Assembly Simple OS coded in NASM (16-bit, both for QEMU or VBox) - Printable Version

[Assembly] Simple OS coded in NASM (16-bit, both for QEMU or VBox) - Printable Version

+- Hack Forums (https://hackforums.net)
+-- Forum: Tech (https://hackforums.net/forumdisplay.php?fid=444)
+--- Forum: Coding (https://hackforums.net/forumdisplay.php?fid=151)
+---- Forum: Coders Lounge (https://hackforums.net/forumdisplay.php?fid=5)
+---- Thread: [Assembly] Simple OS coded in NASM (16-bit, both for QEMU or VBox) (/showthread.php?tid=5500536)

Simple OS coded in NASM (16-bit, both for QEMU or VBox) - Infamia - Dec 21, 2016

OS (Click to View)

Code 
BITS 16

start:

    mov ax, 07C0h ; SET UP STACK

    mov ss, ax

    mov sp, 4096

    sub ax, 512

    mov ds, ax

main:

    xor ah, ah ; MAKE REGISTER AH 0

    int 16h ; GET KEYBOARD INPUT (one key)

    cmp ah, 50h ; BIOS SCANCODE FOR DOWN ARROW

    je down ; GO TO LABEL DOWN

    cmp ah, 48h ; COMPARE BIOS SCANCODE OF KEY TO THAT OF UP ARROW

    je up ; JUMP TO UP LABEL LATER IN CODE

    cmp ah, 4Bh ; AND SO ON

    je left

    cmp ah, 4Dh

    je right

    mov ah, 0Eh ; AFTER USERINPUT IS CALLED, ASCII CODE IS PLACED IN AL

    int 10h ; CALL INTERRUPT AND PRINT ASCII CODE FROM KEYBOARD

    cmp al, 10 ; www .asciitable. com

    je newline

    cmp al, 13 

    je newline

    cmp al, 8

    je backspace

    cmp al, 27

    je shutdown

    cmp al, 96

    je sshutdown

    jmp main

newline:

    mov al, 13 ; MAKE A CR/LF

    int 10h

    mov al, 10

    int 10h

    jmp main

down:

    mov ah, 0Fh ; MOVE POINTER DOWN

    int 10h

    mov ah, 03h

    int 10h

    inc dh

    mov ah, 2

    int 10h

    jmp main

up:

    mov ah, 0Fh ; MOVE POINTER UP

    int 10h

    mov ah, 03h

    int 10h

    dec dh

    mov ah, 2

    int 10h

    jmp main

left:

    mov ah, 0Fh ; MOVE LEFT

    int 10h

    mov ah, 03h

    int 10h

    dec dl ; I COULD'VE JUST DONE A BACKSPACE BUT IT WOULD HAVE DELETED USER TEXT

    mov ah, 2

    int 10h

    jmp main

right:

    mov ah, 0Fh ; MOVE POINTER RIGHT

    int 10h

    mov ah, 03h

    int 10h

    inc dl

    mov ah, 2

    int 10h

    jmp main

backspace:

    mov al, 0 ; MOVE A NULL WHICH DELETES CURRENT CHARACTER

    int 10h

    mov al, 8 ; THEN MAKE A SPACE SINCE NOW THE CHARACTER BEFORE IT IS SELECTED

    int 10h 

    jmp main ; GO  BACK TO MAIN

shutdown:

    int 20h ; full shutdown

sshutdown:

    int 19h ; restart

times 510-($-$$) db 0

dw 0AA55h ; BOOTLOADER SIGNATURE AT END OF SECTOR

times 1474560-($-$$) db 0 ; FILL FILE WITH 1440KB OF DATA  SO IT CAN BECOME A VALID FLOPPY

Build File (PYTHON) (Click to View)

BAT Exec (Click to View)

It isn't much, but it could be used for learning- it's written in pure NASM with-out any macros or C functions, so this can be just run under DOSBox with certain commands to build it to be so. But this does require prerequisites for it to work, one- being Python- is optional, and the other- NASM- isn't so optional unless you've found a way of building it manually.

