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by ehem
Fri May 22, 2020 11:29 pm
Forum: Off topic discussion
Topic: Python 2 EoL...at least in theory
Replies: 51
Views: 4790

Re: Python 2 EoL...at least in theory

They can almost certainly be automated. Worst case, write a Python 2 interpreter in Python 3 and you should be able to continue running Python 2 within Python 3. I haven't done anything very gnarly with Python, but 2 and 3 are mostly fairly compatible. ... No, Heater's right. Although there are som...
by ehem
Fri May 22, 2020 10:35 pm
Forum: Off topic discussion
Topic: In which language is Chromium OS written?
Replies: 5
Views: 875

Re: In which language is Chromium OS written?

Did they used Assembly for low level code as I know that they had to change some things to make booting a lot faster? Most OSes include a little bit (10000-50000 lines per processor architecture) of assembly language for portions of booting and interfacing with processor features. Assembly language...
by ehem
Fri May 22, 2020 9:43 pm
Forum: General discussion
Topic: Raspberry Pi 4 USB mass storage beta (beta means it not ready yet, and not officially released!)
Replies: 282
Views: 89854

Re: Raspberry Pi 4 USB mass storage beta

As with Pi 3 the bootloader enumerates USB devices and when it finds a mass storage device it checks if the partition defined by the PM_RSTS register is present, FAT. It then processes config.txt and start.elf before booting or proceeding to the next device. There is deliberately nothing to control...
by ehem
Fri May 22, 2020 5:34 am
Forum: General discussion
Topic: Raspberry Pi 4 USB mass storage beta (beta means it not ready yet, and not officially released!)
Replies: 282
Views: 89854

Re: Raspberry Pi 4 USB mass storage beta

It will boot from the drive with the bootable OS on it. Not sure why you think this is a problem (it isn't). I almost always have more that one drive on my computers, including the USB booted Pi 4B2 I'm replying from now. The Pi won't try to boot from a drive that is not bootable (a data drive). Yo...
by ehem
Fri May 22, 2020 3:33 am
Forum: General discussion
Topic: Raspberry Pi 4 USB mass storage beta (beta means it not ready yet, and not officially released!)
Replies: 282
Views: 89854

Re: Raspberry Pi 4 USB mass storage beta

Will a dumb USB2 key with MBR and FAT-only end up taking precedence over a USB3 which has a GPT and all the data the RP4 needs to boot? Depends on what's bootable. USB devices are enumerated in the order they are seen by the OS. If both are bootable, then the one that is ready first will boot, and ...
by ehem
Fri May 22, 2020 2:57 am
Forum: Off topic discussion
Topic: Python 2 EoL...at least in theory
Replies: 51
Views: 4790

Re: Python 2 EoL...at least in theory

As it stands Python 2 programs do not run under Python 3. That smells like a different language. Not only the the changes are not so trivial and some are impossible find easily without looking at all your code carefully. This cannot be automated. They may be no errors from the run time. They can al...
by ehem
Fri May 22, 2020 2:37 am
Forum: General discussion
Topic: Raspberry Pi 4 USB mass storage beta (beta means it not ready yet, and not officially released!)
Replies: 282
Views: 89854

Re: Raspberry Pi 4 USB mass storage beta

Come to think of it, another issue of USB boot behavior comes to mind: What order do USB devices get probed in? This is an issue if I've got two USB storage capable devices plugged in. Will a dumb USB2 key with MBR and FAT-only end up taking precedence over a USB3 which has a GPT and all the data th...
by ehem
Fri May 22, 2020 2:18 am
Forum: General discussion
Topic: Installing Xen on Raspberry Pi
Replies: 14
Views: 7094

Re: Installing Xen on Raspberry Pi

Other gotchas: when the Dornerworks notes say it only supports 1Gb system memory, it boots on my Pi with 4 Gb, so hopefully that just means it ignores the extra 3 Gb. However, when it says it doesn't support HDMI, it's serious - it won't even boot unless you unplug your monitor. Due to reading an a...
by ehem
Thu May 21, 2020 11:33 pm
Forum: General discussion
Topic: Raspberry Pi 4 USB mass storage beta (beta means it not ready yet, and not officially released!)
Replies: 282
Views: 89854

