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by jdb
Thu Jul 15, 2021 7:33 pm
Forum: Off topic discussion
Topic: I have a dream
Replies: 8
Views: 1003

Re: I have a dream

Feature request thread. Locked.
by jdb
Tue Jul 13, 2021 5:50 pm
Forum: General
Topic: Realistically will we ever see more variants of this chip?
Replies: 39
Views: 2389

Re: Realistically will we ever see more variants of this chip?

- internal oscillator good enough for usb/uart Good call - I can live without USB and I can go slow on the debug serial or GPS or whatever so don't need it to be hugely stable or run at much more than 2 or 4MHz. This is hard to do without exploding the complexity of the oscillator. The ring oscilla...
by jdb
Tue Jul 13, 2021 5:36 pm
Forum: General
Topic: which GPIOs are connected to which IOVDD ?
Replies: 1
Views: 221

Re: which GPIOs are connected to which IOVDD ?

The IOVDD domain is routed through each digital IO pad on the die. See section 5.2.2.2 in the datasheet.

All IOVDD pads must be connected, and suitably decoupled, for ESD tolerance and GPIO performance to be met.
by jdb
Sun Jul 11, 2021 6:00 pm
Forum: General
Topic: RP2040 with internal oszilator
Replies: 6
Views: 458

Re: RP2040 with internal oszilator

yeah I read that (1.8 to 12MHz) - but I thought this wide range is while booting and I assumed, that this will stabilize later. How does this work with the Bootloader? Does the Bootloader in the boot rom use external clock for its usb support? and what happens when there is none? ROM bootloader + U...
by jdb
Sun Jul 11, 2021 5:53 pm
Forum: SDK
Topic: ROM
Replies: 9
Views: 774

Re: ROM

WizIO wrote:
Sun Jul 11, 2021 2:29 pm
my question is:

is OTP ( One - Time - Programing ) or not ?
I'm assuming that you're asking about chip-internal storage rather than the bootloader ROM - there are no one-time programmable (OTP) elements or flash memory anywhere in RP2040.
by jdb
Sun Jul 11, 2021 5:49 pm
Forum: General
Topic: Realistically will we ever see more variants of this chip?
Replies: 39
Views: 2389

Re: Realistically will we ever see more variants of this chip?

It took three years to make this RP2040 version. It would be a shame to waste that IP. We built two things while building RP2040: - RP2040 - A business unit that can make ASICs Variants of RP2040? Most likely yes, but only once we've worked out where RP2040 fits and where it doesn't fit, and if it'...
by jdb
Fri Jul 09, 2021 9:32 pm
Forum: General discussion
Topic: [Solved] How to remap Logitech (or other) keyboards with GUI
Replies: 5
Views: 310

Re: Keyboard remap needed at boot

if you don't know FOR CERTAIN, please do not post speculative posts, as it will waste time and space. Because of your (continuing) attitude I am not going to waste my time looking to see if I can come up with a solution for you. Why did you waste time bothering to making a post, then? And in doing ...
by jdb
Fri Jul 09, 2021 9:26 pm
Forum: General discussion
Topic: Videocore 6 documentation
Replies: 40
Views: 2394

Re: Videocore 6 documentation

What does that statement have to do with documentation for Videocore? As an open-source hardware design, RISC-V would presumably be packaged with an open-source GPU, or at least an open-source friendly GPU like Mali. Please provide evidence that Mali is an "open-source friendly" GPU. Btw,...
by jdb
Wed Jul 07, 2021 10:12 pm
Forum: General discussion
Topic: Videocore 6 documentation
Replies: 40
Views: 2394

Re: Videocore 6 documentation

sandwich wrote:
Wed Jul 07, 2021 10:10 pm
jamesh wrote:
Wed Jun 16, 2021 10:35 pm
Eben no longer works for Broadcom, full time CEO of Trading.
If that's the case, hopefully he is not beholden to them any more. Maybe a RISC-V variant of the Pi is possible?
What does that statement have to do with documentation for Videocore?
by jdb
Wed Jul 07, 2021 10:11 pm
Forum: General discussion
Topic: Pi's history of weird, niche hardware choices.
Replies: 55
Views: 2838

Re: Pi's history of weird, niche hardware choices.

I have never had a single micro-USB connector fail on any product I have owned. I had to replace several microusb cables that first work fine for months but later start to show low voltage warnings with Pi3b, Pi3b+. I guess it is some sort of oxidization inside the microusb connector (due to repeat...
by jdb
Wed Jul 07, 2021 7:34 pm
Forum: General discussion
Topic: Pi's history of weird, niche hardware choices.
Replies: 55
Views: 2838

Re: Pi's history of weird, niche hardware choices.

To this day I still don't understand why there is this pervading opinion that "we should have used a barrel plug" despite them being literally the most garbage power connectors in commodity usage . Aside from there being no common standard or convention on plug dimension versus voltage, po...
by jdb
Wed Jul 07, 2021 3:04 pm
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2264

Re: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?

Yes. Probably by quite a bit if it supports 512 byte maxpackets.

