IRC logs for #openrisc Friday, 2013-10-25

--- Log opened Fri Oct 25 00:00:55 2013
stekernI have a weird problem with interrupts not working at all on my sockit02:51
poke53281And I have a problem in QEMU with exceptions directly following the activation of the MMU.03:14
poke53281QEMU seems to recursively execute a function until the stack explodes.03:14
stekernsounds like we both have interesting problems ;)03:15
poke53281And gdb and valgrind think everything is fine.03:15
poke53281until the segmentation fault.03:15
poke53281And both give me a big question mark.03:15
stekernI think I've managed to create a reduced testcase in simulations at least03:15
poke53281My solution will be to wait till the next qemu git master update. I am not sure if the OpenRISC target is the problem.03:16
stekernbah, my problem was down to a bug I already fixed, but I was building with an or1k-src that doesn't have that fix...03:38
poke53281And maybe I have found my problem. I misinterpreted the way QEMU reckognizes the current PC.04:27
PowermaniacWhat do you guys think about needing to go to one of the top universities to be able to get the job you want in the future? Do you think it really matters what unviersity you go to?04:50
hansfbaierPowermaniac: In the USA it seems to be important05:05
hansfbaierBut if you want to get the job you want, build your own company...05:06
hansfbaierThat would be another way05:06
Powermaniachansfbaier: Ahh okay05:20
Powermaniachansfbaier: Yeah it does seem rather important in America, here in Australia in is sort of more an option to go to university or not05:21
stekernin finland no-one seems to care about what university you went to05:29
poke53281The same is true in Germany.05:35
PowermaniacOh okay05:40
PowermaniacMaybe I should stop worrying about it all, see I was thinking about applying for MIT for the hell of it...Doubt I would get in though, haven't even sat the SAT or ACT tests05:41
PowermaniacWhereas I could probably get into the universities here in Australia pretty easily05:41
hansfbaierUSA = banana republic, it's below Nigeria in terms of income inequality05:43
hansfbaierin come equality I mean,05:43
hansfbaierSweden is #1. Hats off...05:43
PowermaniacYeah I've heard great things about Sweden mainly through Reddit05:44
stekernI'd say both extremes are bad...05:44
hansfbaierGermany is #8 or so...05:46
PowermaniacWait when you say #1 what do you mean, are you referring to income equality? or universities?05:47
hansfbaierstekern: Why do you implement synths in Hardware? Because you can, or are there other reasons.05:47
hansfbaierPowermaniac: Income equality05:47
PowermaniacAhh right05:47
stekernhansfbaier: why not?05:48
hansfbaierstekern: Well you can't use an FPGA as an LV2 plugin easily, for instance...05:48
hansfbaierstekern: The upside is you get killer latency05:49
stekernI don't see why you couldn't make that work05:49
stekernnot something I pursuing as a first step now though05:49
hansfbaierstekern: Plug the FPGA in via PCI(e) and write an LV2 plugin?05:49
stekernyes, or USB05:50
hansfbaierstekern: That would be very fine for things like convolution05:50
stekernbut latency, yes that's the main reason05:50
stekernand because I can05:50
hansfbaierstekern: USB latency is bad for audio.05:50
stekernI know, but a lot easier for a proof-of-concept05:50
hansfbaierstekern: But with a PCI sound card like the M-Audio 1010lt and a tuned Linux you get very good latency too, your ear won't notice...05:51
hansfbaierstekern: I get a couple of ms with my 1010lt, playing soft-synths feels really instant.05:53
stekernbut soft-synths are boring05:53
hansfbaierstekern: I think HW impl has real merit for computation intensive tasks like brute force convolution05:53
hansfbaierstekern: That's what I thought you'd say :)05:53
stekern...and I don't have a fancy PCI soundcard, nor a tuned linux05:55
stekernhansfbaier: but you can't claim that soft-synths have completely obsoleted hardware synths, there are still companies manufacturing hard synths06:15
hansfbaierstekern: no sure.06:16
hansfbaierstekern: What's interesting with HW synths is the interplay of analog and digital.06:18
stekernsure , but there are pure digital HW synths (most of the newer ones)06:19
stekernand analog hw design is boring (IMO)06:19
stekernbut the biggest problem with soft-synths is that you (kind of) need a dedicated computer for it06:23
stekernbecause, at least for me, the setup to get everything to work breaks pretty easily, so just "play a bit" when I happen to feel like it once a month doesn't really cut it for that06:27
hansfbaierstekern: not necessarily: eiYo3Eej06:27
hansfbaierI mean: uname -a06:27
hansfbaierLinux jack-desktop 3.2.0-41-lowlatency-pae #45-Ubuntu SMP PREEMPT Fri Apr 26 11:26:31 UTC 2013 i686 athlon i386 GNU/Linux06:27
stekernthe closest I've seen that "just works" is reason06:27
stekernbut that have the problem of being windows/mac only...06:28
stekernso I'd like to build something like that, but in an FPGA06:28
stekernwith a limited set of "hardware" of course06:29
