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

[spark]

[[V1 requirements]]

[1 or 2 outputs?]
1 stere o/p should suffice. you can anyways plug a Y splitter externally to have 2 headphones.

[wireless connectivity?]
Bluetooth is a good option. For hardware all we may need is a SPI bluettoth chip. i dunno how r we gonna implement the bluetooth software stack on the player. It will be challenging.

[Built-in storage]
The main purpose of built in storage is to hold the firmware. But it doesn't hurt if we have some more space here to accomodate some media files.

(available options NOR, NAND, SPI)

SPI is not an option as it is restricted to a few MB's with very high price/MB.

NOR is expensive whhen compared to NAND.  Again restricted to less than 64MB

NAND has lowest price/MB.
the AT91 supports NAND bootloader. NAND is cheap and available in higher capacities with lowest price/MB. in fact the 8GB SD card we r talking about also uses NAND chip/s iniside.
1GB internal NAND is the best value for money for now. by the time we're in production, 2/4GB should be appropriate. Nothing changes in the hardware. just need to solder the cheaper/bigger chip.

[CAD tools]
gimme an option to use Orcad Layout and i'll get the PCB done in a week's time. we can later re-design using kiCad. atleast we'll get the concept proven.
jokes apart. maybe we'll have to learn kiCad(PCB).

[casainho]

The Sansa e200 you use as comparison has both internal NOR and NAND, so I'm not sure this clarifies anything...

I didn't know that - I were at IRC asking about that and also did read the TWiki page about Sansa E200 hardware. Bagder, so, Sansa boots from NOR? where is the RB bootloader? on NOR flash or in NAND flash?

[[V1 requirements]]

[1 or 2 outputs?]
1 stere o/p should suffice. you can anyways plug a Y splitter externally to have 2 headphones.

Ok with 1 input.

[wireless connectivity?]
Bluetooth is a good option. For hardware all we may need is a SPI bluettoth chip. i dunno how r we gonna implement the bluetooth software stack on the player. It will be challenging.

If Bluetooth is interesting but we don't have RB code for that, we can put that on V2...

[Built-in storage]
The main purpose of built in storage is to hold the firmware. But it doesn't hurt if we have some more space here to accomodate some media files.

(available options NOR, NAND, SPI)

SPI is not an option as it is restricted to a few MB's with very high price/MB.

NOR is expensive whhen compared to NAND.  Again restricted to less than 64MB

NAND has lowest price/MB.
the AT91 supports NAND bootloader. NAND is cheap and available in higher capacities with lowest price/MB. in fact the 8GB SD card we r talking about also uses NAND chip/s iniside.
1GB internal NAND is the best value for money for now. by the time we're in production, 2/4GB should be appropriate. Nothing changes in the hardware. just need to solder the cheaper/bigger chip.

So, let's go with the cheaper NAND flash knowing that as minimum we need 8MB.

[CAD tools]
gimme an option to use Orcad Layout and i'll get the PCB done in a week's time. we can later re-design using kiCad. atleast we'll get the concept proven.
jokes apart. maybe we'll have to learn kiCad(PCB).

If we can do that first in Orcad and later in Kicad, why not? :-) - but we have time for working, first there will be the PrototypeB, I will learn a lot with that proto :-)

[Bagder]

Sansa boots from NOR? where is the RB bootloader? on NOR flash or in NAND flash?

But it's no point in discussing how the Sansa boots. When we write bootloaders for Rockbox for whatever target we work on, we adapt that method to how the original system is designed and how it works.

When you create your own player you can decide yourself how to boot and you don't have to inherit any weird systems you can see Rockbox use on existing players.

The Sansas boot first from NOR, then it loads a bootloader from NAND and then that bootloader loads the firmware from NAND. In Rockbox's case, we replace the firmware with our bootloader which then loads Rockbox...

[casainho]

When you create your own player you can decide yourself how to boot and you don't have to inherit any weird systems you can see Rockbox use on existing players.

The Sansas boot first from NOR, then it loads a bootloader from NAND and then that bootloader loads the firmware from NAND. In Rockbox's case, we replace the firmware with our bootloader which then loads Rockbox...

I am new to this systems, I am trying to learn looking at other's work.

From what you said, I assume that in Sansa E200, RB bootloader is in the NAND and the firmware is in FAT32 on other part in NAND. RB have 2 parts, a bootloader and a firmware? both in the same NAND ic but in different parts,  partitions?

With the choosed MCU for RB Player, it bootloades from a NAND flash, so we just need to write RB bootloader + firmware for FAT32, as in Sansa E200 NAND flash ic, we don't need to use one more flash IC, the NOR, as Sansa use, thanks to bootloader that already resided on choosed MCU for RB Player. This is my thoughts :-) - I am learning a lot in this process :-)

[Bagder]

If I were to design a NAND based played with this MCU, I'd certainly have an internal NAND of 1 or 2 GB and then there would be a partition of that saved for the bootloader. I would then also try to make that bootloader to be u-boot, as that would make a lot of development easier.

And yes, that excludes the need for a NOR flash since the at91sam thing can boot off NAND.

[Davide-NYC]

Hello all,
I posted my enthusiasm for the stereo line-in *plus* toslink input jack (like the h1x0) here.

If this player does get made an optical in (for recording) would be amazing.

[casainho]

I talked today with Matt about RockboxPlayerPrototypeB. He delayed it to the summer time. Also he talked something about his school project(RockboxPlayerPrototypeB) being a combination project, an oscilloscope and an mp3 player.

Since he changed the schedule of the RockboxPlayerPrototypeB, for a few months later, I will not wait for he end his project. I want to have hardware before that, to start coding - maybe in the next 4 weeks.

