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by DavidS
Wed Jun 26, 2019 3:18 pm
Forum: Bare metal, Assembly language
Topic: Raspberry Pi 4
Replies: 17
Views: 615

Re: Raspberry Pi 4

I am looking forward to the peripheral documentation as well. Even if many things are the same, there is going to be some difference in the base address for the peripheral registers, just to allow for the added RAM (and also curious how they map the peripheral registers into a 4GB config running in ...
by DavidS
Wed Jun 26, 2019 1:34 pm
Forum: RISCOS
Topic: New official keyboard - RISCOS
Replies: 6
Views: 1676

Re: New official keyboard

Why does the new keyboard fail to give the correct upper case characters (SHIFT) ? I've discovered I can correct this behaviour with (CTRL-SHIFT-NUMLOCK). But why should I have to do this on every boot? Is there some way of getting it to behave normally? I'm mainly using RISC OS by the way. Charles...
by DavidS
Wed Jun 26, 2019 1:30 pm
Forum: RISCOS
Topic: RISC OS and Hyperpixel Screen
Replies: 4
Views: 6647

Re: RISC OS and Hyperpixel Screen

Thanks handsomegenius. Yes, wireless internet connection would be good if possible, otherwise I could connect up when in the office/home. Not having "distractions" like the internet could be helpful when getting work done! When I used a Psion Series 3c (and later a Series 5) without internet connec...
by DavidS
Tue Jun 25, 2019 10:47 pm
Forum: Other
Topic: Windows 10 ARM64 (Dekstop, not IOT)
Replies: 50
Views: 9654

Re: Windows 10 ARM64 (Dekstop, not IOT)

I will always point out that ReactOS is quite usable, it just has not got a working ARM native build yet, though the work is being done. So it makes more sense to help the ReactOS project get a working ARM native version with support for running on the RPi than to waste time attempting to get Win 1...
by DavidS
Tue Jun 25, 2019 10:27 pm
Forum: General discussion
Topic: LINUX to WIN 10 Remote Desktop Connectivity
Replies: 5
Views: 123

Re: LINUX to WIN 10 Remote Desktop Connectivity

As with any computer use VNC. VNC is the "Remote Desktop" protocol that is not dependent on any proprietary system.

There are many VNC Clients for Windows, and most Linux distros come with a VNC Server.
by DavidS
Tue Jun 25, 2019 8:28 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 425
Views: 21375

Re: Raspberry Pi 4 Thread - general discussion

While it will likely be years before I have the money for a 4K monitor, I am still looking forward to getting my hands on a 2GB RPi 4B. As soon as ROOL anounces a beta release for the RPi 4B I will be ordering one (need an OS to go with the HW). This should be truly impressive to test the new SMP su...
by DavidS
Tue Jun 25, 2019 11:20 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 425
Views: 21375

Re: Raspberry Pi 4 Thread - general discussion

@jamesh I dont know if this has been asked and answered in this thread (or other threads) before but let me ask it again... is the device limit for USB drives (before it was max 6 drives only, due to hardware limitations) been upgraded on the RPi4B? if so what is the new limit? No such limit on any...
by DavidS
Tue Jun 25, 2019 11:15 am
Forum: General discussion
Topic: Can Raspberry Pi 4 play HEVC 1080p videos?
Replies: 5
Views: 271

Re: Can Raspberry Pi 4 play HEVC 1080p videos?

Why? Even the RPi 1 B can play 1080 video in more efficient formats, and that with software rendering on the ARM side. Why use a known processing intensive video format, that serves no more purpose than the more usable formats?
by DavidS
Tue Jun 25, 2019 4:32 am
Forum: General discussion
Topic: The RPi4 makes no sense to me. Fight me!
Replies: 30
Views: 1466

Re: The RPi4 makes no sense to me. Fight me!

