GP2X Random Tough About Sd Card And External File System

[paxl13]

Hi all,

I'm owning a GP2x since the begenning of the summer
and playing with my little friend a lot. I adore, love, admire,
Mslug and Gngeo. Lately I wanted to start to program so
I compiled opoo toolchain and start to do card swapping
and I realise ok.. this is slow so fuck it.. Since I'm in linux
since a long time i tought .. NFS.. setupped it and I can't
get it mounted on the '2x side, so that my first question
is it possible to do nfs mounting with gp2x FW 2 out of box ?

after messing up with things I downloaded the samba package
and installed it.

smbmount ... and it worked.. so great deal.. usb2 full speed.. great.

And then I remeber have seen on the forum that the SD card was
a big bottleneck in the emulator that uses large roms. like NeoGeo.

So I tryed GnGeo over samba and linux. I tryed metal slug 3.. ' the
worst.. ' and at oc 240 + sound and it worked at 60 fps with NO LAG
at all. So, I think this show that my SanDisk 2GB [ not ultra.. a standard
one ] Is realy too slow. So is that normal because my sd card in my reader
can push ~3 MB/s to the card.

Is there anything like DMA that can help sd card transfert at the linux
kernel height.

Thanks for your answers and toughs
paxl13

 

[DJWillis]

Is there anything like DMA that can help SD card transfer at the Linux
kernel height.

Welcome to one of the main GP2X flaws. MagicEye's have said that to all intents and purposes DMA transfers for the SD interface are broken on the MP2520F (MMSP2) SoC used in the GP2X.

Most fast cards use DMA mode so that is why the top end cards do not make a huge difference in the GP2X.

There has been some work done to see if anything can be done to get more speed out of the SD interface but if you use DMA mode as the docs tell you start to get corruption and problems in the most odd of places.