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by MikeDB
Sun Sep 15, 2019 10:48 am
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 228
Views: 55704

Re: Circle - C++ bare metal environment (with USB)

I'm aiming for Ethernet, USB & HDMI as Linux only and everything on the 40 pin extender as bare metal. I forgot to mention, that Circle is able to do Ethernet, USB & HDMI on its own. So maybe Linux is not needed. But of course it depends on what you want to do with it. Linux and Circle together is ...
by MikeDB
Sat Sep 14, 2019 10:40 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi4 and bcm_host_get_peripheral_address()
Replies: 3
Views: 79

Re: Pi4 and bcm_host_get_peripheral_address()

joan wrote:
Sat Sep 14, 2019 9:49 am
Don't know if it has been updated or not.

BCM2711/Pi4B peripherals base address 0xFE000000.
Isn't 0XFE000000 just the physical address so not accessable from Linux
by MikeDB
Sat Sep 14, 2019 9:33 am
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 228
Views: 55704

Re: Circle - C++ bare metal environment (with USB)

Has anybody got Circle running using Windows ? I searched but couldn't find any info on doing so. I tried this a long time ago, normally I am working on Linux only. Thanks I'll have one more attempt at making the ARM toolchain work on my Linux machine but it is an odd-ball used for a specific purpo...
by MikeDB
Sat Sep 14, 2019 9:22 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Pi4 and bcm_host_get_peripheral_address()
Replies: 3
Views: 79

Pi4 and bcm_host_get_peripheral_address()

Does 'unsigned bcm_host_get_peripheral_address()' work correctly on the Pi4 ?

If yes, I'm doing something else wrong, but if not, where are the peripherals remapped to in virtual space ?
by MikeDB
Sat Sep 14, 2019 9:17 am
Forum: Bare metal, Assembly language
Topic: Clean, OS-independent Pi programming using C/C++
Replies: 11
Views: 380

Re: Clean, OS-independent Pi programming using C/C++

For some reason people have offered a solution to your question in Pascal despite the fact you asked for C/C++. So I will take the liberty of suggesting something a bit more modern: A Raspi OS in the Rust language: https://github.com/rust-embedded/rust-raspi3-OS-tutorials I would point out that the...
by MikeDB
Sat Sep 14, 2019 4:14 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C6
Replies: 4
Views: 112

Re: I2C6

trejan wrote:
Fri Sep 13, 2019 10:55 pm
The additional peripherals in the Pi 4 are all listed in https://github.com/raspberrypi/linux/bl ... m2838.dtsi
Many thanks - that page could do with being a Sticky until they get the official peripheral specification document released
by MikeDB
Fri Sep 13, 2019 10:53 pm
Forum: Bare metal, Assembly language
Topic: Clean, OS-independent Pi programming using C/C++
Replies: 11
Views: 380

Re: Clean, OS-independent Pi programming using C/C++

pik33 wrote:
Thu Sep 05, 2019 3:22 pm
We are waiting for RPi4 compatible version: because of the big hardware revolution Ultibo can not compile for RPi4 yet.
Is there any expected timescale for at least a testable version of Ultibo for Pi4 ?
by MikeDB
Fri Sep 13, 2019 10:41 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C6
Replies: 4
Views: 112

Re: I2C6

Thanks. By any chance do you have any other base addresses for the other peripherals in Pi4 ? There doesn't seem to be a list of them anywhere yet.
by MikeDB
Fri Sep 13, 2019 8:14 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 228
Views: 55704

Re: Circle - C++ bare metal environment (with USB)

But I've hit a dead end actually setting up Circle on Windows as everything seems geared to Linux - and it does say "Building is normally done on PC Linux."

Has anybody got Circle running using Windows ? I searched but couldn't find any info on doing so.
by MikeDB
Fri Sep 13, 2019 7:35 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C6
Replies: 4
Views: 112

I2C6

Does anyone know where the registers for the I2C6 port on GPIO22/23 are, and what any control bits mean ? Addressing from bare metal C so not interested in calls via Linux

Thanks
by MikeDB
Fri Sep 13, 2019 9:17 am
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 228
Views: 55704

Re: Circle - C++ bare metal environment (with USB)

I've downloaded the Windows version for now and that seems to work. Must be something my Linux machine doesn't like
by MikeDB
Thu Sep 12, 2019 11:58 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 228
Views: 55704

Re: Circle - C++ bare metal environment (with USB)

I've tried installing the suggested toolset from the ARM site https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-a/downloads and selecting the gcc-arm-8.3-2019.03-x86_64-aarch64-elf.tar.xz link. Downloaded a 300Mbyte tar file but when extracted I don'...
by MikeDB
Thu Sep 12, 2019 4:53 pm
Forum: General discussion
Topic: BCM2711 peripherals specification document
Replies: 2
Views: 130

BCM2711 peripherals specification document

This is mentioned in the Pi4 datasheet but still seems to be unavailable. Does anyone know when it might appear, or can point me to a repository of the sort of information it will contain.

