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by jahboater
Sun Oct 08, 2017 1:39 pm
Forum: General discussion
Topic: SD card permanently write protected???
Replies: 20
Views: 9502

Re: SD card permanently write protected???

Heater wrote:
Sun Oct 08, 2017 12:15 pm
One could speculate that it is connected to issues with marginal power supplies that the Pi is particularly sensitive to.
That sounds very likely.

Also the additional demands of a full OS, compared to use as a data card in camera or a phone.

I have found these cards to be very reliable.
by jahboater
Sun Oct 08, 2017 12:00 pm
Forum: General discussion
Topic: SD card permanently write protected???
Replies: 20
Views: 9502

Re: SD card permanently write protected???

I thought this was because the firmware in the card itself had decided the card was faulty and sensibly disabled writes to help preserve any remaining user data.
by jahboater
Sun Oct 08, 2017 11:43 am
Forum: C/C++
Topic: Problem with longjmp on Pi Zero W
Replies: 16
Views: 4030

Re: Problem with longjmp on Pi Zero W

Just a very very long shot, do you have "-Wclobbered" enabled?

-Wclobbered
Warn for variables that might be changed by "longjmp" or "vfork". This warning is also enabled by -Wextra.
by jahboater
Sun Oct 08, 2017 8:34 am
Forum: Bare metal, Assembly language
Topic: Anyone can compile the LdB sample on linux?
Replies: 5
Views: 2143

Re: Anyone can compile the LdB sample on linux?

On that latest Raspbian (stretch) the default installed compiler is GCC 6.3.

and the default C language standard for 6.3 is now -std=gnu11 (C11).
by jahboater
Sun Oct 08, 2017 7:55 am
Forum: Beginners
Topic: 64 bit distro
Replies: 4
Views: 1788

Re: 64 bit distro

The answer is more or less no. There is no 64-bit version of Raspbian for the Pi. Raspbian is the "official" Linux distro for the Pi and is the best. There are a number of other 64-bit distro's available which may suit depending on what you want to do, or there are other similar Cortex-A5...
by jahboater
Thu Oct 05, 2017 7:40 pm
Forum: Python
Topic: Python IDE
Replies: 10
Views: 5400

Re: Python IDE

And for the long term solution, start using Python 3 :)
by jahboater
Thu Oct 05, 2017 5:30 pm
Forum: Troubleshooting
Topic: ssh password-less login with rsa not working
Replies: 10
Views: 3502

Re: ssh password-less login with rsa not working

+1 It is not hard.

Please just follow instructions posted by Rattus above

ssh-keygen -t rsa
ssh-copy-id user@host

and it always works.
I suggest starting with a fresh Raspbian.
by jahboater
Thu Oct 05, 2017 5:22 pm
Forum: Raspberry Pi OS
Topic: Latest Raspbian (Lite) download buggy?
Replies: 2
Views: 752

Re: Latest Raspbian (Lite) download buggy?

When enabling via raspi-config, tried to install around 120 different packages and appears to fail on at least 5. Had to manually get VNC server to start both initially and at boot. Download is dated 2017-09-07. Have not yet tried the full Raspbian with PIXEL with same date yet. I would try the ful...
by jahboater
Thu Oct 05, 2017 5:03 pm
Forum: Other programming languages
Topic: golang?
Replies: 22
Views: 44275

Re: golang?

Where performance may be an issue is with the garbage collector built into Go. But if you are using malloc/free in C or new/delete in C++ you may have similar hiccups. I think the difference is that malloc/free are called when the programmer wants them to be called, and commonly for a single item o...
by jahboater
Wed Oct 04, 2017 3:21 pm
Forum: Off topic discussion
Topic: is software harder than hardware? :)
Replies: 43
Views: 13900

Re: is software harder than hardware? :)

A very broad generalization, but ... Mechanical projects are limited by the number of moving parts (a few hundred perhaps). Electronics is limited by the number of transistors or gates that can be put on a chip (a billion or so). Software growth is limited only by the ability of humans to manage its...
by jahboater
Wed Oct 04, 2017 12:04 pm
Forum: Advanced users
Topic: System Call Linux to Raspi
Replies: 20
Views: 3884

Re: System Call Linux to Raspi

but when it comes to saying "get the tarball" that part i dont understand. I think if you are doing CS at uni, you need to get used to finding things out for yourself. You wont get far in the industry if you don't. A few seconds with google tell's you what a tarball is, and a few seconds ...
by jahboater
Wed Oct 04, 2017 11:27 am
Forum: Advanced users
Topic: System Call Linux to Raspi
Replies: 20
Views: 3884

Re: System Call Linux to Raspi

ghans wrote:
Wed Oct 04, 2017 9:52 am
Somebody must've thought this is too boring and said : Now , do it on a Raspberry Pi !
Actually the Pi is probably a good choice for this sort of risky experimentation. On a PC I would use a VM. In neither case is it a big deal if you end up with an unbootable machine!
by jahboater
Tue Oct 03, 2017 7:26 pm
Forum: Advanced users
Topic: System Call Linux to Raspi
Replies: 20
Views: 3884

Re: System Call Linux to Raspi

A quick google showed this tutorial amongst others:-

https://brennan.io/2016/11/14/kernel-dev-ep3/
by jahboater
Tue Oct 03, 2017 4:47 pm
Forum: General programming discussion
Topic: Sync Time from Internet
Replies: 20
Views: 89737

Re: Sync Time from Internet

DougieLawson wrote:
Tue Oct 03, 2017 6:18 am
Start by running timedatectl with no parameters.
Thats a handy command I didn't know about! Thanks.

