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by MikeDB
Sun Sep 13, 2020 5:47 pm
Forum: Bare metal, Assembly language
Topic: Pi 4 EEPROM bootloader code
Replies: 5
Views: 375

Re: Pi 4 EEPROM bootloader code

ah, pi4 and display elimiate rpi-open-firmware from the game, it doesnt support either yet the other things you can do to speed up the pi4 boot, is to disable the hat eeprom reading force_eeprom_read=0 disable_poe_fan=1 that will stop the firmware from trying to detect your hat, which will shave a ...
by MikeDB
Sun Sep 13, 2020 9:25 am
Forum: Bare metal, Assembly language
Topic: Pi 4 EEPROM bootloader code
Replies: 5
Views: 375

Re: Pi 4 EEPROM bootloader code

depending on what you want to do (does it need to be arm? does it need to be a pi4?) you can change some factors, Yes needs to be Pi4 ... until there's something faster. Only need USB and display, no WiFi, BT or Ethernet. Thanks for info on measuring time. It's not mission critical to be fast thoug...
by MikeDB
Sat Sep 12, 2020 1:42 pm
Forum: Bare metal, Assembly language
Topic: Pi 4 EEPROM bootloader code
Replies: 5
Views: 375

Pi 4 EEPROM bootloader code

Is the 64bit EEPROM bootloader private or publically available to modify ? I'd like to cut out some of the stuff from the boot sequence to get to running the bare metal code a little bit faster if possible. I notice it looks for things like recovery files then declares them missing, which they are. ...
by MikeDB
Fri Sep 11, 2020 6:29 pm
Forum: General discussion
Topic: STICKY: Raspberry Pi OS (64 bit) beta test version feedback
Replies: 354
Views: 65824

Re: STICKY: Raspberry Pi OS (64 bit) beta test version feedback

Thanks. Is there a "beginners thread" for 64bit OS installation and usage, so I can ask further basic questions there ? Or should I just post over in the beginners forum ? eg basic questions like :- having installed 64bit OS from scratch, when I go to sudo apt install something and it can't find a ...
by MikeDB
Mon Sep 07, 2020 10:16 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

Hello rst I've started porting some of my code across to Circle and USB and audio are working well even if I can't hotplug the keyboards yet. However I would like to not have a HDMI monitor present. I found this post from years ago : Been trying to make some simple programs work but seem to be hitti...
by MikeDB
Mon Sep 07, 2020 12:13 am
Forum: General discussion
Topic: STICKY: Raspberry Pi OS (64 bit) beta test version feedback
Replies: 354
Views: 65824

Re: STICKY: Raspberry Pi OS (64 bit) beta test version feedback

Is anybody else having issues getting booting from a USB flash drive working for the 64bit OS ? It always works in the end for me, but only after several attempts. Still got several Pi4s to upgrade. For reference I am following this procedure exactly so maybe it is at fault https://www.tomshardware....
by MikeDB
Thu Sep 03, 2020 8:39 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

rst wrote:
Thu Sep 03, 2020 3:54 pm
;) Honestly one can currently effectively use "only" 3GB of that memory with Circle.
I'll struggle through :D

At 96kHz even 3Gbyte makes an 86 minute long stereo reverb :shock:
by MikeDB
Thu Sep 03, 2020 3:12 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

rst wrote:
Wed Sep 02, 2020 11:48 am
Circle already has xHCI support, but without plug-and-play so far. That's going to be changed now. The property mailbox call for RPi 4B 8GB models is also included in the latest release.
8GByte in an embedded processor application ! I remember squeezing code into a 6805 with 8kbits (1kbyte) !
by MikeDB
Tue Sep 01, 2020 10:15 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Dashbord with 4 gauges from 4 displays
Replies: 14
Views: 676

Re: Dashbord with 4 gauges from 4 displays

Appologies if you've already considered this but it looks like some of the gauges you want to replace are safety critical. Check local roadworthiness regulations. Check requirements for instrument accuracy (especially for things like speedometer and odometer) Check the impact to your car insurance....
by MikeDB
Tue Sep 01, 2020 8:55 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

@MikeDB I had a look on how USB plug-and-play (PnP) can be implemented in Circle. I found a way that both application types (PnP-aware and not PnP-aware) can coexist in Circle, so that existing applications do not need to be modified and new applications can use PnP. The initial attempt of implemen...
by MikeDB
Tue Aug 25, 2020 4:28 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

rst wrote:
Tue Aug 25, 2020 3:24 pm
@MikeDB OK, I will have a look on it. Powering off the device at any time should not be a problem with a bare metal solution.
Yes that's why I want to give up on Linux. Have you had any luck finding a VL805 datasheet ? Or documentation from RPi on how they have used it ?
by MikeDB
Tue Aug 25, 2020 12:48 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

@MikeDB I understand, what the problem is. I can have a look at USB host-plugging, but as I said, it will take time and I cannot make promises. Given that Circle is still a (basically one-man) hobby project and for a professional device I would recommend the Linux solution. Maybe I underestimate, w...
by MikeDB
Tue Aug 25, 2020 10:23 am
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

I must be missing something, I simply don't get the issue in that application Circle has threads doesn't it? a.) Any new device announces itself to device 0 you just need a low priority thread to look for announcement and trigger rescan. b.) If you are starting a new baremetal app you do a windows ...
by MikeDB
Mon Aug 24, 2020 6:37 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

@MikeDB Yes, the Circle USB stack does not support hot-plugging. .... On the RPi 4 with its xHCI controller, this would not be a problem any more. There is already a solution in Circle for USB mass-storage devices (e.g. flash drives), which can be attached or removed from a running system on applic...
by MikeDB
Sun Aug 23, 2020 11:00 pm
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

If I read the Known Issues page on Githib correctly any USB device connected to the Pi using Circle has to be there at boot. Whilst adding plug and play would be a major task, I was wondering if it would be possible to just reset the USB initialisation handling, perhaps by use of a pushbutton to a G...
by MikeDB
Sun Aug 23, 2020 10:53 pm
Forum: General discussion
Topic: How necessary is extra cooling for the RPi4 now?
Replies: 26
Views: 1923

Re: How necessary is extra cooling for the RPi4 now?