Thanks
by MikeDB
Wed Aug 21, 2019 12:08 am
Forum: Gentoo
Topic: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)
Replies: 34
Views: 3834

Re: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)

Sorry to have to ask, but could you also say what command line options you use with GCC to get proper 64 bit only code images. I've seen various comments and suggestions around which tend to vary, but it seems like you actually have it working properly so obviously must be doing it correctly. Sure;...
by MikeDB
Tue Aug 20, 2019 1:45 pm
Forum: Gentoo
Topic: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)
Replies: 34
Views: 3834

Re: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)

Sorry to have to ask, but could you also say what command line options you use with GCC to get proper 64 bit only code images.

I've seen various comments and suggestions around which tend to vary, but it seems like you actually have it working properly so obviously must be doing it correctly.
by MikeDB
Tue Aug 20, 2019 1:38 pm
Forum: Gentoo
Topic: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)
Replies: 34
Views: 3834

Re: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)

Looks very interesting but before I begin what is obviously a major download and install, could somebody tell me how long it takes to shutdown on a Pi4 ? Proper 64 bits is definitely what I need but I only have a limited backup supply keeping the processor going when the cord is pulled (which it wi...
by MikeDB
Mon Aug 19, 2019 8:44 pm
Forum: General discussion
Topic: Headphone output on Pi 4
Replies: 2
Views: 399

Re: Headphone output on Pi 4

No this is definitely a 1MHz-ish triangle wave. I was assuming much faster as well as there's nowhere near enough filtering on it for 1MHz.
by MikeDB
Mon Aug 19, 2019 8:43 pm
Forum: Gentoo
Topic: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)
Replies: 34
Views: 3834

Re: Bootable 64-bit Gentoo image for the RPi4 released (Xfce4 desktop)

Looks very interesting but before I begin what is obviously a major download and install, could somebody tell me how long it takes to shutdown on a Pi4 ? Proper 64 bits is definitely what I need but I only have a limited backup supply keeping the processor going when the cord is pulled (which it wil...
by MikeDB
Mon Aug 19, 2019 3:08 pm
Forum: General discussion
Topic: Headphone output on Pi 4
Replies: 2
Views: 399

Headphone output on Pi 4

I'm trying to feed this into external amplifiers but it keeps hanging them up. So I looked at the output with a scope and there is a clear 1MHz triangle wave which is of course anathema to a class D amplifier. I realise the output is made by PWM but I was assuming there would be more filtering. Is t...
by MikeDB
Thu Aug 15, 2019 2:23 pm
Forum: General discussion
Topic: Fast turn off of a Pi in embedded applications
Replies: 20
Views: 878

Re: Fast turn off of a Pi in embedded applications

Yes I see them now - UNDER the standard heat sink !! Well done guys :-) There is no "standard" heatsink. Any heatsink you have on a Pi4B is a third party product. Yes I see now. I ordered it from Pimoroni with the Official PSU and Noobs card, and didn't notice the heatsink wasn't 'official'.
by MikeDB
Thu Aug 15, 2019 9:17 am
Forum: General discussion
Topic: Fast turn off of a Pi in embedded applications
Replies: 20
Views: 878

Re: Fast turn off of a Pi in embedded applications

Gavinmc42 wrote:
Wed Aug 14, 2019 4:26 am
The Pi4 header pins are near USB-C connector, labelled Run and Global_en.

Yes I see them now - UNDER the standard heat sink !! Well done guys :-)
by MikeDB
Wed Aug 14, 2019 4:22 am
Forum: General discussion
Topic: Fast turn off of a Pi in embedded applications
Replies: 20
Views: 878

Re: Fast turn off of a Pi in embedded applications

I use the PiCore version of TinyCore Linux, but there is no Pi4 version yet. On older Pi's I just just pull the power anytime with PiCore. I don't dare do that with Raspbian. There is a new 3 pin header on the Pi4, i suspect it is usable for shutdown etc. There might be some write up somewhere for ...
by MikeDB
Wed Aug 14, 2019 4:16 am
Forum: General discussion
Topic: Fast turn off of a Pi in embedded applications
Replies: 20
Views: 878

Re: Fast turn off of a Pi in embedded applications

However the Pi still seems to have problems that the forums indicate people have been having since the beginning, such as unexpected power failure. Potential disk corruption on pulling power rather comes with the territory, the type of system being used, so I wouldn't class it a a specific Pi "prob...
by MikeDB
Tue Aug 13, 2019 8:11 pm
Forum: General discussion
Topic: Fast turn off of a Pi in embedded applications
Replies: 20
Views: 878

Re: Fast turn off of a Pi in embedded applications

It might be worth looking at Nard SDK. Not sure if it has all you need ... http://www.arbetsmyra.dyndns.org/nard/ From first look it could be exactly what I need. I'm new to the Pi after trying the very first model at launch and being disappointed so still catching up on the many years of ecosystem...
by MikeDB
Tue Aug 13, 2019 7:11 pm
Forum: General discussion
Topic: Fast turn off of a Pi in embedded applications
Replies: 20
Views: 878

Re: Fast turn off of a Pi in embedded applications

It sounds like the sort of thing buildroot was designed for. That is usually configured with enough infrastructure for wifi and the like (if needed), so have a look at that. Thanks - just the sort of advice I am after and I'll definitely look at it. Also looking at LibreELEC which has slightly diff...

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