<whitequark>
However, for those of you not familiar with the Pi, it comes with very limited hardware resources (including 512 MB of memory) which can be easily consumed by a [while] loop [in Bash] like the one I'm using.
porchao has joined #qi-hardware
<whitequark>
by the way, an acquaintance of mine recently suggested another reason broadcom could be selling pis at a tiny margin
<whitequark>
apparently if you have a few thousands of unliquidated chips (or early revisions, or slightly broken ones), it is somehow problematic to just dump them in a landfill
<lekernel>
didn't they sell millions?
<whitequark>
"a few thousands" was a figure of speech
<whitequark>
millions. well, not sure
<ysionneau>
"can't sell those to real customers, so let's make a false open source design to at least squizz some internet buzz out of it" ?
<viric>
but pis work, don't they?
<ysionneau>
maybe they don't work at 85°C :)
<viric>
ah
<ysionneau>
or -40
<ysionneau>
or some part of the chip does not work
<ysionneau>
maybe it's parts on the sides of the waffers
<viric>
btw, anyone knows where to find a reasonably priced infrared camera+lamp, for night seeing? usb would be fine.
<viric>
ysionneau: I've one and it always worked fine, for the limited work I gave.
<whitequark>
ysionneau: yeah
<whitequark>
the reason he said that: you know the ODROID thingy?
<whitequark>
hardkernel.com etc
<viric>
a friend reported many fails for odroid
<whitequark>
he worked quite a bit with the devices and it turns out that they indeed ship failed/early batches
<whitequark>
yeah
<viric>
for his odroid.
<ysionneau>
viric: indeed, but you cannot notice that some IP core not routed to the Rpi PCB (so feature not present on the Rpi) is not working
<ysionneau>
because you simply cannot test it
<ysionneau>
and you don't care
<viric>
ysionneau: then it's fine for me. It's the same for two-core, three-core computers
<whitequark>
for programmers who have the true C spirit: "I don't care if it works if it is fast!" :p
<viric>
yes, on that line :) but with hardware.
<viric>
Performance boost!
FDCX has quit [Remote host closed the connection]
FDCX has joined #qi-hardware
unclouded has quit [Ping timeout: 245 seconds]
rz2k has quit [Ping timeout: 240 seconds]
jekhor has quit [Ping timeout: 264 seconds]
LunaVorax has joined #qi-hardware
Fummy has joined #qi-hardware
LunaVorax has quit [Ping timeout: 252 seconds]
rz2k has joined #qi-hardware
Fummy has quit [Ping timeout: 248 seconds]
Fummy has joined #qi-hardware
wej_ has joined #qi-hardware
wej has quit [Ping timeout: 248 seconds]
<wpwrak>
prolog/lisp: i don't care of it works, as long as the experience is good :)
<whitequark>
missing the point ;)
<whitequark>
I only recently talked with a self-described C programmer
<whitequark>
he had a program which only worked correctly when compiled with -O2 (implying he has really bad UB somewhere)
<whitequark>
so what he did, could you guess?
<whitequark>
added "compile with -O2" to README
<whitequark>
and (in my eyes) this attitude is too prevalent and too harmful. I don't care about minor issues like manual MM vs GC :p
<wpwrak>
UB = ?
<whitequark>
undefined behavior
<whitequark>
overall, that would mean that his program works "correctly" (even if it does) purely by accident, and changing so much as a minor version of GCC would suffice to break it
<whitequark>
but I'm pretty sure you already know it
<wpwrak>
seems that he should try, in this order, -Wall, and then valgrind :)
<wpwrak>
no everything can be caught this way, but a lot
<whitequark>
wpwrak: oh, sure, or -fsanitize=undefined
<whitequark>
but the problem is that he doesn't want
<whitequark>
"yeah, gotta build it with -O2, whatever, I don't care as long as it works"
<whitequark>
and he defended that even after an explanation of what UB actually is
* whitequark
sighs
emeb has joined #qi-hardware
<wpwrak>
does he work on embedded controllers for battery management in the boeing dreamliner ? :)
<whitequark>
no, on cloud storage stuff (I think), and plans to work on OS kernels if I'm not confused
<larsc>
well as long as it is the Windows kernel I'm fine with that
<whitequark>
lol
<whitequark>
windows kernel is actually not that bad
<whitequark>
something something working async I/O :p
<larsc>
only speeding up the inevitable
apelete has quit [Ping timeout: 276 seconds]
Fummy has quit [Ping timeout: 252 seconds]
LunaVorax has joined #qi-hardware
pcercuei has joined #qi-hardware
_ffio_ has joined #qi-hardware
ffio_ has quit [Ping timeout: 240 seconds]
pcercuei has quit [Ping timeout: 252 seconds]
pcercuei has joined #qi-hardware
<whitequark>
btw wpwrak
<whitequark>
have you seen Cyclone?