I tortured the Pi4 at 141 degrees Celsius CPU temp at 1500MHz with cpuburn and it worked fine (but I did not test longterm, just for a day). Just as well - the MTBF will be about 85 times shorter than running at 60 degC :-) And you've cooked all the caps. Fortunately no electrolytics on a Pi or the...
by MikeDB
Sun Aug 23, 2020 1:23 pm
Forum: General programming discussion
Topic: Cross-compilation on a 64 bit Pi
Replies: 7
Views: 413

Re: Cross-compilation on a 64 bit Pi

I was thus thinking of replacing the master Pi4 with a 8Gb one and adding a monitor so that I could compile on it and then send the slave program copies to the other 7. Yes OK. You don't need the monitor to compile on the master Pi4. You could ssh into the master Pi4 and do the build and distribute...
by MikeDB
Sun Aug 23, 2020 10:31 am
Forum: General programming discussion
Topic: Cross-compilation on a 64 bit Pi
Replies: 7
Views: 413

Re: Cross-compilation on a 64 bit Pi

Has anybody tried this route - did it work or what were the roadblocks ? I have in the past built stuff on a Pi3 targeting the Pi Zero (the Pi Zero is slow), but most of the time its not worth while. If your Pi's are Pi3 (or better Pi4's) then both 32 and 64 bit OS's come with decent compilers whic...
by MikeDB
Sat Aug 22, 2020 7:37 pm
Forum: General programming discussion
Topic: Cross-compilation on a 64 bit Pi
Replies: 7
Views: 413

Cross-compilation on a 64 bit Pi

I asked this in Bare Metal but in fact it applies to Linux use as well Since I last looked almost a year ago I notice ARM have now added AArch64 Linux hosted cross compilers (https://developer.arm.com/tools-and-sof ... /downloads). Now we have the 64bit OS for the Pi4 this possibly means one could a...
by MikeDB
Sat Aug 22, 2020 10:27 am
Forum: Bare metal, Assembly language
Topic: Circle - C++ bare metal environment (with USB)
Replies: 296
Views: 90421

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

Since I last looked at Circle almost a year ago I notice ARM have now added AArch64 Linux hosted cross compilers (https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-a/downloads). Now we have the 64bit OS for the Pi4 this possibly means one could devel...
by MikeDB
Fri Aug 21, 2020 9:50 am
Forum: General discussion
Topic: STICKY: Raspberry Pi OS (64 bit) beta test version feedback
Replies: 354
Views: 65824

Re: STICKY: Raspberry Pi OS (64 bit) beta test version feedback

Brad Q wrote:
Tue Aug 18, 2020 8:46 pm
Is there a link with a summary of where the 64bit is at this time? Things like hardware video support, etc.

Thanks
This would be very useful, perhaps as a sticky somewhere so we know what to expect when trying it out, or to keep an eye on to know when it's worth another try.
by MikeDB
Wed Aug 19, 2020 7:01 pm
Forum: General discussion
Topic: STICKY: Raspberry Pi OS (64 bit) beta test version feedback
Replies: 354
Views: 65824

Re: STICKY: Raspberry Pi OS (64 bit) beta test version feedback

I thought I'd give this a go now it should be a little more stable but after an afternoon getting nowhere with a 4G Pi4 I'll summarize my problem. I have a 32" Samsung 4k monitor which Pis always give very small text on so in the 32 bit system I use raspi-config to set a 1920x1060 resolution so as t...
by MikeDB
Fri Feb 28, 2020 8:56 pm
Forum: General programming discussion
Topic: Is there an open source firmware for the Raspberry Pi computers?
Replies: 21
Views: 4151

Re: Is there an open source firmware for the Raspberry Pi computers?

Have a look at the STM32MP157. Not sure if everything is open-source but most STMicro stuff is.
by MikeDB
Sat Jan 04, 2020 9:38 pm
Forum: Gentoo
Topic: ALSA USB MIDI failing to initialise
Replies: 3
Views: 1139

Re: ALSA USB MIDI failing to initialise

sakaki wrote:
Sat Jan 04, 2020 11:43 am
Hi MikeDB,

MIDI isn't something I've played with on the RPi3/4 unfortunately. I'd suggest posting your issue on the Gentoo forums, as someone there may be better able to assist.

Best, sakaki
A friend has it working on Gentoo on x86 - it seems to be a Pi4 thing
by MikeDB
Fri Jan 03, 2020 1:02 am
Forum: Gentoo
Topic: ALSA USB MIDI failing to initialise
Replies: 3
Views: 1139

ALSA USB MIDI failing to initialise

I thought I'd give the latest Gentoo for Pi4 another try and it does seem more stable and works with my 4k Samsung monitor at last, although it first time boots in such a small font I had to guess what it was saying whilst trying to make it readable. Anyway whilst being more stable, I cannot get the...

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