEND 1024
%assign O_RDWR 2
%assign S_IRUSR 00400q
%assign S_IWUSR 00200q
%assign S_IXUSR 00100q
;;; ____ _
;;; | _ \ __ _| |_ __ _
;;; | | | |/ _` | __/ _` |
;;; | |_| | (_| | || (_| |
;;; |____/ \__,_|\__\__,_|
;;;
section .data
errorMsg db "Error accessing file!",0x0a, 0
errorMsg1 db "Error opening file!",0x0a, 0
usb db "/dev/ttyUSB0",0
handle dd 0
noRead dd 0
msg db "w d 13 1", 0x0d
msgLen equ $-msg
section .bss
%assign MAXBUF 100
buffer resb MAXBUF
;;; ____ _
;;; / ___|___ __| | ___
;;; | | / _ \ / _` |/ _ \
;;; | |__| (_) | (_| | __/
;;; \____\___/ \__,_|\___|
;;;
section .text
global asm_main
asm_main:
;;; open file, write string, close file...
mov ebx, usb
call openFile
mov dword[handle], eax
mov ebx, [handle]
mov ecx, msg
mov edx, msgLen
call writeFile
mov ebx, dword[handle]
call closeFile
;;; we're done!
ret
;;; if there's a problem, we exit right away
exit:
mov eax,EXIT
mov ebx,0
int 0x80 ; final system call
;;; --------------------------------------------------------
;;; openFile
;;; put address of ASCIIZ file name in ebx
;;; handle returned in eax
;;; --------------------------------------------------------
openFile:
mov eax, OPEN
mov ecx,O_WRONLY | O_APPEND ; mode for opening file
mov edx,S_IRUSR | S_IWUSR
int 0x80
test eax,eax ; test for errors
jns doneOpenFile
mov eax, errorMsg1
call print_string
jmp exit
doneOpenFile:
ret ; handle in eax
;;; --------------------------------------------------------
;;; closeFile: the handle must be in ebx on entry.
;;; Closes the file
;;; --------------------------------------------------------
closeFile:
mov eax,CLOSE
int 0x80
ret
;;; --------------------------------------------------------
;;; readFile: on entry:
;;; handle in ebx
;;; buffer address in ecx
;;; max buffer length in edx
;;; on exit: number of chars read in eax
;;; --------------------------------------------------------
readFile:
mov eax,READ
int 0x80
test eax,eax
jns doneReadFile
mov eax, errorMsg
call print_string
jmp exit
doneReadFile:
ret
;;; --------------------------------------------------------
;;; writeFile:
;;; on entry:
;;; handle is in ebx
;;; buffer address is in ecx,
;;; number of chars is in edx.
;;; --------------------------------------------------------
writeFile:
mov eax,WRITE
int 0x80
test eax,eax
jns doneWriteFile
mov eax, errorMsg
call print_string
jmp exit
doneWriteFile:
ret