<whitequark>
that actually seems to have some slim chances you'd even try writing code in it :)
<wpwrak>
do you think i obsess about pointers ? :)
<wpwrak>
almost anything that i occasionally do wrong with pointers is easily found by valgrind.
jekhor has joined #qi-hardware
rz2k has quit []
<viric>
wpwrak: you should not use heap memory. :)
<wpwrak>
you prefer arrays ?
jekhor has quit [Read error: Operation timed out]
<larsc>
one big global state struct
<viric>
for example :)
<viric>
stack is overrated too.
<viric>
I should back up luks headers...
<viric>
larsc: is there any way I can see what my 'kworkers' do?
<viric>
kwoerker/0:1H for example, does it indicate anything?
<larsc>
depends on the definition of 'do'
<larsc>
;)
<viric>
hehe
<viric>
cat /proc/PID/stack?
<larsc>
no what do you mean by do
<larsc>
?
<larsc>
do you want to know what code they execute
<larsc>
or when they execute
<viric>
I see them on 'top'
<larsc>
yes
<viric>
does each PID have a specific task? or they pick tasks from queues?
<larsc>
depends
<larsc>
e.g. kworker:mmcqueue
<larsc>
will do mmc card related stuff
<larsc>
but there are also generic workers which just queue up 'random' things
<viric>
# cat /proc/4567/stack
<viric>
[<c002acb4>] msleep+0x24/0x30
<viric>
[<c040e0e0>] mmc_power_up+0xd0/0xd4
<viric>
[<c040ef8c>] mmc_rescan+0x29c/0x3a4
<viric>
^ this one appears on top often
<viric>
named "kworker/u:1"
<larsc>
that's a generic one though
<viric>
- I don't have any mmc card put in the slot.
<larsc>
in the kernel there are so called workqueues
<larsc>
a driver can create a custom workqueue
<larsc>
but there are also a couple of generic workqueues
<larsc>
which are usually used
<viric>
ok
<larsc>
unless your queue needs like a special priority or something
<larsc>
the generic queues are basicall first come first served
<viric>
what is that language of "/u:1" ?
<larsc>
I don't know, but should be easy to find that out
<viric>
and u = without cpu assigned. pool->id vs id, I don't know.
<viric>
this sheevaplug crypto device isn't performing as I'd expect
<larsc>
probably not caused by the worker tasks though
<viric>
oh, Kconfig reads: "Currently the driver supports AES in ECB and CBC mode without DMA."
lekernel has quit [Quit: Leaving]
emeb has quit [Ping timeout: 248 seconds]
LunaVorax has quit [Read error: Connection reset by peer]
viric has quit [Ping timeout: 240 seconds]
viric has joined #qi-hardware
<Luke-Jr>
can anyone recommend a JTAG cable with best free software support?
<viric>
check openocd.
<viric>
maybe they tell about jtag adapters
<larsc>
I'm not sure if I can recommend a FTDI, but usually it works
<viric>
the sheevaplug has a ftdi jtag thing in it, and it's the only one I've used.
<Luke-Jr>
hmm
<Luke-Jr>
I actually wrote a FT232R-based JTAG bitbanging interface.. maybe I can use that somehow
<Luke-Jr>
hmm, one of these is open hardware
jekhor has joined #qi-hardware
LunaVorax has joined #qi-hardware
unclouded has joined #qi-hardware
pcercuei has quit [Ping timeout: 246 seconds]
<wpwrak>
the Amontec JTAGkey works quite well. ftdi-based.
<wpwrak>
similarly, the famous openmoko debug board is quite nice. also brings out serial and has a built-in usb hub. there, you even get the schematics.
<larsc>
if you have enough spare flex cables
<wpwrak>
drawback of the openmoko board: you need to add the headers for the cable yourself.
<Luke-Jr>
hmm, the nanonote thing leaves most pins unconnected?
