Re: [gp32linux-devel] [GP32linux] Linux GP32 port

[Lucas C. V. R. <lu...@go...>]

On Wednesday 15 June 2005 11:09, Hector Oron wrote:
> Hello !

Hi there,

>   I'm new to this list. I have been looking for a target platform to get
> some stuff done with this little systems. Development boards are very
> expensive, and i have found out that GP32, it's awesome, it ships with a
> ARM9 with MMU and a nice screen, also it has good conectivity. I've been
> thinking and i've booked one GP32 at one store arround.
>
>   I'm very interested on linux port for GP32. I've spent a couple days
> searching forums and webpages (firmwares, bios, etc...) and i have some
> things i haven't cleared it out.
>
>   First of all, i've been hearing that GP32 is an opensource tool, but
> is it openhardware, are there some schematics arround or developing
> linux documentation (besides the datasheets)?

The schematics (s3c2400 datasheets) are all freely available. The only problem 
relies on the SmartMedia datasheets, which are proprietary, but they can be 
easily find on the web.

>   I've also been reading that 2.4.13 is working already, but what about
> 2.6 series. I've seen Lucas patches, but are they working or are they
> buggy ?
>
>   What is the status for drivers ? What are working drivers ? USB (i
> think it could work as a host), Wifi, etc...

2.4.13 is fine, with both USB host and USB device support. I'm commiting 
2.6.12 patches directly into the mainline kernel (gp32 support is going to be 
shipped on the official Linux release).

2.6 is not working fine yet; I've finished the base port (clocks, uart, i2c, 
dma, irq, etc) and have rewritten the bootloader, moving a lot of 
initialization code from the machine in the kernel (2.4.13) to it.

Currently it's just sending some debug strings through the UART to my minicom 
session. I needed to freeze development some weeks, since I moved to a new 
home. I'm now stable and have my computer working fine on my new appartment, 
but I still lack an internet connection (I'm going to ask for a phone line 
today). 

Until then, development will go a bit slow, since I need to keep communicating 
with Ben Dooks (s3c2410 maintainer, used by iPaq and some other machines) 
while merging the patches.

>   Why do you use linux kernel, have you think about using uclinux kernel
> ? Are you compiling against glibc, uclibc, dietlibc ? what about X ?
> using nanoX or some other software ? could you write to framebuffer
> directly ?

I'm using Linux kernel because we have a MMU on the s3c2400. However, I've 
seen some reports where the uClinux kernel had a great speedup advantage over 
Linux for an architecture MMU-enabled. IIRC, this was on a Sony camera, on  
LinuxDevices.com. It might be cool to work with uClibc later, but I'd like to 
finish the Linux port before doing that.

>    How do you flash the board ? with JTAG ? or using some hack with SMC
> (btw how is the driver working and is it possible to use adapters) ?

I'm not flashing it. I'm keeping the BIOS as it is; the bootloader was written 
as a game, so one can still use its GP32 to play games. The bootloader and 
the kernel image are uploaded as usual (with gplink or with a SMC card 
reader/writer).

>    And, finally, for cross-compiling, are you using sbox, buildroot, ... ?

I'm using a toolchain taken from CodeSourcery.com which works just fine.

>   Anyways, would you recommend me to get one of those GP32 ? I hope
> so...  (c:

As a gaming environment, there's some more interesting consoles with more 
games available. However, it seems that the GP32 community is much nicer than 
these others.

As a development target, the GP32 is just great - there's many SDKs and source 
code available, and the hardware is also not hard to understand. I just 
became an ARM addicted after started playing with it, so it's hard not to 
recommend it for you ;-)

Cheers,

-- 
Lucas
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