21
Programming with NASM / Re: IDE for asm
« Last post by avcaballero on October 06, 2019, 07:25:54 AM »Notepad++ (+) batch file?
Recent Posts
22
Using NASM / which ide for asm
« Last post by trazom on October 05, 2019, 09:38:37 PM »hello,
which asm compiler and IDE unser Linux Centos7
which asm compiler and IDE unser Linux Centos7
23
Programming with NASM / IDE for asm
« Last post by trazom on October 05, 2019, 09:31:28 PM »Hello,
which program to use to edit and compile asm?
T
which program to use to edit and compile asm?
T
24
Using NASM / Re: How do I define a function alias for an imported function?
« Last post by vitsoft on October 05, 2019, 08:14:58 AM »The second method (the actual Windows DLL forwarding) is, IMHO, up to the linker, not the compiler/nasm.Indeed. In EuroAssembler linker is DLL forwarding implemented at export with keyword FWD=. Example of linker script:
Code: [Select]
proxy PROGRAM Format=DLL
EXPORT abcd1234, LIB=original.dll, FWD=abcd
ENDPROGRAMThose three lines, when euroassembled, will create proxy.dll which exports function abcd from original.dll under a new name abcd1234.
25
Programming with NASM / Re: Problems with interrupt 1Ah
« Last post by avcaballero on October 01, 2019, 01:23:50 PM »Look if this helps
26
Programming with NASM / Problems with interrupt 1Ah
« Last post by yoran on September 29, 2019, 09:04:47 AM »(16 bit NASM bare bones)
I use int 1Ah to get time and date, however the time functions seems to have stopped working for some reason.
My time function:
;I/O: BX = string location
get_time:
pusha
mov di, bx
clc ;anti bios-bug team
mov ah, 2 ;BIOS time > bcd
int 1Ah
jnc .read
clc
mov ah, 2
int 1Ah
.read:
mov al, ch ;hours > integer
call bcd_to_int
mov dx, ax ;save
mov al, ch ;hour
shr al, 4 ;higher bcd > lower
and ch, 0Fh ;1`s
test byte [fmt_12_24], 0FFh
jz .twelve_hr
call .add_digit
mov al, ch
call .add_digit
jmp short .minutes
.twelve_hr:
cmp dx, 0
je .midnight
cmp dx, 10
jl .twelve_st1
cmp dx, 12
jle .twelve_st2
mov ax, dx
sub ax, 12
mov bl, 10
div bl
mov ch, ah
cmp al, 0 ;1-9 PM
je .twelve_st1
jmp short .twelve_st2 ;10-11 PM
.midnight:
mov al, 1
mov ch, 2
.twelve_st2:
call .add_digit ;modified bcd
.twelve_st1:
mov al, ch
call .add_digit
mov al, ':'
stosb
.minutes:
mov al, cl ;minute
shr al, 4 ;higher bcd > lower
and cl, 0Fh ;1`s
call .add_digit
mov al, cl
call .add_digit
mov al, ' '
stosb
mov si, .hours_format ;assume 24 hour format
test byte [fmt_12_24], 0FFh
jnz .copy
mov si, .pm_format ;pm?
cmp dx, 12 ;test it!
jg .copy
mov si, .am_format ;no? am!
.copy:
lodsb
stosb
cmp al, 0
jne .copy
popa
ret
.add_digit:
add al, '0' ;into ASCII
stosb ;string into buffer
ret
.hours_format db 'hours',0
.am_format db 'AM',0
.pm_format db 'PM',0
However my date function still works so Im guessing it isnt to do with the interrupt itself:
;I/O: BX = string
get_date:
pusha
mov di, bx
clc ;anti-bug
mov ah, 4 ;data from BIOS in BCD
int 1Ah
jnc .fmt1_day
clc
mov ah, 4 ;BIOS updating
int 1Ah
.fmt1_day:
mov ah, dl ;dd
call .add_2digits
mov al, '/'
stosb ;d/m seperator
.fmt1_month:
mov ah, dh ;mm
call .add_2digits
mov al, '/'
stosb
.fmt1_century:
mov ah, ch ;??00
call .add_2digits
.fmt1_year:
mov ah, cl ;00??
call .add_2digits
mov al, 0
stosb
popa
ret
.add_2digits:
mov al, ah ;AH to 2 ASCII dig
shr al, 4
call .add_digit
mov al, ah
and al, 0Fh
call .add_digit
ret
.add_digit:
add al, '0'
stosb
ret
How do I fix the time function?
It will either: leak a bit of the memory and crash or just crash (crash as in stop, behaves like jmp $)
EDIT:
I have added a password function to my OS, after I implemented it the get_time function stopped working.
If I do not enter the password and fall back to my terminal, and then use the time function it DOES work, does this have to do with memory leaks/overflows?
EDIT 2: It also seems to depend on the length of the password, if its 1 char then it doesnt "influence" the time function but if its longer the function stops working.
EDIT 3: After debugging a bit the code seems to get stuck at the call bcd_to_int, it does not reach it nor does it return. The bcd_to_int function itself does work however
I use int 1Ah to get time and date, however the time functions seems to have stopped working for some reason.