I would like to ask If anyone have some idea for a good route to the project. If no better idea than the last one, the RockboxPlayerPrototype, I will continue with that RockboxPlayerPrototype.

[spark]

[bootloader]
I agree with Badger. We just use a resonably sized NAND chip. use a u-boot bootloader. (advangate of u boot-->we just have to do some configuration stuff and need not write one from scratch).
the u-boot bootloader will then load RB from again NAND itself.
This way things are simple.

[project route]
We should first get the stuff working on RockboxPlayerPrototype (i.e. eval board + expansion board). I can design and fabricate the expansion PCB. I'll send the PCBs across to anyone interested for assembly.

casainho, since you already have the dev board, you can start doing some coding on it. 1st step is to finalize the booting plan. i guess the above mentioned booting method is fine.

we have to start somewhere otherwise things will just keep delaying.

[casainho]

[bootloader]
I agree with Badger. We just use a resonably sized NAND chip. use a u-boot bootloader. (advangate of u boot-->we just have to do some configuration stuff and need not write one from scratch).
the u-boot bootloader will then load RB from again NAND itself.
This way things are simple.

[project route]
We should first get the stuff working on RockboxPlayerPrototype (i.e. eval board + expansion board). I can design and fabricate the expansion PCB. I'll send the PCBs across to anyone interested for assembly.

casainho, since you already have the dev board, you can start doing some coding on it. 1st step is to finalize the booting plan. i guess the above mentioned booting method is fine.

we have to start somewhere otherwise things will just keep delaying.

Okok, lets continue then with RockboxPlayerPrototype!

I didn't buy yet the dev board :-) - I just bought and have with me, the JTAG cable to program the ARM and the LCD+carrier board.

Don't worry Spark, I will make the expansion PCB, I hope to have It in the next 3 weeks. I will fabricate It and send them to developers. In the right time I will announce that and wait for request from interested developers.

I will update the wiki pages in this times and I will buy the dev board also.

I will need help to make the bootloader, I don't know nothing about u-boot :-) - Will be important to have other people doing the same work.

Project License
What should It be? - I wrote GPL2 on wiki page, however I don't know If is the better... I chose that because RB firmware uses that.

For me, a BSD would also be ok. I remember that a CC No Commercial didn't had a good reception, when Matt chose that for the RockboxPlayerPrototypeB.

I don't believe in Copyright this hardware, for example, copyright the way to wire a memory to the MCU, and since this is an hardware project, I really don't believe that If we copyright It will have any effect, other then show to others ours interests in sharing It and that anyone are free to reuse It.

[spark]

[bootloader]

There will be only 1 stage of bootloading.
On power ON, the bootloader starts from NAND. The job of this bootloader is to initialize hardware and load the RB firmware into memory from somewhere (again NAND partition) and execute it.

one option is to use u-boot, the second one is to write a simple bootloader from scratch.

Getting u-boot to work will take some efforts but it does make life a lot easier in the long run. If we get u-boot to work, we can do things like updating application firmware over serial or network, creating partitions, checks, etc without using JTAGs. u-boot comes with ready NAND driver, ethernet driver, tftp boot support and filesystem support (fat,ext,jffs, etc)

u-boot is already ported for the AT91RM9200 board. we will have to use this as reference. don't worry casainho, i can give u-boot support. i have some experience with it.


[license]

I think we shouldn't worry a lot if people use it commercially or no. The more the people use it, the better it is for us.

[Bagder]

I don't believe in Copyright this hardware

Now don't confuse copyright with using a free software/hardware license. Everything done can and probably should still be copyrighted fine by the authors of it, but the license should probably be free and open to allow both commercial and non-commercial use of everything. Both because that's what Rockbox does but mostly (IMHO) because that's the spirit we all work on this under.

[casainho]

the license should probably be free and open to allow both commercial and non-commercial use of everything. Both because that's what Rockbox does but mostly (IMHO) because that's the spirit we all work on this under.

Nice to have your opinion about this subject. So, GPL2 is appropriate?

Draw a schematic to wire an flash memory to an MCU and after copyright it with an GPL2 license, does it have any practical effect? Can someone copy It and use without apply GPL2 license?

[Bagder]

GPL2 is appropriate?

Sure, the entire Rockbox source code chunk is GPL2 (the debate is weather that is "v2 or later" or just "v2")

Draw a schematic to wire an flash memory to an MCU and after copyright it with an GPL2 license, does it have any practical effect?

You don't "copyright it" with a license. You copyright it, and then you release it under a license and that license can indeed be GPLv2.

Can someone copy It and use without apply GPL2 license?

I'm not a lawyer, but the whole purpose of GPL is to make sure nobody denies anyone else the source code and ability to build and distribute their own copies and derivates of the original. So no, you can't get the schematic and just "shave off" the license, that's not permitted by the license.

[casainho]

GPL2 is appropriate?

Sure, the entire Rockbox source code chunk is GPL2 (the debate is weather that is "v2 or later" or just "v2")

And why not V3?

Draw a schematic to wire an flash memory to an MCU and after copyright it with an GPL2 license, does it have any practical effect?

You don't "copyright it" with a license. You copyright it, and then you release it under a license and that license can indeed be GPLv2.

Can someone copy It and use without apply GPL2 license?

I'm not a lawyer, but the whole purpose of GPL is to make sure nobody denies anyone else the source code and ability to build and distribute their own copies and derivates of the original. So no, you can't get the schematic and just "shave off" the license, that's not permitted by the license.

Okok, my ideas are more clearly now, thanks. So for me, using this kind of license is important!

[GodEater]

And why not V3?

Because it's debatable whether or not it would then be license compatible with everything else that Rockbox has licensed.