Rockbox Player - Project to design and build a Free/Open hardware audio player

[casainho]

There is a new developer :-)

> From: "Aditya Gandhi" <>removed
> To: removed
> Date: Fri, 10 Oct 2008 02:19:32 +0530
> Subject: Rockbox Player
> Hello there, I'm Aditya from India. I've ordered a Olimex 9260 board for developing the rockbox player, I'm a novice with arm. Can u help me get a kick start with this. I'm really sorry for this abrupt mail, but I've taken this player as my project in college and really want to help the community develop this hardware. I even plan to make the jtag myself for this, can u suggest a few books or links where I can start on this board/platform. Anything relative, I've read about this processor, its architecture but I'm just a guy who works on robots with 8-bit processors and assembly.....
> Any kind of help will be of great help. Hoping for a reply.
> Thanks in advance.

I've removed all traces of e-mail addresses from this message - BigBambi

[notlistening]

Whats happened:

1. Well we have gained another developer from india making us a threesome
2. We are a little bit stuck at the moment getting the rockbox bootloader to work on the dev board if there are any AT91 developers out there that might be able to help we would appreciate some guidance.
3. Just been updating the http://code.google.com/p/rockboxplayer/ pages to help any new comers to understand what been going on and how to join in.

Tom

[casainho]

EDIT on 2008.10.22:

A new developer joined the team:

AlexCantos - also AJCantos. Joined as a developer in October 2008. EXPERIENCE: I work in a small audio electronics company. My skills include hardware, embedded software and some mechanical design. I CAN HELP IN: I can develop/test/improve hardware, implement software and do some visual/conceptual design. MOTIVATION: I love audio electronics, gadgets, open source and Rockbox, need any more reasons?

I might explore some of the advantages of AVR32 over the atmel arm9 board. The ngw100 board makes a sound choice for now. I can mark up an AVR32 64-TQFP (at32uc3b chip) with an adapter into a project. It just has full speed usb and 60 MHz max. frequency. For now, it looks to be my better choice, sorry guys. The ngw100 board is $73 usd from mouser and many specs that I'm looking for in a learning project and still uses the same tool chain. Very useful, hope you agree.

I do not agree :-) eheh - At first I wanted to use that MCU and that board, until RB developers explained that RB source is prepared for ARM, because of assembly optimizations and so on.

I really like the idea of AVR32, I am being working with AVR USB and also I am looking with other persons to do a kind of dirty cheap DIY AVR32 board :-)

And yes, Arduino is great, GCC is great, all this Free Software tools and Atmel MCUs are great ;-) -- go to have a look at AVRopendous and MyUSB Lib.

2. We are a little bit stuck at the moment getting the rockbox bootloader to work on the dev board if there are any AT91 developers out there that might be able to help we would appreciate some guidance.

I think that any developer with knowledge on ARM assembly and C start up code would easily be able to help as at this moment (not need to be on AT91 MCUs)...

[Bagder]

I'd like to repeat here what I've repeated in the IRC channel for the last times this target has been discussed:

If you guys would simply produce good patches against current Rockbox SVN and post them, like in the patch tracker, you'd get much more people who'd read your work and who'd easily could try out building the stuff for your target. And possibly help out fixing flaws in your build setup, lds scripts, makefiles, crt0.S files or whatever.

You need to bring your code to the Rockbox way of life, rather than sit in your own corner of the internet trying to lure over Rockbox hackers.

You'd also be sure to work faster and more in a straight line towards integration in the main Rockbox source code, which I assume is something you want.

[casainho]

I'd like to repeat here what I've repeated in the IRC channel for the last times this target has been discussed:

If you guys would simply produce good patches against current Rockbox SVN and post them, like in the patch tracker, you'd get much more people who'd read your work and who'd easily could try out building the stuff for your target. And possibly help out fixing flaws in your build setup, lds scripts, makefiles, crt0.S files or whatever.

Unfortunately I don't know how to do patches nor how to post them - but I think Tom may know that so I would ask him to do it.

Now we are stuck on a problem that first occurrence of interrupts hangs the system - I believe the problem is within linker script, C startup code or even the version of GCC used to build Rockbox that is different of that used to build our Flash_LED code.

Was we are looking for guidance, I appreciate your help on saying this again Bagder, we will do it for sure. Thank you  

[bluebrother]

Unfortunately I don't know how to do patches nor how to post them - but I think Tom may know that so I would ask him to do it.

I'm pretty sure you have been directed to the WorkingWithPatches wiki page before, so this is no excuse (and not finding the man page for "patch" neither) ...

You should really learn how to use those tool as they are essential if you intend collaboration with the core rockbox development.

Oh, and developing for a microcontroller is quite different than developing on a host system, so reading up on SVGAlib would be simply a waste of time (it could be an interesting read though, but it won't help for embedded programming itself -- for that a strong knowledge of the language C is much more helpful).

[notlistening]

That's right, ask Tom,

Well the situations is that we are all new to rockbox and in varying degrees, the whole development process. We are trying to get up to speed, I am reading and digesting as much information as possible, please bear with us.

Tom

[bluebrother]

example: http://www.mingw.org/

What kind of pointers do you expect? That page is about a compiler and tools collection for windows. You can use that for building windows programs (for example, Rockbox Utility is build using MinGW), but it is not an introduction to programming. If you want to learn programming directly on Rockbox, get the documentation and do actually something on Rockbox. For starting modifying / extending / writing a plugin is usually a good idea. And for learning C ... the "bible" is "The C programming language" by Kernighan and Ritchie (often referred as K&R) though this is not an introduction but rather a reference, so for a start take any reasonable C tutorial.

