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by jahboater
Tue Aug 13, 2019 12:30 pm
Forum: C/C++
Topic: Ways to compile C/C++ code for pi
Replies: 10
Views: 3450

Re: Ways to compile C/C++ code for pi

An excellent C and C++ compiler is included, pre-installed, and ready to use. Create the usual little test program with any editor in a file called "hello.c" #include <stdio.h> int main( void ) { puts( "hello world!" ); } Compile it with: cc hello.c -o hello and finally, you can run the program as m...
by jahboater
Sun Aug 11, 2019 6:36 am
Forum: General discussion
Topic: Are there any disadvantages of using a microsd card above 32GB on the Pi 4?
Replies: 5
Views: 450

Re: Are there any disadvantages of using a microsd card above 32GB on the Pi 4?

Yes. Looking at this: https://www.amazon.co.uk/SanDisk-microSDXC-Memory-Adapter-Performance/dp/B073S8TQH6/ref=sr_1_4?keywords=sandisk+ultra+a1&qid=1565505152&s=gateway&sr=8-4 it seems that up to 128GB is cheap now, with a steep price rise per GB after that. Avoid NOOB's and you will be fine with the...
by jahboater
Sun Aug 11, 2019 6:29 am
Forum: General programming discussion
Topic: Liberation through Computer Literacy
Replies: 1177
Views: 56982

Re: Project Digital Apocalypse Not Now

Heater wrote:
Sun Aug 11, 2019 6:18 am

That does seem rather large.
Rust programs are statically linked are they not? so that known "safe" functions get used.
by jahboater
Sat Aug 10, 2019 8:13 pm
Forum: Bare metal, Assembly language
Topic: Announce: RusPiRo - a kernel the Rust way ;)
Replies: 51
Views: 4703

Re: Announce: RusPiRo - a kernel the Rust way ;)

1) Have read, fully understood and remember all details of the standards document for C/C++. Not C++ !!!!!!! C only. The C standard is far far smaller, easy to read, and actually quite helpful. Also, since many library functions are now included in the C standard, I usually refer to that rather tha...
by jahboater
Sat Aug 10, 2019 4:21 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

pica200 wrote:
Sat Aug 10, 2019 4:12 pm
I know the ground planes of the whole board will sink heat away but that's not enough to prevent throttling.
Its enough for shortish jobs (that's what thermal inertia means). Perhaps a couple of minutes.
by jahboater
Sat Aug 10, 2019 4:18 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

Especially if i'm gonna fire up gcc or similar ;) Don't worry about GCC! A 13,000 line compilation, with optimization, raises the temp of my Pi4 by 2C. Compiling GCC itself which is huge, using make -j5 (all four cores flat out for over 3 hours) did not reach throttling or even close. That's roughl...
by jahboater
Sat Aug 10, 2019 3:20 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

And the SoC may be fine up to 120°C but it causes stress to surrounding components aswell. And the solder balls under it which is the reason many cheap laptops with bad cooling fail early ;) You will find the Raspberry Pi is rather better engineered than that. In fact the SoC is deliberately therma...
by jahboater
Sat Aug 10, 2019 1:44 pm
Forum: Bare metal, Assembly language
Topic: Announce: RusPiRo - a kernel the Rust way ;)
Replies: 51
Views: 4703

Re: Announce: RusPiRo - a kernel the Rust way ;)

So now you can program in something C like. Soon you find that it's very tedious that your programs crash at random, have weird responses to odd input and are full of security vulnerabilities. I must say that I don't have all these problems. Nowadays I write important code to be strictly standard c...
by jahboater
Sat Aug 10, 2019 1:29 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

In the UK, all four CPU cores maxed out raised the temp from 54C at idle to 68C after about ten minutes. That's with NO fan! With a full desktop running and a few web browser tabs. Heavy use of NEON will make it hotter (see the cpuburn stress test). My Pi 4 runs at around 60C idle on the Raspbian d...
by jahboater
Sat Aug 10, 2019 1:28 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

bensimmo wrote:
Sat Aug 10, 2019 10:46 am
Which is the complete opposite to me where Chromium takes it up to 80c and throttles without a fan blowing gentle air over it. Many people see this, you're lucky.
Many people who put them in small plastic cases see this ....
by jahboater
Sat Aug 10, 2019 9:45 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

you will definitely reach throttling temps with that if you have any higher CPU load. Check for throttling with: vcgencmd get_throttled after running a typical workload. If it says 0x0 then you have had no thermal problems or power supply problems while running your task. The Pi4 like the older Pi3...
by jahboater
Sat Aug 10, 2019 8:32 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 97789

Re: Raspberry Pi 4 Thread - general discussion

chuUK wrote:
Sat Aug 10, 2019 8:23 am
Nor 8 shim fans which you HAVE to use if you want to use this as a working desktop
No you do not HAVE to.
My Pi4 which is my desktop and software development platform, runs very happily without one.
Never throttles under any load.
by jahboater
Fri Aug 09, 2019 10:13 pm
Forum: General discussion
Topic: Pi4 as Desktop computer
Replies: 245
Views: 20933

Re: Pi4 as Desktop computer

After wasting the whole afternoon trying I gave up. Doing such a thing is nearly but not quite yet supported by Rust. It takes hours to run the build anyway. A silly story perhaps. But my point is that software support is even more important than CPU speed and memory space when it comes to replacin...
by jahboater
Fri Aug 09, 2019 2:49 pm
Forum: Beginners
Topic: microSD card size?
Replies: 17
Views: 829

Re: microSD card size?

