Mail Archives: djgpp/1997/04/15/09:50:47
| From: | beppu AT rigel DOT oac DOT uci DOT edu (John Beppu)
|
| Newsgroups: | comp.os.msdos.djgpp
|
| Subject: | NASM Propaganda
|
| Date: | 15 Apr 1997 10:32:01 GMT
|
| Organization: | University of California, Irvine
|
| Lines: | 324
|
| Message-ID: | <5ivlf1$eif@news.service.uci.edu>
|
| NNTP-Posting-Host: | rigel.oac.uci.edu
|
| To: | djgpp AT delorie DOT com
|
| DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
|
[NASM Propaganda]
If you would like to
|
+-- use assembly under x86 Linux
+-- use assembly with DJGPP
+-- assemble MMX instructions
+-- assemble PPro instructions
+-- be able to use an x86 assembler on a non-x86 platform
+-- output various object file formats such as
|
+-- bin
+-- a.out
+-- coff
+-- elf
+-- as86
+-- obj
+-- win32
+-- rdf
and are willing to pay 0 dollar$/pounds/en/etc. for such an
assembler, NASM might be for you. If you already know TASM or
MASM syntax, then moving to NASM will not be hard. If you are
not comfortable with the AT&T assembly syntax, now you have an
alternative. If you are afraid that your current assembler
will not keep up with current processors, NASM comes with
complete source so adding support for new instructions should
not be /too/ difficult.
[The Shortcomings]
At the moment, NASM lacks
|
+-- macro support
| |
| +-- use a preprocessor like "cpp" or "m4" instead
|
+-- an easy way to align data
|
+-- hand-align or try the kludge mentioned in docs
So, if you have been spoiled by macros (Randy Hyde ;-), or are
extremely picky about data alignment, NASM may disappoint
you.
However, these shortcomings can be overcome, and future releases
of NASM will probably address these issues.
[In Conclusion]
I ask that anyone who hasn't given NASM a chance to please
do so. NASM is a very usable assembler.
NASM binaries are small, so please keep it around even if you
don't want to use it.
NASM is another fine product from the UK.
ftp://sunsite.unc.edu/pub/Linux/devel/lang/assemblers/nasm-0.94.tar.gz
ftp://wcarchive.cdrom.com/pub/simtelnet/msdos/asmutl/nasm093s.zip
[Peace Offering]
[note]
(I was going to cross-post at first, but the thought of
Nudds polluting comp.os.msdos.djgpp made me reconsider.)
I assume most of you comp.lang.asm.x86 folk still use DOS,
so here's a little .com file you can test NASM out with.
If you've got a (286 and a VGA) or better, and if you still
use text-mode in DOS, you don't have to use the same, old,
boring colors anymore. (yay.) This will also work with the
Win95 dos shell.
I'm a Linux user, but I must give respect
to the people at Microsoft responsible for the dos shell,
because they did a great job. I was surprised to see the
EGA and VGA port accesses being caught and emulated within
the dos shell. (When will DOSEMU be able to do this?! ;-)
If you don't have "cpp", just get rid of all the C/C++ styled
comments. I didn't use any #define statements, because I was
a bit worried about the availability of "cpp". I didn't want
people to be bothered to get the DJGPP package which contains
the DOS port of "cpp".
--8<-Makefile-----------------------------------------------------------------
all : setpal.com
setpal.com : setpal.s
nasm -o setpal.com setpal.s
setpal.s : setpal.asm
cpp -P setpal.asm setpal.s
--8<-setpal.asm---------------------------------------------------------------
[bits 16]
[section .text]
[org 100h]
coder equ beppu
// startUP
xor ax,ax
mov bp,argv
mov [argv+7],ax ; setup for .length_check
mov di,arg_buffer
mov bx,000Dh
mov cx,63
call _clP_save
push ds
pop es
/* unmodular Philip-styled x86 asm (forgive me)
usage: setpal 000f021f
-+-r-g-b
| | | + ( blue ) -+
| | +-- ( green ) | hexadecimal,
| +---- ( red ) | please (no upper case)
+------ ( palette entry ) -+
%% :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: */
_setpal:
// Only one parameter desired.
