Writing applications for KolibriOS
Structure of an application
Programming for KolibriOS is easy as you first learn the basic structure of an application. At this point I assume you have some experience in assembly language. The KolibriOS API (Application Programming Interface) is a easy-to-learn set of functions with practically no hierarchial accesses.
The operating of an application is based on events. The application is notified by the OS with the event type and the application acts accordingly. There are three event types an application is expected to handle by default: window redraw, keypress and buttonpress.
Flow chart and structure of an application with default events:
<syntaxhighlight>
- ;
- HEADER DATA ;
- ;
START:
call draw_window
- ;
- WAIT UNTIL EVENT ; <-----------------------------------------------I
- ; I
- I
- I
- I
- ; redraw -> call draw_window -> I
- READ EVENT TYPE ; -> key -> read keypress -> process -> I
- ; button -> read buttonpress -> process -> I
draw_window:
- ;
- DRAW STATIC WINDOW PARTS ;
- ;
ret
- ;
- STATIC DATA ;
- ;
</syntaxhighlight>
The header
<syntaxhighlight> db 'MENUET01' </syntaxhighlight>
Since KolibriOS still is more or less API compatible with MenuetOS, it has the same header. There is also an older version of the header wich uses 'MENUET00' but it should not be used anymore.
<syntaxhighlight> dd 0x01 ; header version </syntaxhighlight>
Speaks for itself.
<syntaxhighlight> dd START ; start of execution </syntaxhighlight>
START is the label in your program where kernel will jump to after loading the program. You could use another name, but it's convenient to always use the same.
<syntaxhighlight> dd I_END ; size of image </syntaxhighlight>
This is the total size of the program code in bytes, its easy to use a label wich you place at the end of the code.
<syntaxhighlight> dd 0x100000 </syntaxhighlight>
This is the amount of ram that will be reserved for your app. You could use a static value as shown here, or you could use I_END + xx bytes. There, I_END would be the label to the end of code + all static declarations you made after the code. The xx bytes then are the number of bytes you want to use for the stack. Also note, this value can later be changed by using system functions.
<syntaxhighlight> dd 0x100000 ; stack position in memory area </syntaxhighlight>
Where the end of stack is (the value of esp at start of program). Logically, this would be the same as the previous value.
<syntaxhighlight> dd 0x0 ; Parameters </syntaxhighlight>
If you want to use parameters, this should be a pointer to a 1024 byte buffer, in wich those parameters will be written by the kernel. If you dont want to use them, set this dword to 0.
<syntaxhighlight> dd 0x0 ; Path </syntaxhighlight>
Path value, works the same as parameter.
System calls
The System calls (API) are explained in various sources. There is the file syscalls.txt wich you can find in kolibrios itself, but also in the zip file of the distribution.< If you understand russian, you can also find system calls on this wiki.
To execute a system call, you first need to fill the registers with the correct value. Say we want to wait a couple of milliseconds, we need to use system function 5 and place the time we want to wait in ebx.
<syntaxhighlight>
mov eax, 5 mov ebx, 10
</syntaxhighlight>
Now, we need to execute the function, this can be done with int 0x40:
<syntaxhighlight>
int 0x40
</syntaxhighlight>
But also with more modern instructions such as syscall, sysenter etc. It's convenient to use the mcall macro from macros.inc, then you can chose to use int 0x40 or another method, at compile time. This macro also accepts parameters, first is eax, second is ebx, ... Code for the above would be:
<syntaxhighlight>
mcall 5, 10
</syntaxhighlight>
Coding Style
It's adviseable to use the coding style, as descibed here: Style
The API
You can find the latest API documention in /kernel/docs/ in the SVN repository (WebSVN)
Assembly examples
Simple example
<syntaxhighlight>
- ;
- EXAMPLE APPLICATION ;
- ;
- Compile with FASM ;
- ;
- The header
use32 ; Tell compiler to use 32 bit instructions
org 0x0 ; the base address of code, always 0x0
db 'MENUET01' dd 0x01 dd START dd I_END dd 0x100000 dd 0x7fff0 dd 0, 0
- The code area
include 'macros.inc'
START: ; start of execution
call draw_window ; draw the window
- After the window is drawn, it's practical to have the main loop.