Save the Assembly file as something like _os.asm (so it is at the top of the directory listing- usually) and the Python file under _build.py or something of the likes. If you cannot afford to download Python, then simply save the .bat as something like _build.bat and run it. (I don't know the equivalent for Linux, but it should be the same as calling NASM and just selecting the file)

This is a floppy file, so if you run it in Virtual Box or so; if any additions of code plus over 1440KB, you will encounter an error; thus you'll need to run it in QEMU as as far as I know, Virtual Box doesn't support plain binary formats. So just simply add an instruction in the Python file which calls qemu-system-i386 -fda _os.bin/flp (thus you'll need to have qemu installed, which isn't that big of a file.

My Github is at: https :// github .com/unazed/OS1 if you want to see older versions (or however Github works) or commit code. Thanks for reading.

Here's a picture of it being run in QEMU

imgur .com/GKdJcoK.png

* - Malicious Intent - Dec 21, 2016

Well done man. I hope you will develop this project into something bigger over the time. Good luck

* - Infamia - Dec 21, 2016

(Dec 21, 2016 02:50 PM)michypc Wrote: Well done man. I hope you will develop this project into something bigger over the time. Good luck

Thanks, I've commented the code since somebody on Discord suggested that people trying to read it might be baffled. I do plan on adding integration with languages like D or C later on, but I think I should make it a shell first. But nonetheless thanks for your post, my friend said people here would embarrass me or something ;)

* - Malicious Intent - Dec 21, 2016

(Dec 21, 2016 02:54 PM)Infamia Wrote: Thanks, I've commented the code since somebody on Discord suggested that people trying to read it might be baffled. I do plan on adding integration with languages like D or C later on, but I think I should make it a shell first. But nonetheless thanks for your post, my friend said people here would embarrass me or something ;)

Lol don't listen to your friend haha.. Yeah shell would be nice for sure. Its nice to see projects with big potential just taking of. As i said i hope you will continue to develop this. Bright future ahead buddy.

* - Infamia - Dec 21, 2016

(Dec 21, 2016 03:04 PM)michypc Wrote: Lol don't listen to your friend haha.. Yeah shell would be nice for sure. Its nice to see projects with big potential just taking of. As i said i hope you will continue to develop this. Bright future ahead buddy.

Oh God, I've just fallen into the problem of running out of space in the sector; I've written the shell already but I can't fit the most vital 2 bytes into there which signifies that it's actually bootable and an OS, I guess I'll have to write a bootloader first.

* - Malicious Intent - Dec 21, 2016

(Dec 21, 2016 04:59 PM)Infamia Wrote: Oh God, I've just fallen into the problem of running out of space in the sector; I've written the shell already but I can't fit the most vital 2 bytes into there which signifies that it's actually bootable and an OS, I guess I'll have to write a bootloader first.

Lol .. there you go... you will probably run into many problems like this but by the time you done with them you will have nice lil functional OS..

* - Infamia - Dec 21, 2016

(Dec 21, 2016 05:10 PM)michypc Wrote: Lol .. there you go... you will probably run into many problems like this but by the time you done with them you will have nice lil functional OS..

True man, I hope the rest of Hackforums is mostly like you, thusfar I've posted a few times in Lounge and I think the people are kind of nice but prone to getting mad at something annoying. I will try to keep the OS in on or two files however since I hate switching back and forth files, with the exception of build files of course.

* - Malicious Intent - Dec 21, 2016

Well ill be following this development..

* - Venom0 - Feb 15, 2017

Hey, nice work. I also have some experience with this. Have you planned on adding support for protected mode and memory segmentation? It would allow you to put in your shell. I could help you with that.

* - Infamia - Feb 16, 2017

(Feb 15, 2017 03:10 PM)Venom0 Wrote: Hey, nice work. I also have some experience with this. Have you planned on adding support for protected mode and memory segmentation? It would allow you to put in your shell. I could help you with that.

this idea is quite gone, sorry.

i'm learning more c/++ so i can cross-compile it later with the assembly and make an actual OS rather than a text editor with protected mode and all the other neat shit.

* - _L0cky_ - May 30, 2017

(Feb 16, 2017 12:29 AM)Infamia Wrote: this idea is quite gone, sorry.

i'm learning more c/++ so i can cross-compile it later with the assembly and make an actual OS rather than a text editor with protected mode and all the other neat shit.

Such a great post, it's a pity you're no longer into this.