Edit: Phreak post GET
by jdb
Wed Jul 07, 2021 2:59 pm
Forum: Off topic discussion
Topic: Razer Deathadder V2 DPI Switches
Replies: 1
Views: 617

Re: Razer Deathadder V2 DPI Switches

What happens if you add usbhid.mousepoll=0 to /boot/cmdline.txt?
by jdb
Tue Jun 22, 2021 9:09 am
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2264

Re: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?

It appears the failures and workarounds vary between Rev 1.1, 1.2 and 8 GB boards. The reproducible scenario I described is on a Raspberry Pi 4 Model B Rev 1.2 board. Kendek gets different results using an 8 GB board. I wouldn't be surprised if your tests were run on a Rev 1.1 board. So you can reb...
by jdb
Sun Jun 20, 2021 8:16 am
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2264

Re: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?

... However, subsequent reboots hang with the ACT LED on. Monitoring from a serial console only shows reboot: Restarting system and nothing after that. ... You need to enable the bootloader EEPROM debug output ( BOOT_UART=1 ) to see where it gets stuck. Mine is stuck because the bootloader unable t...
by jdb
Fri Jun 18, 2021 7:53 pm
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2264

What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?

From some tangential discussion around plugging random PCIe add-in cards to a Compute Module 4, I've discovered a quirk of Linux on ARM that may result in suboptimal performance. PCI Express has the concept of a "maximum packet size". This is the largest acceptable TLP (otherwise known as ...
by jdb
Wed Jun 16, 2021 9:40 pm
Forum: Raspberry Pi 400
Topic: Replacing keyboard connector on motherboard
Replies: 12
Views: 1392

Re: Replacing keyboard connector on motherboard

The actual part is from a specialist supplier so it will not be possible to buy just one part from them. This part should work as an alternative. https://uk.farnell.com/hirose-hrs/fh12-26s-1sh-55/connector-ffc-fpc-rcpt-26pos-1row/dp/2427721 When hand soldering these, care must be taken that any acc...
by jdb
Wed Jun 09, 2021 2:34 pm
Forum: General discussion
Topic: Discuss
Replies: 1
Views: 222

Re: Discuss

I think not. Discussion closed
by jdb
Fri Jun 04, 2021 10:15 pm
Forum: SDK
Topic: SDK 1.2 USB CDC problem
Replies: 12
Views: 695

Re: SDK 1.2 USB CDC problem

matherp wrote:
Fri Jun 04, 2021 9:50 pm
It happened but since you can't be bothered looking.....
if it happened, then you can prove it happened.
by jdb
Thu Jun 03, 2021 8:53 pm
Forum: General
Topic: RP2040 PWM Hardware Design
Replies: 6
Views: 535

Re: RP2040 PWM Hardware Design

The PWM peripheral is completely original RTL. I don't know what the design brief was, but I would imagine 2^16 counter resolution plus an arbitrary PLL-derived source clock would be sufficient for most use-cases, no?
by jdb
Wed May 26, 2021 3:08 pm
Forum: Compute Module
Topic: Kernel Panic on Compute Module 4 associated to heavy traffic over USB
Replies: 13
Views: 1886

Re: Kernel Panic on Compute Module 4 associated to heavy traffic over USB

Linux treats any xHCI controller as if it has two independent buses - USB3.0 and USB2.0. If you do lsusb -v, you'll find that the USB3.0 root hub has zero ports.
by jdb
Mon May 24, 2021 6:08 pm
Forum: General discussion
Topic: Would an M2 Sata drive reduce SD Card Curroptions
Replies: 5
Views: 380

Re: Would an M2 Sata drive reduce SD Card Curroptions

If you're constantly uploading data gathered by the Pi to the internet, meaning that there is a small amount of state stored locally at any one time, then overlayFS is for you. An option for converting the root filesystem to an overlayFS/read-only FS is available in raspi-config. See: https://www.ra...
by jdb
Tue May 18, 2021 6:53 pm
Forum: Beginners
Topic: SD card size RP3B+?
Replies: 8
Views: 352

Re: SD card size RP3B+?

I wonder if some tried A2 types here. Since Linux would have a host driver built in similar to the ones used for SATA and M.2, and we are running an OS off of it. The difference would be if the Command Queuing and Cache would help it or not. Users have tested A2 cards. They perform the same as A1 c...
by jdb
Tue May 18, 2021 6:14 pm
Forum: Beginners
Topic: Unzip ZIP BOMB Rpi4
Replies: 6
Views: 769

Re: Unzip ZIP BOMB Rpi4

DD command works, but doesn't always set up the partitions up and format them correctly on some media. DD has no concept of a "partition" nor does it know "how to set them up". The most likely cause of the zipfile warning is a corrupt file, one which is accepted on whatever soft...
by jdb
Mon May 17, 2021 6:50 pm
Forum: Troubleshooting
Topic: dead SD card
Replies: 8
Views: 734

Re: dead SD card

You want to decode the CSD, not CID, if you want the status of the write-protect bits.


https://goughlui.com/static/csdecode2.htm

edit: the card isn't reporting write-protect, which is a bit silly.

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