My time function:
;I/O: BX = string location
get_time:
pusha
mov di, bx
clc ;anti bios-bug team
mov ah, 2 ;BIOS time > bcd
int 1Ah
jnc .read
clc
mov ah, 2
int 1Ah
.read:
mov al, ch ;hours > integer
call bcd_to_int
mov dx, ax ;save
mov al, ch ;hour
shr al, 4 ;higher bcd > lower
and ch, 0Fh ;1`s
test byte [fmt_12_24], 0FFh
jz .twelve_hr
call .add_digit
mov al, ch
call .add_digit
jmp short .minutes
.twelve_hr:
cmp dx, 0
je .midnight
cmp dx, 10
jl .twelve_st1
cmp dx, 12
jle .twelve_st2
mov ax, dx
sub ax, 12
mov bl, 10
div bl
mov ch, ah
cmp al, 0 ;1-9 PM
je .twelve_st1
jmp short .twelve_st2 ;10-11 PM
.midnight:
mov al, 1
mov ch, 2
.twelve_st2:
call .add_digit ;modified bcd
.twelve_st1:
mov al, ch
call .add_digit
mov al, ':'
stosb
.minutes:
mov al, cl ;minute
shr al, 4 ;higher bcd > lower
and cl, 0Fh ;1`s
call .add_digit
mov al, cl
call .add_digit
mov al, ' '
stosb
mov si, .hours_format ;assume 24 hour format
test byte [fmt_12_24], 0FFh
jnz .copy
mov si, .pm_format ;pm?
cmp dx, 12 ;test it!
jg .copy
mov si, .am_format ;no? am!
.copy:
lodsb
stosb
cmp al, 0
jne .copy
popa
ret
.add_digit:
add al, '0' ;into ASCII
stosb ;string into buffer
ret
.hours_format db 'hours',0
.am_format db 'AM',0
.pm_format db 'PM',0
However my date function still works so Im guessing it isnt to do with the interrupt itself:
;I/O: BX = string
get_date:
pusha
mov di, bx
clc ;anti-bug
mov ah, 4 ;data from BIOS in BCD
int 1Ah
jnc .fmt1_day
clc
mov ah, 4 ;BIOS updating
int 1Ah
.fmt1_day:
mov ah, dl ;dd
call .add_2digits
mov al, '/'
stosb ;d/m seperator
.fmt1_month:
mov ah, dh ;mm
call .add_2digits
mov al, '/'
stosb
.fmt1_century:
mov ah, ch ;??00
call .add_2digits
.fmt1_year:
mov ah, cl ;00??
call .add_2digits
mov al, 0
stosb
popa
ret
.add_2digits:
mov al, ah ;AH to 2 ASCII dig
shr al, 4
call .add_digit
mov al, ah
and al, 0Fh
call .add_digit
ret
.add_digit:
add al, '0'
stosb
ret
How do I fix the time function?
It will either: leak a bit of the memory and crash or just crash (crash as in stop, behaves like jmp $)
EDIT:
I have added a password function to my OS, after I implemented it the get_time function stopped working.
If I do not enter the password and fall back to my terminal, and then use the time function it DOES work, does this have to do with memory leaks/overflows?
EDIT 2: It also seems to depend on the length of the password, if its 1 char then it doesnt "influence" the time function but if its longer the function stops working.
EDIT 3: After debugging a bit the code seems to get stuck at the call bcd_to_int, it does not reach it nor does it return. The bcd_to_int function itself does work however
27
Summer of Code Ideas / Re: Can NASM get a debugger?
« Last post by Frank Kotler on September 25, 2019, 08:24:14 PM »Hi mayureshkathe,
Welcome to the forum.
I am only guessing, but I would guess that Nasm will not soon be seeing a "netwide" debugger. While Patrick's ALD is great for Linux and the BSDs, it won't do much for our dos/doze users who have not yet made the step up.
Unless you'd like to contribute something...
Best,
Frank
Welcome to the forum.
I am only guessing, but I would guess that Nasm will not soon be seeing a "netwide" debugger. While Patrick's ALD is great for Linux and the BSDs, it won't do much for our dos/doze users who have not yet made the step up.
Unless you'd like to contribute something...
Best,
Frank
28
Summer of Code Ideas / Can NASM get a debugger?
« Last post by mayureshkathe on September 25, 2019, 08:39:28 AM »Can the NASM distribution get a assembly language debugger too?
Searching around led me to http://ald.sourceforge.net/
Maybe the team can learn how ALD does it and build something of their own for NASM!
Searching around led me to http://ald.sourceforge.net/
Maybe the team can learn how ALD does it and build something of their own for NASM!
29
Programming with NASM / Re: how to split my 16bit/dos/medium model sample into files
« Last post by llm on September 18, 2019, 03:56:03 AM »Quote
My first thought is to declare "global seg000" alongside of "global text". Try that and see if it helps any...
global seg000 in seg000.asm does not help and i don't think that the segment is handled like an external at all
but i solved it by adding an segment "forward declaration" inc that contains all segments (empty and in order)
segments.inc
Code: [Select]
BITS 16
segment seg000
segment seg001
segment seg002
segment seg003 stack
and included that
seg001.asm
Code: [Select]
BITS 16
%include "segments.inc"
extern print
segment seg001
..start:
mov ax,seg000
mov ds,ax
call far print
mov ax,0x4c00
int 0x21
seems to work - but i still don't know if it is the "correct" way of doing it
30
Programming with NASM / Re: how to split my 16bit/dos/medium model sample into files
« Last post by Frank Kotler on September 17, 2019, 08:52:31 PM »Hi lim,
Welcome to the forum. Congratulations on your determination!
At one time, I knew how to do this... but that was a long time ago!
My first thought is to declare "global seg000" alongside of "global text". Try that and see if it helps any...
I wish I could help more but I'm old and tired and my memory is all shot. Examples I had were lost in a crash with no backup... Good luck!
Best,
Frank
Welcome to the forum. Congratulations on your determination!
At one time, I knew how to do this... but that was a long time ago!
My first thought is to declare "global seg000" alongside of "global text". Try that and see if it helps any...
I wish I could help more but I'm old and tired and my memory is all shot. Examples I had were lost in a crash with no backup... Good luck!
Best,
Frank