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flat assembler > DOS > sprintf for dos via fasmg, i need help to compile: mov ax,[b

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uor99



Joined: 04 Dec 2014
Posts: 41
sprintf for dos via fasmg, i need help to compile: mov ax,[b

Code:

;sprintf for dos via fasmg, i need help to compile: mov ax,[bp+dx]
;(https://board.flatassembler.net/topic.php?p=190878)
;
include '8086.inc'
include 'format/mz.inc'
macro stdcall proc,args&
        iterate argargs
                indx 1+%%-%
                mov bx,arg
                push bx
        end iterate
        call proc
end macro
entry code:start        ; program entry point
stack 100h      ; stack size
        segment code
start:
        push cs
        pop ds
        call main
        mov ah,4ch
        int 21h
; sprintf(soutput, sformat, [args])
; sformat: string containing the pattern of the output string
;%s: string
;%d: decimal number
;%h: hexadecimal number in lower case
;%h: hexadecimal number in upper case
;
;%d, %h and %h also accepts ":[number of fixed digits]"
;the number in the square brackets should then be in[0..9] and equal one less the number of fixed digits...
; soutput: pointer to buffer which will receive the output string
; [args]: ...
;
; alpha_addition db 0
; digit_count db 0
; put these two variables in the data section:
max_dx equ 8
sprintf:
        ;enter 0,0
        push bp
        mov bp,sp
        mov dx,max_dx
        mov di,[bp+4]
        mov si,[bp+6]
        
        push dx
        mov dx,si
        ;call _tips
        pop dx
 .loop:
        lodsb
        cmp al,"%"
        je .format
        stosb
        test al,al
        jnz .loop
 .done:
        xor ax,ax
        jmp .finish
 .error:
        or ax,-1
 .finish:
        ;leave
        mov spbp
        pop bp
        
        pop ax
        sub dx,max_dx/2;8
        add sp,dx
        jmp ax
 .format:
        lodsb
        cmp al,"%"
        jne .not_percent
        stosb
        jmp .loop
 .not_percent:
        mov [digit_count],0
        push ax
        cmp byte [si],":"
        jne .not_extra
        lodsb
        cmp byte [si],":"
        je .not_extra
        lodsb
        cmp al,"0"
        jl .error
        cmp al,"9"
        jg .error
        sub al,2fh
        mov [digit_count],al
 .not_extra:
        pop ax
        cmp al,"s"
        je .string
        cmp al,"h"
        je .number.lhex
        cmp al,"h"
        je .number.uhex
        cmp al,"d"
        jne .error
 .number.dec:
        mov bx,10
        call .number
        jmp .loop
 .number.lhex:
        mov byte [alpha_addition],27h
        mov bx,16
        call .number
        jmp .loop
 .number.uhex:
        mov byte [alpha_addition],7
        mov bx,16
        call .number
        jmp .loop
 .number:
        push bx
        mov bx,bp
        add bx,dx
        mov ax,[bp+dx];[bp+dx]
        pop bx
        add dx,max_dx/4;4
        push dx
        xor cx,cx
 .number.loop:
        xor dx,dx
        div bx
        push dx
        inc cx
        test ax,ax
        jnz .number.loop
        cmp [digit_count],0
        je .number.putchar
        push cx
        mov ax,cx
        mov cl,byte [digit_count];;;
        sub cx,ax
        jz .number.prefix.end
        js .number.prefix.end
        mov al,"0"
 .number.prefix:
        stosb
        loop .number.prefix
 .number.prefix.end:
        pop cx
 .number.putchar:
        pop ax
        add al,30h
        cmp al,39h
        jle .number.putchar.nonalpha
        add al,[alpha_addition]
 .number.putchar.nonalpha:
        stosb
        loop .number.putchar
        pop dx
        ret
 .string:
        push si
        push bx
        mov bx,bp
        add bx,dx
        mov si,[bp+dx];[bp+dx]
        pop bx
        add dx,max_dx/4;4
 .string.loop:
        lodsb
        test al,al
        jz .string.end
        stosb
        jmp .string.loop
 .string.end:
        pop si
        jmp .loop
main:
        push bp
        mov bpsp
        ;
        stdcall sprintf,soutput,sformat,hi,16,start2,start
        add sp,12
        ;
        mov dx,soutput
        mov ah,9
        int 21h
        ;
        mov dx,2
        add dx,30h
        mov ah,2
        int 21h
        mov spbp
        pop bp
        ret

;segment data
        alpha_addition db 0
        digit_count db 0
        sformat db "%s! %d-lol",13,10
                db "%s = offset: 0x%h:7$"
        hi      db "hi$"
        start2  db "start$"
        soutput rb 100h


Post 04 Oct 2016, 23:36
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 15233
Location: 1I/╩╗Oumuamua
Re: sprintf for dos via fasmg, i need help to compile ...

uor99 wrote:
i need help to compile: mov ax,[bp+dx]

DX cannot be used as an addressing register. Only SI, DI, BP and BX.
Post 05 Oct 2016, 09:23
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Tomasz Grysztar
Assembly Artist


Joined: 16 Jun 2003
Posts: 6628
Location: Krak├│w, Poland
Also, even not all combination of these four are possible. Each of them can be used individually and there are just four combinations of two that are allowed: BX+SI, BX+DI, BP+SI and BP+DI.
Post 05 Oct 2016, 09:39
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