When I try to build my assembly code I run into this error:
App.o: in function `_start':
App.asm:(.text+0x8c): relocation truncated to fit: R_386_16 against `.bss'
I compile it using this 2 command:
nasm -f elf32 App.asm
ld -m elf_i386 App.o /usr/local/bin/utils.o -o App
Then I run the App file.
This is my code:
App.asm
%include 'Fun.asm'
%include 'utils.nasm'
section .data
V dw 2,-10,13,5,0,1,-9,3
n equ ($-V)/2
d dw 7
section .bss
r resw 1
section .text
global _start
_start:
push V
push dword n
push word [d]
push r
call fun
printw r
exit 0
Fun.asm
section .data
VV equ 18
nn equ 14
dv equ 12
rr equ 8
section .bss
g resb 1
section .text
global fun
fun:
push ebp
mov ebp, esp
pushad ;Inizio procedura
mov byte [g], 1
mov eax, [ebp+VV] ;EAX(V)
mov bx, [ebp+dv] ;BX(d)
mov edi, [ebp+nn] ;EDI(n)
xor dx, dx ;DX(Somma)
loop1:
cmp edi, 0 ;If n<=0 Fine
jle fine
cmp word [eax], 0 ;If V[i]==0 Cambia gruppo
je cmb_grp
cmp [eax], bx ;If V[i]>d Esterno
jg esterno
neg bx ;BX=-d
cmp [eax], bx ;If V[i]<-d Esterno
jl esterno
cmp byte [g], 1 ;If g==1 Avanti
je avanti
add dx, [eax] ;Somma+=V[i]
jmp avanti
esterno:
cmp byte [g], 2 ;If g==2 Avanti
je avanti
add dx, [eax] ;Somma+=V[i]
jmp avanti
cmb_grp:
mov byte [g], 2 ;Passimo a gruppo 2
mov [ebp+rr], dx ;Salviamo somma gruppo 1
xor dx, dx ;Somma=0
jmp avanti_
avanti:
neg bx ;BX=d
avanti_:
add eax, 2 ;i++
dec edi ;n--
jmp loop1
fine:
sub [ebp+rr], dx ;Calcolo risultato
popad ;Fine procedura
pop ebp
ret 14
utils.nasm
; ===============================================================================================
;
; utils.nasm
;
; ===============================================================================================
;
; Libreria di macro di utilità generale. Di seguito si riporta l'elenco dei comandi
; disponibili, la sintassi e la relativa descrizione.
;
; -----------------------------------------------------------------------------------------------
; printd <dword> stampa a video una double word (registro, memoria, immediato)
; Sintassi specifica:
; printd dword <immediato_32_bit>
; printd dword [<indirizzo>]
; printd <registro_32_bit>
; -----------------------------------------------------------------------------------------------
; printw <word> stampa a video una word (reg, mem, imm)
; Sintassi specifica:
; printw word <immediato_16_bit>
; printw word [<indirizzo>]
; printw <registro_16_bit>
; -----------------------------------------------------------------------------------------------
; printb <byte> stampa a video un bye (reg, mem, imm)
; Sintassi specifica:
; printb byte <immediato_8_bit>
; printb dword [<indirizzo>]
; printb <registro_8_bit>
; -----------------------------------------------------------------------------------------------
; prints <str>,<len> stampa a video la stringa di lunghezza <len>
; posta in memoria a partire dall'indirizzo <str>
; -----------------------------------------------------------------------------------------------
; printregs mostra il contenuto dei registri generali a 32 bit
; -----------------------------------------------------------------------------------------------
; print<reg> mostra il contenuto del registro a 32 bit <reg>
; dove <reg> in {eax, ebx, ecx, edx, esi, edi, ebp, esp}
; -----------------------------------------------------------------------------------------------
; format_dec imposta il formato di output a DECIMAL (default)
; -----------------------------------------------------------------------------------------------
; format_udec imposta il formato di output a UNSIGNE DECIMAL
; -----------------------------------------------------------------------------------------------
; format_bin imposta il formato di output a BINARY
; -----------------------------------------------------------------------------------------------
