My first attempt to understand this Raspberry Pi

[Heater]

DexOS,

OK, I'm with you, "bare metal OS" can provide services but does not disalow direct hardware interaction. Fair enough.

50k and has all the normal stuff like cli, gui, tcp/ip stack, has a fasm port and ide

That is an impressive feat. Especially to now have it in two different architecture versions. Why did you go that way rather han using C or other HLL?

I'd certainly be interested in trying out your x86 version. I'm curious.

[DexOS]

At the beginning it was going to be a pascal OS, but it ended up 90% inline assembly, so i just switched to 100% ASM.
Theres a common belief that people only code in ASM to optimize code for speed or size, but there are some crazy people out there that actually like coding in assembly, we are control freaks and these very same control freaks are also the the type to code there own OS .

You can download and test the x86 ver here: http://www.dex-os.com/
You can run it in a emulator to test it.

You can also test some of the function of the arm ver here: http://www.dex-os.com/DexBasic/DexBasic.htm

Just follow the tuts, which uses fasms macro to make a basic like language.
The full OS with cli and gui will be released what i have done the pcb boards.
There's also youtube videos if you search for "ASM OS"

[Heater]

DexOS,

I can imagine writing an OS in Pascal would become a pain. There is a reason all (most) operating systems are written in C.

Years ago I came accross a book about writing MS Windows programs. MFC and all that. However this book was showing you how to do it in x89 ASM rather than C++. At the time I found it easier to understand than the all that C++ junk.

Thanks for the link, I will check it out. Does x86 dex-os run on any real bare metal systems, like an 8086 board or so?

[DexOS]

Thanks for the link, I will check it out. Does x86 dex-os run on any real bare metal systems, like an 8086 board or so?

Yes it will run on any x86 sys, from 486 up to the latest sys as long as it still uses BIOS for booting.

It can boot using floppy, cd, hdd, usb, also it can boot from Dos.
See here for how to: http://www.dex-os.com/Doc/DexOS_Building_Installing.txt
This is it booting from a x86 computer the size of the PI
http://www.youtube.com/watch?v=mYJx2zZK7c8

Its called a eBox 3350MX
http://robosavvy.com/store/product_info ... ts_id/1704

[mahjongg]

Note that connecting a propellor chip to the PI (using the PI's UART) is a good way to interface a keyboard and a mouse to a PI, without the need to use USB, or the need to interface keyboard and mouse directly to the PI.

On the propeller you only need to hook up two mini_DIN connectors to the propeller, and use some existing code for PS/2 keyboard, serial mouse and UART communication interfaces, (you can also use existing board designs, as many of them has the right connectors, for example the "Hydra" board, or one of the many open hardware designs, but its also easy enough to wire it up on a piece of perfboard) then you can design a protocol to send data packages with keyboard and mouse data over the serial connection to the PI, where you split the packages in two streams, one for the keyboard and one for the mouse. That way you only need the one UART on the PI for both keyboard and mouse I/O.

[DexOS]

Note that connecting a propellor chip to the PI (using the PI's UART) is a good way to interface a keyboard and a mouse to a PI, without the need to use USB, or the need to interface keyboard and mouse directly to the PI.

On the propeller you only need to hook up two mini_DIN connectors to the propeller, and use some existing code for PS/2 keyboard, serial mouse and UART communication interfaces, (you can also use existing board designs, as many of them have the right connectors, for example the "Hydra" board, or one of the many open hardware designs, but its also easy enough to wire it up on a piece of perfboard) then you can design a protocol to send data packages with keyboard and mouse data over the serial connection to the PI, where you split the packages in two streams, one for the keyboard and one for the mouse. That way you only need the one UART on the PI for both keyboard and mouse I/O.

Nice, thanks for the info, i new you could do this with the arduino, but it seems just as simple with the propellor chip.

[liz]

One of our interns has written a lovely intro to bare metal on the Raspberry Pi as his summer project. He's polishing it at the moment, but I'm hoping to get it on the front page next week.

[W. H. Heydt]

Theres a common belief that people only code in ASM to optimize code for speed or size, but there are some crazy people out there that actually like coding in assembly, we are control freaks and these very same control freaks are also the the type to code there own OS

While I have been toying with the idea of learning the assembly language of the Pi (with an eye to translating a program I once wrote in ALC on a 360/50 to completely solve the Soma Cube...it took 4 hours to run...), I might be more enthusiastic about going back to using such languages if I hadn't spent some time maintaining an 11,000 line assembly program that was the main posting program for demad deposit application....

[DexOS]

One of our interns has written a lovely intro to bare metal on the Raspberry Pi as his summer project. He's polishing it at the moment, but I'm hoping to get it on the front page next week.

Great look forward to that, it will be cool to get some bare metal on the front page.

[adlambert]

One of our interns has written a lovely intro to bare metal on the Raspberry Pi as his summer project. He's polishing it at the moment, but I'm hoping to get it on the front page next week.

Is it this by Alex Chadwick?

http://www.cl.cam.ac.uk/freshers/raspbe ... orials/os/

Looks like the best thing I've found to do with the Pi so far, for my interests as I am not a fan of slow lumbering linux GUI. Please pass on my thanks and congratulations to him, this is brilliant!