Re: Raspberry Pi 4 USB mass storage beta

GPT is supported for USB mass storage boot only. SD card GPT will come later because that's different legacy file system code to untangle in start.elf (future rpi-update). No official support for hybrid MBR but you might get away with it so long as the VC boot partition is always first plausible EF...
by ehem
Wed Jan 15, 2020 6:25 am
Forum: Bare metal, Assembly language
Topic: Status of U-Boot Support for Pi 4
Replies: 12
Views: 3602

Re: Status of U-Boot Support for Pi 4

There are a few OSes that already use U-boot on the pi. Whenever I come across it in an OS I am converting to NOOBS or PINN, I have to strip it out and revert to the standard bootloader because it prevents multi-boot. Actually, could you list these? They may be valuable as samples for figuring out ...
by ehem
Wed Jan 15, 2020 12:36 am
Forum: Bare metal, Assembly language
Topic: Status of U-Boot Support for Pi 4
Replies: 12
Views: 3602

Re: Status of U-Boot Support for Pi 4

There are a few OSes that already use U-boot on the pi. Whenever I come across it in an OS I am converting to NOOBS or PINN, I have to strip it out and revert to the standard bootloader because it prevents multi-boot. It seems U-boot needs to exist on the first partition and all partition reference...
by ehem
Tue Jan 14, 2020 11:12 pm
Forum: General discussion
Topic: Can read from, but can't write to USB drive
Replies: 19
Views: 1552

Re: Can read from, but can't write to USB drive

Is there not a better format for the drive that will be cross-compatible with the Mac and the RPi? Yes, there is. UDF . Support varies from OS to OS, but most OSes have at least read support. Only very recent versions of the Linux UDF Tools include a `fsck` program which is worrisome for data integ...
by ehem
Tue Jan 14, 2020 2:42 am
Forum: Bare metal, Assembly language
Topic: Status of U-Boot Support for Pi 4
Replies: 12
Views: 3602

Re: Status of U-Boot Support for Pi 4

I'm guessing Raspberry Pi4Bs are officially supported by U-Boot? I'm guessing based upon how long ago this discussion was and how recently the referred repositories were updated. Sounds like all (at least most ) of the support is present in the main U-Boot repository ( GitHub being a mirror)? Looks ...
by ehem
Tue Jan 14, 2020 12:38 am
Forum: Advanced users
Topic: Using a Pi as an X-server for another computer.
Replies: 6
Views: 713

Re: Using a Pi as an X-server for another computer.

It should be some simple configuration, to get the Pi to act this way, does anyone know how to go about this? Anyone know how you would start? The "old school" way is to allow remote xclients to access the Pi's xserver via tcp... There are newer (more secure) ways that use other protocols but to ge...
by ehem
Mon Jan 13, 2020 11:14 pm
Forum: General discussion
Topic: Can read from, but can't write to USB drive
Replies: 19
Views: 1552

Re: Can read from, but can't write to USB drive

To get more data about a GPT disk you can't use fdisk. You need to use sudo sfdisk -l /dev/sda The program most often present as /sbin/fdisk is not the olde `fdisk` program you're used to. In fact the program most likely in /sbin/fdisk shares much of its core source with `sfdisk`. The modern Linux ...
by ehem
Sun Dec 22, 2019 6:47 pm
Forum: General discussion
Topic: Raspberry Pi 4 usb boot?
Replies: 574
Views: 230921

Re: Raspberry Pi 4 usb boot?

usb-boot works equally well on the Raspberry Pi 1, 2, 3, and 4. I'm pretty sure that has its own built-in assumptions which can be broken. For example if someone is trying to use the UEFI as a second-stage, then chaining to GRUB (there are things which can easily be done with GRUB which I rather do...
by ehem
Sun Dec 22, 2019 6:08 pm
Forum: Debian
Topic: Modules for 4.19 on RP4?
Replies: 1
Views: 1080

Re: Modules for 4.19 on RP4?