mov di,parser_table
cmp cx,byte 1
mov ax,0ffffh
jne near .end
// Generate parser table.
mov cx,128
mov bx,di
xor dx,dx
xor bp,bp
rep stosw
mov [bx+30h],bp ; 0,1
mov si,[argv]
mov [bx+32h],bp ; 2,3
mov [bx+34h],bp ; 4,5
mov [bx+36h],bp ; 6,7
mov [bx+38h],bp ; 8,9
mov ax,[si+7]
mov [bx+61h],dl ; a,
mov [bx+62h],bp ; b,c
cmp ah,1
mov [bx+64h],bp ; d,e
mov [bx+66h],dl ; f
sbb bp,bp
// Parse parameter for validity
// There must be exactly 8 characters within
// the subset of { '0'..'9' && 'a'..'b' |
.length_check:
xor bx,bx
and ax,bp
jz near .end
mov di,parser_table
mov cx,8
xor ax,ax
.validity_check:
mov bl,[si]
inc si
mov dl,[bx+di]
or ax,dx
dec cx
jnz .validity_check
mov dx,0202h
mov cx,0100h
mov bx,parser_table
test ax,ax
jnz near .end
// Turn parser_table into a conversion table
// using poor man's MMX
mov [bx+30h],cx ; 0,1
add cx,dx
mov [bx+32h],cx ; 2,3
add cx,dx
mov [bx+34h],cx ; 4,5
add cx,dx
mov [bx+36h],cx ; 6,7
add cx,dx
mov [bx+38h],cx ; 8,9
add cx,dx
mov [bx+61h],cl ; a
add cx,0101h
mov [bx+62h],cx ; b,c
add cx,dx
mov [bx+64h],cx ; d,e
inc ch
mov [bx+66h],ch ; f
// Convert parameter ; si == argv[1]
mov si,[argv]
sub sp,byte 4 ; a stackframe?
mov di,bx
mov bp,sp
xor bx,bx
xor ax,ax
mov cx,4
.convert
mov bl,[si]
mov al,[bx+di]
sal al,4
mov bl,[si+1]
add si,byte 2
mov dl,[bx+di]
or al,dl
mov [bp],al
inc bp
dec cx
jnz .convert
mov bp,sp ; indeed. a stackframe.
// Set palette
mov dx,3c8h
mov al,[bp]
lea si,[bp+1]
mov cx,3
out dx,al
inc dx
rep outsb
add sp,byte 4 ; bye-bye, stackframe.
.end:
retn
/* Proc clP_save far (8086+,DOS,realmode) ::::::::::::::::::::::::::::::::::
IN: OUT:
DS : seg Program Segment Prefix CX : # of parameters
ES : seg of buffers
DI : offset parameter_buffer | relative
BP : offset offset_buffer | to ES
CX : (len.b(param_b) - 1)
BL : (len.w(offset_b)) offset param_b : filled
BH : string termination byte offset offset_b : filled
registers : ax bx cx dx di si bp (used)
%% :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: */
_clP_save:
cld
mov si,80h ; # of chars on command-line
mov al,[si]
inc si
cmp al,cl
jge .noxchg
cbw
mov cx,ax ; looking for smaller one
.noxchg:
jcxz .empty
mov al,20h
mov ah,bh
xor bh,bh
mov dx,cx ; save final CX for later
push di
rep movsb ; copy eVerything
pop di
;+----
mov cx,bx
.werk:
push cx
mov cx,dx
repe scasb ; while space
dec di
mov [es:bp],di ; set offset
inc cx
add bp,byte 2
repne scasb ; while NOT space
jcxz .out
mov [es:di - 1],ah
mov dx,cx
pop cx
loop .werk
;+----
.out: mov [es:di],ah
pop cx
dec cx
sub cx,bx
neg cx
ret
.empty:
xor cx,cx
retn
[section .bss]
argc resw 1
argv resw 15
arg_buffer resb 64
parser_table resb 256
--
beppu AT uci DOT edu .............................................................
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