<Luke-Jr>
I'm talking to an AVR32, but I'd like to have something I can use for any purpose
<Luke-Jr>
if I can justify buying a Nanonote, that'd be neat ;)
<Luke-Jr>
I do have some GTA0x here somewhere
<wpwrak>
the nanonote critter connects everything a xilinx fpga needs. not all devices are happy with so little, though. but then you still have two spare pins (in the xilinx layout). i could have added a serial console on them :)
<wpwrak>
the ubb-jtag wasn't really meant to be a "real" solution. more a proof of concept. but of course, if you need only low speed, it works just fine. and you could always make an optimized driver that would then be MUCH faster than the /sys/class/gpio-based one that proof of concept uses.
<wpwrak>
i think sharism.cc if dead for good. but try pulster.eu
<Luke-Jr>
any idea how many volts the openmoko debug board uses for JTAG? or can it autodetect?
<Luke-Jr>
…assuming I can still buy one of these somewhere :/
apelete has joined #qi-hardware
wej_ has quit [Ping timeout: 245 seconds]
jekhor has quit [Ping timeout: 240 seconds]
<wpwrak>
the openmoko board is 3.3 V, no autodetect
<Luke-Jr>
also seems I'd have to pay $50 + import customs to get it "gratis" from some german store
<Luke-Jr>
:/
<Luke-Jr>
wish I could just build one of the open hardware ones, but apparently chips will burn out if I try to solder them normally? :?
viric has quit [Ping timeout: 240 seconds]
<wpwrak>
oh, interesting twist :) maybe mail him and ask if he sells them "normally" as well. and yes, customs always want their share :)
<wpwrak>
and no, if you solder chips normally, they don't burn out :)
viric has joined #qi-hardware
_ffio_ has quit [Ping timeout: 240 seconds]
_ffio_ has joined #qi-hardware
kuribas has quit [Quit: ERC Version 5.3 (IRC client for Emacs)]
nutt has joined #qi-hardware
<nutt>
hey anyone, I just replaced a touchpad assembly for an hp pavilion dv6 laptop and had it up and running after replacing it for a couple hours. Then I rebooted to install updates and now it can't boot
<nutt>
I tried the recovery disc and it can't find an os
<nutt>
any ideas?
viric has quit [Ping timeout: 240 seconds]
ysionneau has quit [Ping timeout: 240 seconds]
apelete has quit [Ping timeout: 260 seconds]
viric has joined #qi-hardware
ysionneau has joined #qi-hardware
Jurting_pc2 has quit [Read error: Connection reset by peer]
<Luke-Jr>
wpwrak: well, the $50 is shipping to USA and bank wire fee - so non-gratis would just be additional on top of it :/
<Luke-Jr>
wpwrak: is the solder thing something that has changed over the years? my father apparently had to stop using chips entirely when they stopped doing sockets, because of this; maybe at some point chips began to be more heat-tolerant?
<roh>
more? nah
<roh>
the only reason for solderchanges recent years was ROHS... basically a systematic ban on some metals like lead where possible
<roh>
but thats industry-wide.. all consumer stuff. there are extemtions for some telco and network equipment also.
emeb has joined #qi-hardware
<roh>
the moko debugboard is a quite basic ftdi2232 application. you can also solder one yourself. just keep all leads short and dont forget the proper caps ;)
<roh>
amontec also has similar boards (also in simplicity)
<roh>
seems doable even for beginners. simple one-sided board. if somebody with a clue helps a bit it can be even done with kitchen-table etching
<Luke-Jr>
roh: not sure the interface is open (closed firmware) :/
<Luke-Jr>
so I may not have any way to use it
<Luke-Jr>
"To test if the board is working you’ll have to give 5V to the board by connecting a 10pin cable to one of the headers(JTAG or AVR ISP). Make sure you use a regulated 5V source or you might damage your USB port."
<Luke-Jr>
huh? why not just use the USB power? :/
<roh>
or just buy a jtag-ice on ebay.. there is open sw on the pc afaik. the firmware is flashed onto the device
wej has quit [Ping timeout: 248 seconds]
<Luke-Jr>
hmm, ebay
<roh>
i just heard from my 'off' that i should just use the jtag-ice in that box... hrrr.. i like this hackerspace
<roh>
just no pic programmer around.
<Luke-Jr>
?
<roh>
i just soldered a GPIB interface and need to flash the fw