- Events are distributed from here.
event_wait:
mov eax, 10 ; function 10 : wait until event mcall ; event type is returned in eax
cmp eax, 1 ; Event redraw request ? je red ; Expl.: there has been activity on screen and ; parts of the applications has to be redrawn.
cmp eax, 2 ; Event key in buffer ? je key ; Expl.: User has pressed a key while the ; app is at the top of the window stack.
cmp eax, 3 ; Event button in buffer ? je button ; Expl.: User has pressed one of the ; applications buttons.
jmp event_wait
- The next section reads the event and processes data.
red: ; Redraw event handler
call draw_window ; We call the window_draw function and jmp event_wait ; jump back to event_wait
key: ; Keypress event handler
mov eax, 2 ; The key is returned in ah. The key must be mcall ; read and cleared from the system queue. jmp event_wait ; Just read the key, ignore it and jump to event_wait.
button: ; Buttonpress event handler
mov eax,17 ; The button number defined in window_draw mcall ; is returned to ah. cmp ah,1 ; button id=1 ? jne noclose mov eax,-1 ; Function -1 : close this program mcall
noclose:
jmp event_wait ; This is for ignored events, useful at development
- *********************************************
- ****** WINDOW DEFINITIONS AND DRAW ********
- *********************************************
- The static window parts are drawn in this function. The window canvas can
- be accessed later from any parts of this code (thread) for displaying
- processes or recorded data, for example.
- The static parts *must* be placed within the fn 12 , ebx = 1 and ebx = 2.
draw_window:
mov eax, 12 ; function 12: tell os about windowdraw mov ebx, 1 ; 1, start of draw mcall
mov eax, 0 ; function 0 : define and draw window mov ebx, 100 * 65536 + 300 ; [x start] *65536 + [x size] mov ecx, 100 * 65536 + 120 ; [y start] *65536 + [y size] mov edx, 0x14ffffff ; color of work area RRGGBB ; 0x02000000 = window type 4 (fixed size, skinned window) mov esi, 0x808899ff ; color of grab bar RRGGBB ; 0x80000000 = color glide mov edi, title mcall
mov ebx, 25 * 65536 + 35 ; draw info text with function 4 mov ecx, 0x224466 mov edx, text mov esi, 40 mov eax, 4
.newline: ; text from the DATA AREA mcall add ebx, 10 add edx, 40 cmp byte[edx], 0 jne .newline
mov eax, 12 ; function 12:tell os about windowdraw mov ebx, 2 ; 2, end of draw mcall
ret
- *********************************************
- ************* DATA AREA *****************
- *********************************************
- Data can be freely mixed with code to any parts of the image.
- Only the header information is required at the beginning of the image.
text db "It look's like you have just compiled "
db "your first program for KolibriOS. " db " " db "Congratulations! ", 0
title db "Example application", 0
I_END:
- The area after I_END is free for use as the application memory,
- just avoid the stack.
- Application memory structure, according to the used header, 1 Mb.
- 0x00000 - Start of compiled image
- I_END - End of compiled image
- + Free for use in the application
- 0x7ff00 - Start of stack area
- 0x7fff0 - End of stack area - defined in the header
- + Free for use in the application
- 0xFFFFF - End of freely useable memory - defined in the header
- All of the the areas can be modified within the application with a
- direct reference.
- For example, mov [0x80000],byte 1 moves a byte above the stack area.
</syntaxhighlight>
It should look like this (perhaps with other skin):
KolibriOS's application structure is not specifically reserved for asm programming, the header can be produced with practically any other language. However, the overall application programming design is intended for easy 32 bit asm programming. The GUI is extremely easy to handle with especially asm language.
Using uniform system colours
While previous example concentrated on creating a basic application, in this section more attention is paid on the outlook of the window.
You can use uniform desktop colors defined by a colour setup application.
New fuction in this example is get_system_colours.