; format_hex imposta il formato di output a HEXADECIMAL
; -----------------------------------------------------------------------------------------------
; cr_on abilita a capo nelle stampe (default)
; -----------------------------------------------------------------------------------------------
; cr_off disabilita a capo nelle stampe
; -----------------------------------------------------------------------------------------------
; exit <code> termina il programma con codice d'uscita <code>
; ===============================================================================================
;
; Per utilizzare i comandi nel proprio sorgente assembly:
; 1) Includere utils.nasm nel proprio file sorgente con la direttiva:
; %sseutils "utils.nasm"
; 2) Includere nel link il file oggetto utils.o:
; ld -m elf_i386 <file>.o utils.o -o <file>
;
section .data
seax db 'eax = ['
leax equ $-seax
sebx db 'ebx = ['
lebx equ $-sebx
secx db 'ecx = ['
lecx equ $-secx
sedx db 'edx = ['
ledx equ $-sedx
sesi db 'esi = ['
lesi equ $-sesi
sedi db 'edi = ['
ledi equ $-sedi
sebp db 'ebp = ['
lebp equ $-sebp
sesp db 'esp = ['
lesp equ $-sesp
send db ']'
scr db 10
lend equ 2
oldcr db 1
extern format
extern cr
extern sprintd
extern buf
extern buflen
%macro exit 1
mov eax, 1
mov ebx, %1
int 80h
%endmacro
%macro prints 2
pushfd
pushad
mov eax, 4
mov ebx, 1
mov ecx, %1
mov edx, %2
int 80h
popad
popfd
%endmacro
%macro printcr 0
prints scr, 1
%endmacro
%macro printbuf 0
prints buf, [buflen]
%endmacro
%macro cr_on 0
mov [cr], byte 1
%endmacro
%macro cr_off 0
mov [cr], byte 0
%endmacro
%macro cr_save 0
push eax
mov al, [cr]
mov [oldcr], al
pop eax
%endmacro
%macro cr_restore 0
push eax
mov al, [oldcr]
mov [cr], al
pop eax
%endmacro
%macro format_dec 0
mov [format], byte 0
%endmacro
%macro format_udec 0
mov [format], byte 1
%endmacro
%macro format_bin 0
mov [format], byte 2
%endmacro
%macro format_hex 0
mov [format], byte 3
%endmacro
%macro printd 1
pushfd
pushad
push dword 32
push %1
call sprintd
add esp, 8
printbuf
popad
popfd
%endmacro
%macro printw 1
pushfd
pushad
push dword 16
mov ax, %1
movsx eax, ax
push eax
call sprintd
add esp, 8
printbuf
popad
popfd
%endmacro
%macro printb 1
pushfd
pushad
push dword 8
mov al, %1
movsx eax, al
push eax
call sprintd
add esp, 8
printbuf
popad
popfd
%endmacro
%macro printeax 0
cr_save
cr_off
prints seax, leax
printd eax
prints send, lend
cr_restore
%endmacro
%macro printebx 0
cr_save
cr_off
prints sebx, lebx
printd ebx
prints send, lend
cr_restore
%endmacro
%macro printecx 0
cr_save
cr_off
prints secx, lecx
printd ecx
prints send, lend
cr_restore
%endmacro
%macro printedx 0
cr_save
cr_off
prints sedx, ledx
printd edx
prints send, lend
cr_restore
%endmacro
%macro printesi 0
cr_save
cr_off
prints sesi, lesi
printd esi
prints send, lend
cr_restore
%endmacro
%macro printedi 0
cr_save
cr_off
prints sedi, ledi
printd edi
prints send, lend
cr_restore
%endmacro
%macro printebp 0
cr_save
cr_off
prints sebp, lebp
printd ebp
prints send, lend
cr_restore
%endmacro
%macro printesp 0
cr_save
cr_off
prints sesp, lesp
printd esp
prints send, lend
cr_restore
%endmacro
%macro printregs 0
cr_save
printcr
printeax
printebx
printecx
printedx
printesi
printedi
; printebp
; printesp
cr_restore
%endmacro
What could it be?
The problem is the line:
printw r
Due to the macro %macro printw 1 in utils.asm, that line will actually cause the following code:
...
mov ax, r
...
I don't use nasm, but I assume that nasm interprets this line as:
"Load the address of r into the register ax."
This is not possible because the address is a 32-bit value but ax is only 16 bits wide.
As I have already written, I don't know nasm. Therefore I cannot tell you how you can load the value stored at r into the register ax.
However, in other assemblers that I know, the following line should do the job:
printw [r]