I was originally asking this in the hope my project could be workable with a kernel close to a generic Debian kernel plus a few patches. Then I looked at the git history of the relevant kernel source code. The Raspbian kernel closely follows Greg Kroah-Hartman's branch, this is the official 4.19.89 ...
by ehem
Sun Dec 22, 2019 5:53 pm
Forum: General discussion
Topic: Raspberry Pi 3B+ and arm processor security
Replies: 9
Views: 836

Re: Raspberry Pi 3B+ and arm processor security

Yeah, this only becomes a problem when EL2 or 3 are used. Until then nothing to worry about. A hypervisor could be compromised this way. Very first sentence "Multiple people on here have been experimenting with hypervisors (notably Xen)." The paper was talking about a RP3, but the same concern exis...
by ehem
Sun Dec 22, 2019 5:42 pm
Forum: General discussion
Topic: RPi4 implementation progress/status
Replies: 7
Views: 938

Re: RPi4 implementation progress/status

With regard to DPMS powerdown, since the power down via monitor works OK (i.e. Huge majority of monitors power down when the HDMI shuts down which is how it currently works), I doubt I will spend much/any time on working out how to do DPMS power down. Waiting for it would be inadvisable. What I was...
by ehem
Tue Dec 17, 2019 2:28 am
Forum: General discussion
Topic: RPi4 implementation progress/status
Replies: 7
Views: 938

Re: RPi4 implementation progress/status

I suspect each person has a distinct list of things they're waiting on from the RPF. Mine include: USB(3) boot DPMS powerdown Information on RP4 v1.2 differences Roughly in order of priority I'm looking for them. While the last will be interesting news, USB3 booting makes a distinctly larger differe...
by ehem
Tue Dec 17, 2019 2:15 am
Forum: General discussion
Topic: Raspberry Pi 3B+ and arm processor security
Replies: 9
Views: 836

Re: Raspberry Pi 3B+ and arm processor security

When you already have EL1 privileges (kernel) you can do everything you want anyway including manipulating the files on the boot partition. Everything higher than EL1 is not used as far as i know and there is no chain of trust at all. So it's not very secure in the first place. Multiple people on h...
by ehem
Fri Dec 13, 2019 6:23 am
Forum: Debian
Topic: Modules for 4.19 on RP4?
Replies: 1
Views: 1080

Modules for 4.19 on RP4?

Is anyone using the generic 4.19 arm64 kernel on a Raspberry PI 4? Could you list which modules are being loaded to drive the on-board SDHC/MMC hardware?

I'm experimenting with a rather unusual setup on a closely related variant and as a result retrieving that information is a bit tricky...
by ehem
Wed Dec 11, 2019 12:51 am
Forum: General discussion
Topic: New Pi 4B v1.2?
Replies: 331
Views: 67776

Re: New Pi 4B v1.2?

cjan wrote:
Wed Dec 11, 2019 12:40 am
so, after a lot of discuss, does v1.2 exist?
and, whats improve?
To the first, "yes". To the second, presently unknown.
by ehem
Thu Dec 05, 2019 10:41 pm
Forum: General discussion
Topic: New Pi 4B v1.2?
Replies: 331
Views: 67776

Re: New Pi 4B v1.2?

The Raspberry PI 4B-4GB bought at MicroCenter on Sunday appears to be the v1.2 board. Why not just ask the operating system what board you're running. grep -i 'revision' /proc/cpuinfo then decode the revision number (heres a clue: the last digit is the version) cat /sys/firmware/devicetree/base/mod...
by ehem
Thu Dec 05, 2019 6:32 am
Forum: General discussion
Topic: New Pi 4B v1.2?
Replies: 331
Views: 67776

Re: New Pi 4B v1.2?

The last bit of hardware has shown up and now I'm starting towards my project. The Raspberry PI 4B-4GB bought at MicroCenter on Sunday appears to be the v1.2 board. I took pictures, but not being on any of the big photo-sharing sites (nor steal-your-face Book) I don't have a handy place to stash the...

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