I would like to order a Raspberry Pi 4 model B+ with 4GB Ram but the largest microSD card is only 16GB. Could i buy a larger microSD card about 128GB or even 256GB? Who says the largest microSD card is only 16GB? I use 64GB or 128GB cards only, now that they are cheap (Sandisk A1) I know of no prob...
by jahboater
Fri Aug 09, 2019 1:54 pm
Forum: General discussion
Topic: Pi4 as Desktop computer
Replies: 245
Views: 20933

Re: Pi4 as Desktop computer

Pi4 as Desktop computer All my other computers are now boxed up and going into storage for our house move. I have kept out just one - my Pi4! So for an indeterminate period, the Pi4 will be my only computer .... I am using it now to post this. The compact "official" Raspberry Pi keyboard takes some...
by jahboater
Fri Aug 09, 2019 1:03 pm
Forum: Beginners
Topic: Can't install etcher.
Replies: 13
Views: 7329

Re: Can't install etcher.

dd if=$file of=$destDevice bs=65536 status=progress conv=fsync great script! Could I suggest 131072 for the block size (128k)? That is what the "cp" command uses. You can see what block sizes things use with, for example:- strace cp bigfile /dev/null You can of course just use cp instead of dd anyw...
by jahboater
Wed Aug 07, 2019 5:12 pm
Forum: OpenGLES
Topic: GLubyte and "+="
Replies: 9
Views: 1641

Re: GLubyte and "+="

PeterO wrote:
Wed Aug 07, 2019 4:19 pm
I'm sure this is all part of getting older as I'm sure I never used to worry about this sort of stuff if the code worked
Same here!
I suppose being retired now I have more time to be fussy and get everything right ...

Also compilers have much better diagnostics in recent years.
by jahboater
Wed Aug 07, 2019 4:43 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 20366

Re: Why moving to 64bit?

What I am actually against is the "64-bit only" brigade, particularly the software application developers who are forcing people on to 64-bit when they don't have to. I presume the software developers don't want to support two platforms. Therefore they have to choose one, and 64-bit is the future, ...
by jahboater
Wed Aug 07, 2019 1:19 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 20366

Re: Why moving to 64bit?

So it is simply a question of am I memory constrained by a 32bit system? If not then you don't need 64bits Why do people think that memory addressing is the only benefit of 64-bits? For a start ... 1) a modern instruction set that's designed for the newer high performance OOO cpu's like the Cortex-...
by jahboater
Wed Aug 07, 2019 12:55 pm
Forum: OpenGLES
Topic: GLubyte and "+="
Replies: 9
Views: 1641

Re: GLubyte and "+="

The integer promotion rule seems destined to cause lots of warnings with -Wconversion enabled :roll: You can blame ARM and other CPU's that cannot properly do arithmetic on anything smaller than a 32 bit "int". Intel CPU's have 16-bit and 8-bit registers that can do all types of arithmetic correctl...
by jahboater
Wed Aug 07, 2019 12:20 pm
Forum: OpenGLES
Topic: GLubyte and "+="
Replies: 9
Views: 1641

Re: GLubyte and "+="

Also, using "++step" instead of "step += 1" solves the problem too.

step += 1 is the same as step = step + 1. "step + 1" gets promoted to integer, and then that int is assigned to the smaller char type, which raises the warning. There is no separate expression when using ++, so no promotion.
by jahboater
Tue Aug 06, 2019 6:31 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 20366

Re: Why moving to 64bit?

You know, even though you guys are few, you have really managed to get a stable and good Debian based OS, Exactly. That's the problem! If Raspbian was not such a great, well supported, well produced OS, then I'd abandon it and use Ubuntu 64 or whatever the latest thing is. almost as stable and smoo...
by jahboater
Tue Aug 06, 2019 6:16 pm
Forum: General programming discussion
Topic: Liberation through Computer Literacy
Replies: 1177
Views: 56982

Re: Project Digital Apocalypse Not Now

Well, if your language does not allow you to read via an uninitialized pointer, if it does not allow the creation of null pointers, if it does not allow you to point at the wrong thing, if it does not allow you to share pointers for write operations, then there is no need for pointer checking at ru...
by jahboater
Tue Aug 06, 2019 2:24 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 20366

Re: Why moving to 64bit?

LTolledo wrote: ↑ Tue Aug 06, 2019 7:11 pm Will GPIO inputs be read faster with 64bit? will GPIO outputs switch faster on 64bit? No, because unless things have changed a lot, the GPIOs are 32 bit based and are in banks of 32 bits. Ok then.... I'll move to 64bit if the RPF supplied OS (and apps) goe...
by jahboater
Tue Aug 06, 2019 12:45 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 259
Views: 20366

Re: Why moving to 64bit?

Vanishingly few, for good and obvious reasons. But that's rather beside the point. The actual question is how many functions do I have which require local scalar variables to be preserved between function calls, and that's a: a *very* different question, and b: a much, much greater set. Perhaps tak...

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