I've added it to the .bashrc on my Pi Zero W digital clock so I can see all is well when I log in.
by jahboater
Tue Oct 03, 2017 4:21 pm
Forum: Advanced users
Topic: System Call Linux to Raspi
Replies: 20
Views: 3884

Re: System Call Linux to Raspi

Is this a new system call you want to add to the kernel - so you can call it in the usual way with "svc #0" ? Presumably as an academic exercise? There is some misunderstanding on these forums what a system call is. I keep seeing system( "ls -l" ) being referred to as a system ca...
by jahboater
Mon Oct 02, 2017 4:53 pm
Forum: Troubleshooting
Topic: exec format error jar file
Replies: 11
Views: 2936

Re: exec format error jar file

knute wrote:
Mon Oct 02, 2017 1:49 pm
I don't know if there is a 64 bit OS for the Pi
There are various 64-bit OS's for the Pi, but I doubt they will help.
by jahboater
Mon Oct 02, 2017 12:16 pm
Forum: General discussion
Topic: If you built a fully loaded Raspbian
Replies: 18
Views: 3760

Re: If you built a fully loaded Raspbian

mikerr wrote:
Mon Oct 02, 2017 11:28 am
Actually no - Etcher supports writing direct from the zip file - so just download the zip, and point Etcher at it. Job Done.
Yes I know. Its good, and it avoids using the unreliable Windows unzip.
by jahboater
Mon Oct 02, 2017 9:50 am
Forum: General discussion
Topic: If you built a fully loaded Raspbian
Replies: 18
Views: 3760

Re: If you built a fully loaded Raspbian

You only have to look at what we do here all the time - writing a Raspbian Image. Full Raspbian is over 4GB and needs the 64-bit version of unzip. Despite the 64-bit version being around for over 10 years, the WIndows unzip's often fail, and people have to download and install a third party product ...
by jahboater
Mon Oct 02, 2017 8:56 am
Forum: Beginners
Topic: All these names..... Jessie v Strech.
Replies: 9
Views: 1687

Re: All these names..... Jessie v Strech.

But as I had mentioned how to read/write RPI images (implied from a RPI) when you mentioned that, I took it as read that it was for the ARM. You can write the Raspbian image with a Windows PC, or a Mac or any Linux machine. The Raspberry Pi is a Linux machine. If you want to flash your card using a...
by jahboater
Mon Oct 02, 2017 8:38 am
Forum: General discussion
Topic: If you built a fully loaded Raspbian
Replies: 18
Views: 3760

Re: If you built a fully loaded Raspbian

...it takes a week to do things in Linux that can be done in seconds on a Windows system. And vice-versa. For example: It took most of working day to get our office printer to print from my Linux box. My Windows using colleague spent a whole working day trying to do it from Windows. He gave up! It'...
by jahboater
Mon Oct 02, 2017 8:08 am
Forum: General discussion
Topic: ssh to current session
Replies: 11
Views: 3327

Re: ssh to current session

RealVNC is included within Raspbian, it doesn't need to be installed. But yes, you do need the client executable on your PC. VNC does need to be enabled in raspi-config Edit: I see the OP doesn't want to use VNC for some reason. Don't you need to be on a Linux console to use the frame buffer directly?
by jahboater
Mon Oct 02, 2017 8:03 am
Forum: C/C++
Topic: makefile WiringPi
Replies: 4
Views: 4253

Re: makefile WiringPi

Did you follow Gordon's instructions exactly? to the letter?
Perhaps double check it, and post your makefile.
by jahboater
Sun Oct 01, 2017 7:58 am
Forum: General programming discussion
Topic: Development Environment
Replies: 5
Views: 2886

Re: Development Environment

I've built a pretty substantial C++ project this way, about 8000 lines of code so far. The biggest thing I routinely build on the Pi is the compiler itself which was around 17,000,000 lines of code last time I looked. Takes about 6 hours on a Pi3 and about 2 days on a Pi Zero! But it does work - pr...
by jahboater
Sun Oct 01, 2017 7:48 am
Forum: General discussion
Topic: Seven Segement Display
Replies: 4
Views: 788

Re: Seven Segement Display

by jahboater
Sun Oct 01, 2017 7:41 am
Forum: General discussion
Topic: could not find the path where Red Node is installed
Replies: 2
Views: 563

Re: could not find the path where Red Node is installed

You could try the "which" command.

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