Cowon D2

[linuxstb]

Have you enabled the cache yet?  I had similar very slow speeds before enabling the cache on my Telechips port - and about a 15x increase in speed when it was enabled.

Maybe the unreliability you're experiencing are due to timing issues - maybe they will fix themselves if you clock the CPU the same way as the original firmware, and also enable the cache.

[shotofadds]

You're more than likely correct. I've been looking at the OF again and the PCF50606 init sequence does happen after the cache has been enabled. Its I2C timing mechanism is a simple null loop, so I suspect my rudimentary attempt at mimicking it is quite some degree out with the cache turned off.

I think a problem with the LCD panel startup is less likely as I've set up a simple 1ms timer for those (timers on the 7801 look to be the same as 76x with a different base address). It should be fairly straightforward to verify the timer works, as I can see printf output when I press the reset button.

My biggest challenge is to find some free time over the Xmas period though...

EDIT: Enabling the cache makes a significant difference (at least 10x speedup), but I still can't make the LCD come on. More investigation required methinks.

[shotofadds]

Problem solved - I was sending the wrong command to initialise the backlight. I'll get the code tidied up and submit an initial patch, though I doubt this will happen before 2008

This provided some enlightenment (thanks Bagder for the pointer):
http://svn.openmoko.org/trunk/src/target/kernel/patches/gta01-pcf50606.patch

[sastraxi]

shotofadds, if you're willing, I would love a copy of the register/interrupt address information you've already gathered from your D2 to help with the reverse-engineering process. I couldn't find this information on the wiki so I suppose you're pretty busy.

[shotofadds]

I haven't added anything to the wiki yet, since those details will eventually be available by reading the source code. Having said that, I'm about to add a section describing some of the GPIO ports as I think that's best documented on the wiki. Check back soon, there should be some info for you to digest.

EDIT: I've spent the last hour or so doing a brain-dump into the wiki. Enjoy!

[sastraxi]

That's amazingly helpful, thanks. However looks like I'm running into the time wall as well -- I'll see if I can't make this sucker output something in the form of sound in the next few weeks, though. Let us know when you submit the patch; I'd love to have a base to work on rather than doing the work you've already done over again!

[paradox]

Hi,
do you think the Telechips docs and SDK could be useful?  
They seems to be freely available on the web:  
(here TCC77x, TCC78x and TCC82x, TCC76x on request...)

TCC77X.pdf
TCC7821_chipspec_r0.03.pdf
TCC7801_chipspec_r0.03.pdf
TCC7820_chipspec_r0.05.pdf
TCC7821_chipspec_r0.01.pdf
TCC7830_chipspec_r0.11.pdf
TCC7831_chipspec_r0.03.pdf
TCC780_DataSheet_r0.09.pdf
TCC8200A specification r0.pdf
DMP77X_1800_Utility.zip
DMP77X_1800_Manual.zip
DMP77X_1800.zip
TCC77x_PWS_ADS_V100.zip
DMP77x_Audio_Codec_Manual_v1.2.zip
TC-TCCxxx-ALL-AG-1000-1.00-ADS Compiler Patch Guide_Eng.pdf
DMP77x_1200 DAB patch V0.01.zip
DMP77x_DAB_API_manual_r0.01.pdf
DAB_1027_patch.zip
DAB.zip
TCC78XX_4CS_NANDBoot_HW_AN_8723_V0.10_ENG.pdf
TCC78XX SUB Board.zip
TCC7820_30 Mobile.zip
TCC78xx_MultiMedia_Application_SDK_v044_release.zip
Mobile Manual.zip
TCC7820-7830 Hardware Data files.zip
readme.zip
MAP78X_NUCLEUS008_NFS059_V0709281579.zip
TCC78xx_DMP_PortableManual.zip
SDK_Before02.zip
SDK_Before01.zip
TCC78XX_4CS_NANDBoot_HW_AN_8723_V0.10_ENG.pdf
TCC78XX SUB Board.zip
TCC7801 Portable.zip
SDK_Before.zip
TCC7801 Hardware Data files.zip
TCC78XX_4CS_NANDBoot_HW_AN_8723_V0.10_ENG.pdf
TCC78XX SUB Board.zip
readme.zip
DMP78X_NUCLEUS009_NFS064_V071130641.zip
TCC78xx_DMP_PortableManual_DMP641.zip
DMP_SDK_Before_02.zip
DMP_SDK_Before_01.zip
TCC78XX_4CS_NANDBoot_HW_AN_8723_V0.10_ENG.pdf
TCC78XX SUB Board.zip
TC-TCC82x-DMP-AM-1000-1.00-TCO(PWM) Errata.pdf
DMP82X_2200.zip
DMP82x_DOC_v2200.zip
TCC82x_PWS_ADS_V100.a
TCC8200_DEMO_DED_AM_2715_V0.13_ENG.pdf
TCC8200_DEMO_DED_V0.13.zip
TC-TCCxxx-ALL-AG-1000-1.00-ADS Compiler Patch Guide_Eng.pdf
TCC8200_DEMO_DED_V0.12_SCH.zip
TCC8200_πË∆˜øÎ_PDF.zip

Happy new year and happy hacking!
Looking forward to have Rockbox on the D2 soon
--
Security through obscurity is a great idea

[LambdaCalculus379]

Holy crap, paradox... that's a mountain of information!

Can you post all of that to the wiki so it won't get lost, please?

[paradox]

Sure, but I need a wiki account first...
Is there some webspace where we could mirror those files?
We certainly don't want to slashdot their website?

[LambdaCalculus379]

You can set up a temporary FTP account and host them there.

Actually, don't post them to the wiki... legal reasons, you see.

[shotofadds]

I suspect these links will stop working very shortly if/when Telechips catch wind of the leak. If you're going to risk uploading them you'd be better using something like rapidshare or yousendit rather than here.

Given that these docs are currently available in the clear from Telechips' own website (albeit unintentionally by the looks of it) - does that mean were are technically 'allowed' to use them?

EDIT: sastraxi, if you wish I'll make you an initial patch to get you started. At this stage it's nowhere near ready for SVN - there's a lot of hackiness and issues to be worked out - but it'll give you a good solid starting point.

[paradox]

Actually, what's the legal situation here?
Many relevant files don't contain any legal disclaimer (e.g, the TCC7801 specs)
others state "No part of this publication may be reproduced, photocopied, stored on a retrieval system, or transmitted without the express written consent of Telechips, Inc. "

It should be legal to at least post the links, shouldn't it?

[saratoga]

If they're publicly distributing the documents with no license, then its generally assumed you are allowed to read them and produce code based on the information in them.  If they're distributing them with a license, then you must not do things prohibited by the license.  

[Llorean]

The important thing about copyright though, is "no license published means all copyright rights reserved." That means we cannot copy them into the wiki or redistribute them ourselves.

[shotofadds]

Ugh, my haste in playing with SVN to create a patch has resulted in a horribly broken build (ie. it builds but no worky!). I have backups but it's going to take some time to figure out what went wrong

EDIT: I restored the contents of firmware/* and it makes no difference. I still get a rockbox.iaudio that's 200 bytes larger than my old build and still does not work... very odd, will have to investigate later.