<syntaxhighlight>
- ;
- UNIFORM SYSTEM COLOURS EXAMPLE ;
- ;
- Compile with FASM ;
- ;
- The header
use32
org 0x0
db 'MENUET01' dd 1, START, I_END, 0x100000, 0x7fff0, 0, 0
- The code area
window_size_X equ 300 window_size_Y equ 150
include 'macros.inc'
START: ; start of execution
call draw_window ; draw the window
- After the window is drawn, it's practical to have the main loop.
- Events are distributed from here.
event_wait:
mcall 10 ; function 10 : wait until event ; event type is returned in eax
- How the 'dec' instruction in the following code works
- example
- If a window redraw is needed, eax will be 1
- So if we decrement eax, eax will become 0
- 'dec' instruction will set Zero-Flag because eax is now zero
- So now we can use jz (jump if zero flag is set) to detect this..
- If eax is 2, it will take 2 time 'dec eax' before zero flag will be set..
dec eax ; Event redraw request ? jz red ; Expl.: there has been activity on screen and ; parts of the applications has to be redrawn.
dec eax ; Event key in buffer ? jz key ; Expl.: User has pressed a key while the ; app is at the top of the window stack.
dec eax ; Event button in buffer ? jz button ; Expl.: User has pressed one of the ; applications buttons.
jmp event_wait
- The next section reads the event and processes data.
red: ; Redraw event handler
call draw_window ; We call the window_draw function and jmp event_wait ; jump back to event_wait
key: ; Keypress event handler
mcall 2 ; The key is returned in ah. The key must be read and cleared from the system queue. jmp event_wait ; Just read the key, ignore it and jump to event_wait.
button: ; Buttonpress event handler
mcall 17 ; The button number defined in window_draw is returned to ah.
cmp ah, 1 ; button id=1 ? jne event_wait ; if not, go back and wait for other events
mcall -1 ; Function -1 : close this program
get_system_colours:
pusha
mov eax, 48 ; fn 48 system colours mov ebx, 3 ; subfn 3 : get mov ecx, app_colours ; pointer to return area mov edx, 10 * 4 ; number of bytes to return mcall
popa
ret
- WINDOW DEFINITIONS AND DRAW ********
- The static window parts are drawn in this function. The window canvas can
- be accessed later from any parts of this code (thread) for displaying
- processed or recorded data, for example.
- The static parts *must* be placed within the fn 12 , ebx = 1 and ebx = 2.
- When using system colours, the window colours are read from the
- SYSTEM COLOURS TABLE
draw_window:
mcall 12, 1 ; Tell OS about start of redraw
call get_system_colours ; fetches system colours from os
mov eax, 0 ; function 0 : define and draw window
mov ebx, 100 * 65536 + window_size_X ; [x start] *65536 + [x size] mov ecx, 100 * 65536 + window_size_Y ; [y start] *65536 + [y size]
mov edx, [w_work] ; color of work area 0xRRGGBB or edx, 0x14000000 ; 0x14000000 = window type 4, with title mov esi, [w_grab] ; color of grab bar 0xRRGGBB or esi, 0x80000000 ; 0x80000000 = colour glide mov edi, title mcall
mov ebx, 25 * 65536 + 35 ; draw info text with function 4 mov ecx, [w_work_text] mov edx, text ; text from the DATA AREA mov esi, 40
mov eax, 4
.newline: mcall add ebx, 10 add edx, 40 cmp byte [edx], 0 jne .newline
mcall 12, 2 ; end of redraw
ret
- *********************************************
- ************* DATA AREA *****************
- *********************************************
- Data can be freely mixed with code to any parts of the image.
- Only the header information is required at the beginning of the image.
text db 'THIS PROGRAM USES UNIFORM SYSTEM COLOURS'
db 'RETURNED TO A TABLE ', 0
title db 'EXAMPLE APPLICATION', 0
I_END:
app_colours: ; SYSTEM COLOURS TABLE
w_frames dd ? ; - frames w_grab dd ? ; - GRAB AREA w_grab_button dd ? ; grab area button w_grab_button_text dd ? ; grab area button text w_grab_text dd ? ; grab area text w_work dd ? ; - WORK AREA w_work_button dd ? ; work area button w_work_button_text dd ? ; work area button text w_work_text dd ? ; work area text w_work_graph dd ? ; work area graphics
</syntaxhighlight>
Freeform window
In this example we concentrate on shaping the window from rectangle to any form desired by the programmer. New fuction in this example is shape_window.
