DSL on Evo T20 thin client

Forum: DSL Tips and Tricks
Topic: DSL on Evo T20 thin client
started by: KarlMW

Posted by KarlMW on Sep. 26 2007,07:47

I'm running DSL on an HP/Compaq Evo T20. (rebadged Wyse 8235LE. Same core is in Compaq T30, too.)
These machines are commonly cheaply available on Ebay and suchlike. Performance is vaguely equivalent to a classic Pentium at 100MHz - not fabulous, but good enough to be useful.

I have documented the install process on my website at < http://mowson.org/karl/evo_t20/ > (including scripts to virtually automate patching the firmware). I'm happy to answer questions, if anyone needs help with the process.
(Note that my instructions are for the models that come with WinNT. There is another set of instructions for WinCE models, at < http://thunderlord.net.pl/evo/ > For WinXP models, there is no known install method yet)

Karl.

Posted by ^thehatsrule^ on Sep. 26 2007,15:24

Nice site. Though I don't have one of those machines, I took a quick glance at it and thought I'd comment on some of the oddities.

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Standard DSL boot includes probing for a AHA1542 SCSI interface. On the T20, when it tries to probe this module (looking for something to boot from), it freezes for just over a minute, before continuing normally. This can be fixed by modifying the DSL boot script (linuxrc).

If you have no use for scsi at all, you can easily pass the "noscsi" cheatcode in your bootloader.

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During boot, DSL bleats about "can't locate module block-major-2" - I presume that this is to do with the 'IDE' interface. It doesn't seem to cause any problems with DSL.

I think this is a leftover in the system where the actual binary was removed, but the references were not.

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I don't know how to access the internal flash after boot. There's something weird about it. This is not a problem though - grub can find the files and load them, and from then on we are relying on the external flashdrive. Later on I will document how to pack DSL into the initrd, so it can boot without any external flash (but that hasn't been done yet, as at 5 May 2007)

Try `fdisk -l`? You may be interested in the dsl-initrd version.

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If you set a non-zero timeout on the grub presetmenu, grub will sit and wait a very long time - it seems the "time" clock at that stage does not run at a normal speed (if at all - I don't know if it will ever time out).

That's probably due to the missing RTC.

EDIT: looks like you did find out about some of this already, guess just some things weren't updated

Posted by KarlMW on Sep. 27 2007,03:35

Quote (^thehatsrule^ @ Sep. 27 2007,03:24)

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If you have no use for scsi at all, you can easily pass the "noscsi" cheatcode in your bootloader.

Unfortunately, that also prevents USB boot, since linux sees USB as being SCSI. I need to look at my script for unpacking/editing initrd/linuxrc again, to make it easy to do these tweaks. I have edited the linuxrc before, but I want a cleaner way to do it, rather than manual unpacking/repacking.

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Try `fdisk -l`? You may be interested in the dsl-initrd version.

fdisk and blkid and /proc/partitions all show only my usb boot drive - they don't make any mention of the internal flash 'drive'

It seems that the 'IDE' controller is not fully setup - it appears not to have been assigned an interrupt, for a start. Using lspci -vv shows this for the IDE interface:
0000:00:12.2 IDE interface: Cyrix Corporation 5530 IDE [Kahlua] (prog-if 80 [Master])
Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 0
Region 4: I/O ports at fb00 [size=128]

Compared with this on one of my conventional linux boxes:
00:1f.1 IDE interface: Intel Corporation 82801DB (ICH4) IDE Controller (rev 01) (prog-if 8a [Master SecP PriP])
Subsystem: Dell Optiplex GX260
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 0
Interrupt: pin A routed to IRQ 18
Region 0: I/O ports at 01f0 [size=8]
Region 1: I/O ports at 03f4 [size=1]
Region 2: I/O ports at 0170 [size=8]
Region 3: I/O ports at 0374 [size=1]
Region 4: I/O ports at ffa0 [size=16]
Region 5: Memory at 40000000 (32-bit, non-prefetchable) [size=1K]

Note the lack of an interrupt assignment on the first listing, and possibly a lack of memory assignment too (I can't say I know how to interpret the listing fully). I am led to believe that MTD drivers may be able to access the internal flash, but I've not investigated it myself.

I have run DSL entirely from initrd before, and it is useful for some tasks. Unfortunately, without being able to read/write the internal flash, there is nowhere to store non-volatile runtime data, and a USB flash drive ends up being necessary for most things anyway. So, one may as well boot off the flash drive too :-)

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EDIT: looks like you did find out about some of this already, guess just some things weren't updated

I'm finding that even with a teensy little site such as mine, keeping everything up to date and consistent can take quite a lot of effort!

Thanks for your comments - I have made changes to my site, and made a note that I really should re-read all that I've written there and check that it still makes sense :-)

Posted by chaostic on Sep. 29 2007,18:10

Quote (^thehatsrule^ @ Sep. 26 2007,11:24)

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During boot, DSL bleats about "can't locate module block-major-2" - I presume that this is to do with the 'IDE' interface. It doesn't seem to cause any problems with DSL.

I think this is a leftover in the system where the actual binary was removed, but the references were not.

I tracked this down before. It is actually a floppy drive error, as in you have no floppy. Had the same error on my now flood damaged gateway solo 1150.