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 Understanding Assembly 
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Joined: Tue Nov 17, 2009 11:10 am
Posts: 4
Post Understanding Assembly
I'm trying to understand the assembly in the boot.s example at this site:

http://jamesmolloy.co.uk/tutorial_html/2.-Genesis.html

The biggest part I'm having trouble with understanding is the multiboot headers. I figure that understanding the exact purpose of each will give an advantage to anyone, especially if you can somehow modify them to what you want.

Then my second question is:
IS THERE ANYWAY TO MAKE YOUR OWN VERSION OF THE "GRUB."

I don't like relying on Linux source code because it's so easy to say, "I'll just use this code" and pretty soon you have Linux, not something you can call your own. My mission is originality, NOT mimicking. My brain child (my OS) will not be a copy of someone else's brain child.

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Tue Nov 17, 2009 11:30 am
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Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: Understanding Assembly
hehe, I got yo'back man... its a relatively small easy specification so I decided to experiement while helping you out...

what I did was what I called an audio run-down... basically if you are like me and hate reading... and/or prefer somebody to vocally explain things to you I think this might help...

here is sections 1 and 2...
http://www.dudeofx.net/perma/misc/MultiBoot%20Spec%20sections%201%20and%202.mp3

today I also took notes on the some of section 3, its a little longer... I did get thru the Header part which should help you... I'll post it on the next msg cause I still gots to mixit!!!

BTW: umm... be gentle on downloading... these mp3s are like 4MB and I am hosting using my home server...


Wed Nov 18, 2009 4:05 pm
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Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: Understanding Assembly
the wind was opposing me on this one...
first I was unable to find a music clip long enough for this one...
then audacity was acting funky and saved blank mp3s

so I guess I'll finish it later

anywho here is a music-less version for now...

this only covers section 3.1
http://www.dudeofx.net/perma/misc/MultiBoot%20Spec%20section%203%20subsection%201.mp3


Wed Nov 18, 2009 6:22 pm
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Joined: Fri Nov 13, 2009 5:18 pm
Posts: 4
Post Re: Understanding Assembly
Hi for the first time i thaught that you are Dj-Asm (that's funny name )
Understanding the assembly will not be so easy.I really encourage people to make video tutorial that's better than books for me.For people who want to be expert in assembley i recommend that they read The Intel documentation because you will not miss any thing.I will prepare a video tutorial for you soon .Good Luck


Fri Nov 20, 2009 3:40 pm
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Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: Understanding Assembly
hehe I like that... DJ-Asm :lol:

but I already have an emblem so its CJ-DudeOfX ;)
get it CJ as in Code Jokey :lol:
Image

adding techno as background music RULEZ!!!!!
alas audio rundowns is actually hard work!


Mon Nov 23, 2009 10:07 am
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Joined: Sat Jul 25, 2009 7:44 am
Posts: 274
Location: United Kingdom
Post Re: Understanding Assembly
Cool lol, Code Jokey sound good :lol:

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Kieran C G Foot


Mon Nov 23, 2009 11:56 am
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Joined: Sat Jan 16, 2010 7:53 pm
Posts: 18
Location: Melbourne, Australia
Post Re: Understanding Assembly
BeserkerNomNom wrote:
IS THERE ANYWAY TO MAKE YOUR OWN VERSION OF THE "GRUB."

I don't like relying on Linux source code because it's so easy to say, "I'll just use this code" and pretty soon you have Linux, not something you can call your own. My mission is originality, NOT mimicking. My brain child (my OS) will not be a copy of someone else's brain child.


Your desire to not be copying someone else is understandable, of course, but don't get the situation wrong - GRUB isn't Linux and Linux ain't GRUB, and they're only vaguely connected (both GPL?). A bootloader is probably one of the least important parts of operating system development - 'real' companies don't write boot loaders any more, because there's simply no need - once they get your kernel image in memory and running, you can do whatever you want.

It's a much better idea to just use GRUB to get your image in memory and protected mode up - after that, you're free to move your kernel about in memory as you wish, and once you set up virtual memory, you'll mostly forget about where your kernel came from and how it came to exist in memory. Writing yet *another* bootloader doesn't help anyone - it means you're wasting time doing things everyone else has done before, except you can't do anything interesting or new in a bootloader - the goal is the same. Load some code from disk into memory.

But when you get to writing your kernel and system, *that's* when the fun starts. That's where your brain child starts, because that's when it's *your* creativity that chooses where to go.

Just a suggestion.


Sat Jan 16, 2010 8:19 pm
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Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: Understanding Assembly
and how many real companies write their own kernel? not many... well maybe for portable devices like cell phones and PMPs


Sat Jan 16, 2010 9:17 pm
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Joined: Sat Jan 16, 2010 7:53 pm
Posts: 18
Location: Melbourne, Australia
Post Re: Understanding Assembly
DudeOfX wrote:
and how many real companies write their own kernel? not many... well maybe for portable devices like cell phones and PMPs


Not many, of course. I was referring more to the major operating systems in existence today - Windows, various Unicies and what have you. The bootloader is about the most inconsequential part (is what I'm trying to say).

I think there are only a few companies who actually do write kernels for portable devices anyway - say, Symbian, Windows Mobile, PalmOS(? does that even exist still!?), Android recently, RIM Blackberry, and iPhone OS. The rest are just layers on top of those.


Sun Jan 17, 2010 3:05 am
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Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: Understanding Assembly
you forgot the 'Others' aka 'Generics' category like chinese media players and cell phones... they don't run main stream OSs but they run an OS non-tha-less... hence they write their own kernels...


Sun Jan 17, 2010 1:13 pm
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