I have always considered the Raspberry Pi as a platform for embedded systems, with using it as a generic computer being only a fringe application. Enter the RPi4. Dual 4K monitors? USB3? Does someone who can afford the dual 4K monitors (not to mention the adapters :) ), really need to save a couple...
by DavidS
Tue Jun 25, 2019 3:23 am
Forum: General discussion
Topic: (pi4) so how fast is 'entry level pc performance'
Replies: 11
Views: 675

Re: (pi4) so how fast is 'entry level pc performance'

Entry level PC is a currently marketed Personal Computer that meets the needs of the target user, and is the lowest end system to meet those needs. So if the user needs something to do some 16 color 320x200 graphics at 10FPS and that is the most intense application for that user, then one of the man...
by DavidS
Tue Jun 25, 2019 3:16 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 425
Views: 21375

Re: Raspberry Pi 4 Thread - general discussion

plugwash wrote:
Tue Jun 25, 2019 3:11 am
umm the openscad situation doesn't seem to have changed between stretch and buster, it's not available for armel/armhf because debian builds qt on armel/armhf against opengl es :/
Ok, and it takes a lot of work to build OpenSCAD. Well at least there are more alternatives now.
by DavidS
Tue Jun 25, 2019 3:14 am
Forum: General discussion
Topic: Is the new Raspberry Pi 4 vulnerable to Meltdown and Spectre attacks?
Replies: 13
Views: 993

Re: Is the new Raspberry Pi 4 vulnerable to Meltdown and Spectre attacks?

Put another way, it is normal for most systems to allow read access between protected contexts. There should be no data anywhere on your system that if read from an unknown context could be a vulnerability in any way. So no passwords in raw text or in a form that is easy to decrypt (and ideally only...
by DavidS
Tue Jun 25, 2019 3:07 am
Forum: General discussion
Topic: Is the new Raspberry Pi 4 vulnerable to Meltdown and Spectre attacks?
Replies: 13
Views: 993

Re: Is the new Raspberry Pi 4 vulnerable to Meltdown and Spectre attacks?

I do not understand why it would matter if it is vulnerable to a Spectre attack, that is just a way of getting at information that is not accessible from normal modes of operation. So what information would you have on an internet connected machine that would matter in such a way. I guess it is tech...
by DavidS
Tue Jun 25, 2019 2:40 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 425
Views: 21375

Re: Raspberry Pi 4 Thread - general discussion

Looking interesting. It will be great to play with a 4GB RAM RPi with faster RAM and a newer VC GPU. Finally maybe an ARM fast enough to use Linux as the main OS on :). Once I can afford one I will be placing an order (for a 2GB version). The OS upgrade also has my attention, going to an OS base tha...
by DavidS
Thu May 23, 2019 9:35 pm
Forum: Bare metal, Assembly language
Topic: A little Progress on my little OS Project:
Replies: 23
Views: 1456

Re: A little Progress on my little OS Project:

Mysterious blessings: Maybe it is just a random blessing that I am having trouble uploading to GitHub today. I just tryed the updated code on the ARMv8 based RPi 3B and it failed do to not recognizing the SETEND instruction. I am not sure why this would not work in AARCH32 on the ARMv8 used in the R...
by DavidS
Thu May 23, 2019 2:49 pm
Forum: Bare metal, Assembly language
Topic: A little Progress on my little OS Project:
Replies: 23
Views: 1456

Re: A little Progress on my little OS Project:

Another Update:
I am able to edit the readme.md and wiki pages now on github. Still having trouble uploading will let it be known when I manage to get that bit going.
by DavidS
Thu May 23, 2019 1:58 pm
Forum: Bare metal, Assembly language
Topic: A little Progress on my little OS Project:
Replies: 23
Views: 1456

Re: A little Progress on my little OS Project:

Sounds awesome. What's the link to your repository on github? The link is: https://github.com/ARMDavid/ArmTOS NOTE: As I have not been able to update that, the info is wrong. I am not using a CPU emulator at all (yet), everything is ARMv7 native and the OS is a new TOS API compatible OS (Big Endian...
by DavidS
Thu May 23, 2019 12:45 pm
Forum: Bare metal, Assembly language
Topic: A little Progress on my little OS Project:
Replies: 23
Views: 1456

Re: A little Progress on my little OS Project:

I like the simpler OpenVG, mainly because I don't understand OpenGL yet ;) Getting the GUI working convinced me I need the rest of an real OS. No one has told me they own Punk OS yet ;) Sounds like you are much further along than most of us. I've been distracted by seeing if I can have AI/NN built ...
by DavidS
Thu May 23, 2019 3:00 am
Forum: Bare metal, Assembly language
Topic: A little Progress on my little OS Project:
Replies: 23
Views: 1456

A little Progress on my little OS Project:

I have managed to get far enough to do some of the development self hosted. The spec largely is modeled after what is already posted at github, though I can not seem to make any updates or uploads there, sorry about that issue. I will be updating the github wiki for this project as soon as I can, an...
by DavidS
Tue May 21, 2019 4:58 am
Forum: Bare metal, Assembly language
Topic: Puzzled, Mem speed?
Replies: 31
Views: 2589

Re: Puzzled, Mem speed?

It is interesting how people have pointed out issues with using a single instruction pair for memcopy . I think we all know these. The test case example (and the kind of thing that would be done this way), is for a memset operation using a single STMIA instruction in the inner loop (no load operatio...
by DavidS
Tue Mar 19, 2019 10:49 am
Forum: Other projects
Topic: Using an RPi to reduce Power Usage, Off Grid.
Replies: 8
Views: 622

Re: Using an RPi to reduce Power Usage, Off Grid.

If anyone has any suggestions on things that can be done to improve on what I am doing, please give them. As I understand it, an original B+ will draw about half the current of an original B, so might be worth moving to one of those. Valid point. Unfortunately I only have two B+ boards at the momen...
by DavidS
Tue Mar 19, 2019 10:43 am
Forum: Bare metal, Assembly language
Topic: Puzzled, Mem speed?
Replies: 31
Views: 2589

Re: Puzzled, Mem speed?

The reason being that these units could be put to other uses while the memcopy is being completed by DMA, and I do not know of many personal computers that are without DMA. I don't think moving stuff between memory and registers with LDM or LDP or LDR can use DMA ? Or is this an ARM thing I don't k...
by DavidS
Tue Mar 19, 2019 10:35 am
Forum: Other projects
Topic: Using an RPi to reduce Power Usage, Off Grid.
Replies: 8
Views: 622

Using an RPi to reduce Power Usage, Off Grid.

It took me some time to get down to 2.0KW/h per day power consumption using traditional methods of usage timing, and careful selection of devices that consume power. Now I am working on using an old Raspberry Pi Model B (original 2012 model with full sized SD-Card) with a serial attached Arduino Meg...
by DavidS
Tue Mar 19, 2019 10:05 am
Forum: Bare metal, Assembly language
Topic: Puzzled, Mem speed?
Replies: 31
Views: 2589

Re: Puzzled, Mem speed?

Hi, I am using the ARM STM instruction in a loop that I have verified to be the fastest possible, storing 4 registers per store (any more or less slows us down). Only one store per iteration of the loop (any more slows us down). This seems odd. Here I've linked more memcpy implementations, but all ...
by DavidS
Sun Mar 17, 2019 4:06 pm
Forum: Bare metal, Assembly language
Topic: How to use gpio clock
Replies: 4
Views: 847

Re: How to use gpio clock

That depends on how you are setting up the PWM registers. Could we have your assembler for the PWM registers? .section .init .globl _start _start: b main .section .text main: mov sp,#0x8000 /*Configure GPIO18 as PWM0 output, which is ALT Fun 5 setting in the register 10b=2 decimal*/ mov r0,#18 mov ...

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