<syntaxhighlight>
- ;
- FREEFORM EXAMPLE APPLICATION ;
- ;
- Compile with FASM ;
- ;
- The header
use32
org 0x0
db 'MENUET01' dd 1, START, I_END, 0x100000, 0x7fff0, 0x0, 0x0
include 'macros.inc'
START: ; start of execution
call shape_window ; function for shaping call draw_window ; at first, draw the window
still:
mcall 10 ; wait here for event
dec eax ; redraw request ? jz red
dec eax ; key in buffer ? je key
dec eax ; button in buffer ? je button
jmp still
red: ; redraw
call draw_window jmp still
key: ; key
mcall 2 ; just read it and ignore jmp still
button: ; button
mcall 17 ; get id cmp ah, 1 ; button id=1 ? jne noclose
mcall -1 ; close this program
noclose:
jmp still
shape_window:
pusha
- give the shape reference area
mcall 50, 0, shape_reference
- give the shape scale 32 x 32 -> 128 x 128
- you dont have to give this, scale is 1
- 1 by default
- scale is set to 2^ecx
mcall 50, 1, 2
popa ret
shape_reference: ; 32 x 32, ( window_size_X + 1 ) * ( window_size_Y + 1 )
db 0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0 db 0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0 db 0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0 db 0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0 db 0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0 db 0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0 db 0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0 db 0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0 db 0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0 db 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0 db 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0 db 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0 db 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0 db 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0 db 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0 db 0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0 db 0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0 db 0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0 db 0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0 db 0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0 db 0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0 db 0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0 db 0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0 db 0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0 db 0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0
- WINDOW DEFINITIONS AND DRAW ********
draw_window:
mcall 12, 1 ; notice os about start of redraw
mov eax, 0 ; function 0: define and draw window mov ebx, 100 * 65536 ; [x start] * 65536 + [x size] mov ecx, 100 * 65536 ; [y start] * 65536 + [y size] mov bx , [x_size] mov cx , [y_size] mov edx, 0x00cccc00 ; color of work area RRGGBB,8->color glide mov esi, 0x00cccc00 ; color of grab bar RRGGBB,8->color glide mov edi, 0x00cccc00 ; color of frames RRGGBB mcall
mov eax, 8 ; function 8: define and draw button mov ebx, 78 * 65536 + 12 ; [x start] * 65536 + [x size] mov ecx, 20 * 65536 + 12 ; [y start] * 65536 + [y size] mov edx, 1 ; button id mov esi, 0x5599cc ; button color RRGGBB mcall
mcall 12, 2 ; end of redraw
ret
- DATA
x_size dw 127 y_size dw 127
I_END: </syntaxhighlight>
Threads
KolibriOS assembly threading has some great advantages over higher level languages. If you keep all the variables in registers, you can start as meny threads as desired with the _same_ code, since no memory is affected and needs no saving. The registers are saved to Task Switch Segments by KolibriOS. All you have to do is to set a new stack.
Threads have no difference with the main process and use the same memory area as the process which starts it. They can have their own independent windows etc. In the closing of application, all threads have to be terminated with the default (eax = -1) system call.
New function in this example is create_thread.
