lundi, juin 06, 2011

Welcome, libfat 1.0.9

While I was busy on a tons of things (including building up the first prototypes of AnimEDS) in february, Wintermute and his friends at devkitpro did a major revamp of the libfat, separating "what's good for the DS" from "what's good for the Wii". When it comes to mass storage performance, the two beasts are strongly different ... L1 cache, data transfer speeds, amount of L2 memory ... The release (1.0.7) I used in my "dkp-r32" setup tried (and failed) to provide a uniformised solution. I tried a few hacks that at some point looked to improve the performance, but didn't find the time to quantify the boost in a systemic way. I offered a patch, but ignoring the project's habbits made it doomed to /dev/null.

Hopefully, the new build seems to provide good performance again (PC->AP->DS transfer rates of 64-80KB/s at home).

Oh well, one annoying difference remain: i *have* to apply a DLDI patch manually for SCSD device (which used to have a built-in driver in former libfat). I also have an issue with directory scanning ... I hope it won't take too long to figure out what it is. it looks like I underestimated the MAX_FILENAME_LENGTH ... again ...


J'étais tellement à la bourre en février que j'ai complètement loupé la sortie de la version 1.0.9 de la libfat. Heureusement que je suis repassé jeter un oeil sur le forum de devkitpro après avoir tenté de refaire le point sur l'état du cache la semaine dernière, sinon j'aurais bêtement perdu plein de temps. Enfin, donc, une version qui traite la DS indépendamment de la Wii et de la gamecube, même si j'ai du ruser pour contourner les problèmes de __io_dsisd manquant et patchouiller mes programme pour m'ajuster à une augmentation de MAX_FILENAME_LENGTH visant à améliorer le support d'UTF8. Enfin, c'est réglé.

Une vitesse de transfer entre 64 et 80kB/s (@home en utilisant le wifi entre le PC et le routeur et entre le routeur et la DS), c'est tout ce que je demandais.

Bon, maintenant, 'faudra que je regarde comment faire en sorte que ma fonction die() marche à nouveau ...

(PS: oui, j'ai testé tout ça sur la PHAT de ma fée, histoire de limiter la casse et les pertes de données au cas où... honte à moi ^^" ... quoi que, avec le binaire de SEDS qui crèe systématiquement des fichiers de taille 0 datant de janvier 1979 ...)

4 commentaires:

WinterMute a dit…

You don't *have* to manually apply a DLDI patch, there's a way to get it to autopatch. Remember this post? http://devkitpro.org/viewtopic.php?f=24&t=2384&p=6457&hilit=autopatching#p6456

sylvainulg a dit…

@wintermute: yes, now I remember, and the scsd.dldi version I'm now using comes from there ... I just missed the fact that it was a firmware upgrade, somehow :P

Thanks for reminding me again.

sylvainulg a dit…

and if I read homebrew menu changelog correctly, readdir has finally been implemented in libfat and I no longer have to rely on dirnext and figure out whether libfat::FILENAME_MAX_LENGHT == syslimits::NAME_MAX+1 is maintained or not.

sylvainulg a dit…

(soon to appear in my todo list as well ?