To learn C (as with any programming language) you should bring time, start hacking and share what you did with others -- as in go extending an existing Rockbox plugin and discuss your changes with Rockbox devs. The best way to do this is to come around to IRC. And it's vital that you learn how to share your changes. Only this way you can take advantage from others knowledge and most likely have a much easier start than when doing everything in your own corner. That's basically what Bagder already said ...

[casainho]

Today we got the first bootloader code working Now it flashes a LED, using interrupts, and sends data to serial port. Next task is to put RB kernel working (using the interrupts) and use the "sleep(int ticks)" from kernel, to flash the LED.

Alex is designing the expansion board that will have the LCD, buttons and the audio DAC. Soon we will start working on drivers for the LCD

We have being 3 active developers on last weeks, me, Tom and Alex. We were stuck on a problem at linker script and interrupts but today we resolved it.

I am being reading about Eclipse, GNU Debugger, OpenOCD and JTAG debugger hardware integration. So, preparing my debug tools to work a lot on the Player

[Dark Horse]

Hello everyone
I have no programming experience but have been folllowing this thread with a great deal of interest for a while. I have a friend who works in the engineering dept at freescale if you are still considering the freescale processors I will see what might be available thru him. (information programming hard ware etc.)

[casainho]

JTAG debugging and Eclipse IDE

I was able to do Debug using JTAG and Eclipse for the first time :-) Eclipse is great because we can save the project and setup all external tools as for loading code to SDRAM and run it or the external tools to do debug as the OpenOCD. Every developer can then use the project without the need to reconfigure that external tools on Eclipse. Here is one screenshot:

Hello everyone
I have no programming experience but have been folllowing this thread with a great deal of interest for a while. I have a friend who works in the engineering dept at freescale if you are still considering the freescale processors I will see what might be available thru him. (information programming hard ware etc.)

Hello :-)

Thank you. We are working with an ARM MCU from Atmel, as selected since the beginning because good application notes with free code, it's being proving valuable in our task because we are beginners in ARM and we also need to use Free Software tools (and have documentation about using them) since we are not professionals.

I am being learning a lot and I am happy

[Tirithen]

This is so great, I was wondering if anyone was trying to do something as crazy as trying to build i'ts own hardware for rockbox and I found out that you are. I myself only have some small experience of programming 8-bit pics to control servos and leds so I don't know if I could be of much help but i would love to see rockbox running on open hardware and I would definently buy one! Keep up the good work and merry christmas!

[casainho]

This is so great, I was wondering if anyone was trying to do something as crazy as trying to build i'ts own hardware for rockbox and I found out that you are. I myself only have some small experience of programming 8-bit pics to control servos and leds so I don't know if I could be of much help but i would love to see rockbox running on open hardware and I would definently buy one! Keep up the good work and merry christmas!

Hello :-)

We really need more developers!! If you really "would love to see rockbox running on open hardware", please consider in joining our efforts, you can start by reading the GettingStarted page.

I also work professionally with 8 bits microcontrollers... I am learning a lot :-) -- you can see more about me here.

Merry Christmas to every one

[Llorean]

Why do you have so many pages at your Google code site that either duplicate, for example, how to set up the development environment, or simply contain information that should be hosted on the Rockbox wiki? Why not chart your progress on the wiki here, where it can more easily be in the site of other interested Rockbox developers?

Is your intent to create a new project, or actually work on Rockbox?

[casainho]

EDIT on 2009.01.10:

I got the first messages written on LCD :-) and I must say that the fact it's a wide known LCD used on almost every cheap Open Source hardware project did help me a lot to make it working!!

There is some issues that I will resolve on next days. Here is one image showing the LCD and the message "Rockbox Player Bootloader":



EDIT on 2009.01.03:

Finally Rockbox kernel is working :-) Yesterday I did put it working and flashing the green LED using the sleep(HZ).

On last days I were stuck with a problem, I was getting a data abort interrupt (the same I was having before and taught it were SDRAM bad initialization), because some data structures were with wrong memory address values. I did use JTAG a lot to understand this. I asked and showed some screenshoots of debuging on Rockbox IRC channel, some one gave me some clues... the problem was that data structures weren't getting zeroed... and I did understand that not all bss section (initialized variables) were zeroed on C startup file... was missing on linker script to add the section COMMON, a section that I didn't know that existed, since is from Rockbox source.

Here is one image showing the code of initializing Rockbox kernel and flashing the green LED using sleep(HZ):



EDIT on 2008.12.31:

I started again the work of porting the code and now I created a patch for it against Rockbox source. That patch is now on our code.google SVN and is the way for now build the project port. I updated the GettingStarted wiki page with this information and deleted from SVN the other out updated code.

Today I got the bootloader code building but it was hanging on panicf() and after on system_reboot()(empty function for now). Doing debug and reading the code comments, I did understand that I need to "Set up some stack and munge it with 0xdeadbeef" on C startup file crt0.S, as on other ports :-) Here is one image of debug window:

Why do you have so many pages at your Google code site that either duplicate, for example, how to set up the development environment, or simply contain information that should be hosted on the Rockbox wiki?

It's a wiki page, it started to have information that weren't on RB wiki, as setup another Lib that is not used by RB but is used by bootloader.

But yes, now it's duplicated however it can have something other that can be needed in future...

Why not chart your progress on the wiki here, where it can more easily be in the site of other interested Rockbox developers?

I am doing it, here.

Is your intent to create a new project, or actually work on Rockbox?

NO!! We need to have our playground for development, our SVN. RB SVN can't be used by us, we can't commit to it. For example, I am a beginner on ARM and C... Soon as we have something working, like LCD drivers, maybe on that time we can post some patches to RB tracker.

I really like all tools and information at Rockbox, the forum, the IRC channel and logs, the SVN, the Wiki, etc. We really have advantages on stay together, however for now we will use our SVN, it's a kind of temporary.