stekerna drunm machine, a couple of synths, a sampler and a mixer06:30
stekernhansfbaier: with "dedicated", I meant, something you either take care of like a baby to work with sound work, or you don't touch06:32
stekernbecause, it took me 2 hours to just get jack and ardour working a couple of days ago since I hadn't used those for a while, that kind of kills all my inmspiration to start making any music06:33
hansfbaierstekern: Know what you mean ... :)06:36
olofk_Amen that06:39
olofk_And everytime I start out thinking: "I'm good with Linux, I've done this before, things must have gotten better since last time, I don't have any known problems with this computer"06:39
hansfbaierstekern: On which IRQ should I put the ones of the accelerometer and KEY2?06:49
hansfbaierI mean KEY1 in the schematics?06:49
hansfbaierin v2 it was 24/2506:49
hansfbaierBut with an `ifdef, but I don't think `ifdef is a good idea here, since they are onboard06:50
hansfbaierShould i just put them there without `ifdef? That's what I am intending to do.06:50
stekernyeah, sounds like a good idea06:51
hansfbaierThat accelerometer is a moody beast, why isn't it detected anymore, weird...08:02
hansfbaierstekern: That's super weird, I assigned the pin to 1, but I get the warning:  Warning (13410): Pin "accelerometer_cs_o" is stuck at GND08:22
hansfbaierWhy could that be?08:22
hansfbaierAAARRGGGHH! Again! Implicit wires....08:23
hansfbaierstekern: in OpenRISC / Linux are Interrupt lines active high?08:58
hansfbaiercool, finally the accelerometer works under linux09:09
-!- knz_ is now known as knz13:37
poelhi! I have a quick question about the openrisc support for linux14:06
poelin head.S, the kernel stack pointer is initialized to be at the exact top of the kernel stack14:07
poel(whereas in MIPS, for instance, the initial kernel stack ptr is shifted by a STACKFRAME+sizeof(pt_regs))14:07
poellater, in copy_thread, to create the first userspace task, there is a copy of regs: *userregs = *current_pt_regs()14:08
poelisn't that a possible security breach? since current_pt_regs() will refer to data that is not a pt_regs struct14:09
poelbut will contain random data created by the first stackframe (ie the stackframe of start_kernel)14:10
stekernpoel: interesting observation14:25
stekernJonas would probably be best fit to answer that, but he's not online, so I would suggest sending the question to too14:26
stekernpoel: but isn't the initial kernel pointer shifted in openrisc as well?
stekernwith a fixed 0x2000 value?14:42
stekernor am I misunderstanding things, first time I look at that part14:42
stekernah, now I understand, with the shift you are speaking about the '32 - PT_SIZE' here:
poelyes, in mips, the shift is 32-PT_SIZE which makes room for a stackframe+pt_regs14:49
poelin openrisc, the kernel stack pointer is initial at kernel_stack+0x2000 which is the full 8K of the kernel stack14:50
poelso the pointer will be at the topmost position of the kernel stack14:50
poelthus making no room for anything14:50
stekernyeah, I think I get it now14:50
poelI will try to find time to send an email asking about that on the ml14:51
_franck_any suggestion for a 8051 disassembler ?15:12
stekernI've got an assembler for dos laying around somewhere...15:17
_franck_I found dis51 looks like it works15:17
_franck_great I still have a version of IDA, this is much better :)15:30
rahfinal version15:51
rahseeing as people here have seen it already, I wonder if you would care to see the final version, now with added gradiosity! :-)15:52
rah(and possibly provide feedback :-)15:52
olofkAll right then. Pull request time!16:09
raholofk: please pull my about.txt into your brain and then provide constructive criticism of it16:11
olofkaha! I cherry-picked a patch16:14
olofkNow is there any traces of the repo I just fetched somewhere?16:15
olofkOops. _franck_ you forgot to add () around print, and I forgot to test that16:28
olofkDamn python2 users ;)16:28
olofkBaby waking up. Pull request time is over16:39
_franck_olofk: sorry. This python 2/3 support is very anoying17:55
poke53281stekern: Remember when I said that QEMU OpenRISC emulator compiles Frotz in 45 minutes while the i386 emulator needs only one or two minutes.17:56
poke53281The last four patches I wrote reduced 45 minutes to 5 minutes. And still with flags and tlb refill.17:56
stekernpoke53281: whoa! nice ;)18:27
stekernpython being broken between any realeas is very annoying18:29
stekernI did a thing at work with the xml parser that worked perfectly with 2.7, turned out it didn't work at all as expected with 2.6 or 3.318:30
stekernand today I tried to get pycurl to work with anything newer than 2.5 on windows... didn't have much luck18:31
poke53281Yes, my distribution has three different python versions because of this.18:40
poke53281And it gets very annoying.18:40
poke53281There is no way to know in the beginning which python version is correct until you execute it18:41
--- Log closed Sat Oct 26 00:00:56 2013

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