<syntaxhighlight>
- ;
- THREAD EXAMPLE ;
- ;
- Compile with FASM for Menuet ;
- ;
use32
org 0x0
db 'MENUET01' ; 8 byte id for application dd 1, START, I_END, 0x100000, 0x80000, 0x0, 0x0
include 'macros.inc'
START: ; start of execution
call draw_window ; at first, draw the window
event_wait:
mov eax, 10 ; wait here for event mcall
cmp eax, 1 ; redraw request ? je red cmp eax, 2 ; key in buffer ? je key cmp eax, 3 ; button in buffer ? je button
jmp event_wait
red: ; redraw
call draw_window jmp event_wait
key: ; key
mov eax, 2 ; just read it and ignore mcall jmp event_wait
button: ; button
mov eax, 17 ; get id mcall
cmp ah, 1 ; button id=1 ? jne noclose mov eax, -1 ; close this program (thread) mcall
noclose:
cmp ah, 2 ; call create_thread jne no_thread call create_thread jmp event_wait
no_thread:
jmp event_wait
- THREAD CREATION
- All we have to do is to give the thread entry address in ecx and
- a new stack postition in edx with function eax=51, ebx=1
create_thread:
cmp [thread_stack], 0xf0000 jge no_new_thread add [thread_stack], 0x1000 mov eax, 51 ; thread_create system call mov ebx, 1 mov ecx, START mov edx, [thread_stack] mcall
no_new_thread:
ret
thread_stack dd 0x80000
- WINDOW DEFINITIONS AND DRAW ********
draw_window:
mov eax, 12 ; function 12: tell os about windowdraw mov ebx, 1 ; 1, start of draw mcall
mov eax, 0 ; function 0: define and draw window mov ebx, 10 * 65536 + 300 ; [x start] * 65536 + [x size] mov ecx, 10 * 65536 + 140 ; [y start] * 65536 + [y size] mov esi, [thread_stack] sub esi, 0x80000 shr esi, 11 shl esi, 16 add ebx, esi add ecx, esi mov edx, 0x02ffffff ; color of work area RRGGBB,8->color glide mov esi, 0x808899ff ; color of grab bar RRGGBB,8->color glide mov edi, 0x008899ff ; color of frames RRGGBB mcall
; WINDOW LABEL mov eax, 4 ; function 4: write text to window mov ebx, 8 * 65536 + 8 ; [x start] * 65536 + [y start] mov ecx, 0x00ddeeff ; color of text RRGGBB mov edx, labelt ; pointer to text beginning mov esi, labellen-labelt ; text length mcall
; CLOSE BUTTON mov eax, 8 ; function 8: define and draw button mov ebx, (300 - 19) * 65536 + 12 ; [x start] * 65536 + [x size] mov ecx, 5 * 65536 + 12 ; [y start] * 65536 + [y size] mov edx, 1 ; button id mov esi, 0x6677cc ; button color RRGGBB mcall
; NEW THREAD BUTTON mov eax, 8 mov ebx, 25 * 65536 + 128 mov ecx, 88 * 65536 + 20 mov edx, 2 mov esi, 0x6677cc mcall
mov ebx, 25 * 65536 + 35 ; draw info text with function 4 mov ecx, 0x224466 mov edx, text mov esi, 40
.newline: mov eax, 4 mcall add ebx, 10 add edx, 40 cmp byte[edx], 0 jne .newline
mov eax, 12 ; function 12: tell os about windowdraw mov ebx, 2 ; 2, end of draw mcall
ret
- DATA AREA
text:
db 'THIS EXAMPLE CREATES THREADS BY RUNNING ' db 'THE SAME CODE MULTIPLE TIMES. ALL WE ' db 'NEED IS A NEW STACK FOR EACH THREAD. ' db 'ALL THREADS SHARE THE SAME MEMORY. ' db ' ' db ' ' db ' CREATE NEW THREAD ', 0
labelt:
db 'THREAD EXAMPLE'
labellen:
I_END: </syntaxhighlight>
Real-Time data
The following example focuses on Real-Time data fetching and processing. Application informs the OS for all the ports and datatypes to read at a specific IRQ.
Steps:
- reserve I/O port area
- reserve IRQ
- program IRQ
- program EVENT list for wanted IRQ
- runtime processing of the data
- back to default events - free IRQ from EVENT list
- free IRQ
- free port area
- terminate program
After IRQ's are programmed, the application has a new event for the main event loop, number (IRQ+16). When the application receives this event, the OS has recorded data ready for the application to process.
The table below shows the main structure of processing real time data. All the steps on the left of (A) are processed by the OS and the steps right from (A) are processed by the application.
IRQ OWNER => REC DATA (A) SYS_EVENT => READ DATA => PROCESS 0 TIMER SYS 1 KEYBOARD SYS 2 free -> 3 COM MOUSE SYS/free ?> 4 COM MOUSE SYS/free ?> 5 SOUND BL. SYS 6 FLOPPY SYS 7 free -> 8 free -> 9 free -> 10 free -> 11 free -> 12 PS2 MOUSE SYS/free ?> 13 MATH PR. SYS 14 IDE SYS 15 IDE SYS
An example of processing Real-Time data:
<syntaxhighlight>
- ;
- REAL-TIME DATA ;
- ;
- Compile with FASM for Menuet ;
- ;
use32
org 0x0
db 'MENUET01' ; 8 byte id for application dd 1, START, I_END, 0x100000, 0x7fff0, 0x0, 0x0
include 'macros.inc'
START: ; start of execution
call draw_window ; at first, draw the window call program_real_time_data ; program the OS to receive real time data call program_com_port ; program the com port for specific device
event_wait:
mov eax, 10 ; wait here for event mcall
cmp eax, 1 ; redraw request ? je red cmp eax, 2 ; key in buffer ? je key cmp eax, 3 ; button in buffer ? je button
cmp eax, 16 + 4 ; RT: new event for wanted IRQ data (16+IRQ) je read_rt
jmp event_wait
- The next section reads the event and processes data.
read_rt: ; RT data
mov eax, 42 ; Function 42 returns recorded data for IRQ 4 mov ebx, 4 ; mcall ; OS returns the recorded data. ; eax number of bytes in buffer left ; bl data ; ecx 0 = success, other = no data in buf.
call process_data jmp event_wait
red: ; redraw
call draw_window jmp event_wait
key: ; key
mov eax, 2 ; just read it and ignore mcall jmp event_wait
button: ; button
mov eax, 17 ; get id mcall
cmp ah, 1 ; button id=1 ? jne noclose call free_real_time_data mov eax, -1 ; close this program mcall
noclose:
jmp event_wait
program_real_time_data:
; Program the Real-Time data fetch ; ; 1) reserve I/O port area ; 2) reserve IRQ ; 3) program IRQ ; 4) program EVENT list for wanted IRQ
pusha
mov eax, 46 ; reserve ports 0x3f0 - 0x3ff mov ebx, 0 mov ecx, 0x3f0 mov edx, 0x3ff mcall
mov eax, 45 ; reserve irq 4 mov ebx, 0 mov ecx, 4 mcall
mov eax, 44 ; set read ports for irq 4 mov ebx, irqtable mov ecx, 4 mcall
mov eax, 40 ; get com 1 data with irq 4 mov ebx, 0000000000010000b shl 16 + 111b ; after this we have a new event (16+4) mcall
popa ret
irqtable:
dd 0x3f8+0x01000000 ; 3f8 =port to read : 01 =read byte, 02 =read word
dd 0x0 ; 0x0 = termintes read per IRQ event dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0 dd 0x0
free_real_time_data:
; Free the used resources ; ; 1) get default events ; 2) free irq with function 45,1 ; 3) free port area with function 46,1
pusha
mov eax, 40 ; default events - disable irq 4 event mov ebx, 111b mcall
mov eax, 45 ; free irq mov ebx, 1 mov ecx, 4 mcall
mov eax, 46 ; free ports 0x3f0-0x3ff mov ebx, 1 mov ecx, 0x3f0 mov edx, 0x3ff mcall
popa ret
- The following functions are for processing device specific data.
process_data:
cmp ebx, 80 jne .nocd
mov eax, 19 mov ebx, cdplayer mov ecx, 0 mcall
.nocd: push ebx mov eax, [pos] add eax, 1 cmp eax, 10 * 20 + 1 jb .noeaxz mov esi, text + 10 * 4 mov edi, text mov ecx, 10 * 21 * 4 cld rep movsb mov eax, 13 mov ebx, 20 * 65536 + 260 mov ecx, 22 * 65536 + 220 mov edx, [wcolor] mcall mov eax,10*19+1
.noeaxz: mov [pos],eax pop ebx and ebx,0xff
call draw_data
ret
draw_data: