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by Kendek
Mon Oct 11, 2021 3:42 pm
Forum: Troubleshooting
Topic: Can't write to ext4 partition of external drive
Replies: 18
Views: 507

Re: Can't write to ext4 partition of external drive

... I mean no disrespect to you sir. But if such a simple task like writing files to my own drive requires me or anybody else for that matter to read a manual/guide, then how will people move away from windows to linux? ... You just used the chmod in a wrong way. If you are unwilling to learn how t...
by Kendek
Mon Oct 11, 2021 3:01 pm
Forum: Troubleshooting
Topic: Can't write to ext4 partition of external drive
Replies: 18
Views: 507

Re: Can't write to ext4 partition of external drive

twilightened wrote:
Mon Oct 11, 2021 2:37 pm
...
I did not bother creating mount points so i just entered:

Code: Select all

sudo chmod 777 /dev/sda1
sudo chmod 777 /dev/sda2
However, now i realized that this only works on the root folder. It does not make the whole partition writeable. Any more advice?

Please read some guides for novice Linux users.
by Kendek
Mon Oct 11, 2021 2:26 pm
Forum: Troubleshooting
Topic: Can't write to ext4 partition of external drive
Replies: 18
Views: 507

Re: Can't write to ext4 partition of external drive

DougieLawson wrote:
Mon Oct 11, 2021 2:20 pm
Kendek wrote:
Mon Oct 11, 2021 7:38 am

Code: Select all

sudo chmod 777 /mount/point
That is exactly the wrong way. You're bypassing all Linux security permission bits and owner, group and world controls. DO NOT do this.

Ok. So then

Code: Select all

sudo chown 1000:1000 /mount/point
sudo chmod 744 /mount/point
by Kendek
Mon Oct 11, 2021 7:38 am
Forum: Troubleshooting
Topic: Can't write to ext4 partition of external drive
Replies: 18
Views: 507

Re: Can't write to ext4 partition of external drive

Code: Select all

sudo chmod 777 /mount/point
by Kendek
Wed Oct 06, 2021 2:44 pm
Forum: Advanced users
Topic: Automatically open LUKS on boot (root partition)
Replies: 1
Views: 169

Re: Automatically open LUKS on boot (root partition)

... In my head, I think the USB should somehow be mounted before LUKS asks for the passphrase. ... 6. Your /etc/crypttab may look like this now: sda3_crypt UUID=f9aefe4-13f0-1256-9309-8daeee9c127a /dev/disk/by-uuid/99821e18-abcd-de00-2156-e410836baba1:/sda3_crypt luks,keyscript=/lib/cryptsetup/scri...
by Kendek
Sun Aug 22, 2021 10:43 am
Forum: General discussion
Topic: Raspberry Pi 4b — 64-bit AES performance
Replies: 21
Views: 1667

Re: Raspberry Pi 4b — 64-bit AES performance

And I'm using a custom kernel, compiled with a newer GCC (10.3.0). Do you think it's the GCC, or are there any crypto settings that you tweaked in your kernel? I don't know for sure, but you can test it if you want: Linux 5.10.60 unmodified GCC 10.3.0 ( source code ) Linux 5.10.60 lightly customize...
by Kendek
Sun Aug 22, 2021 8:53 am
Forum: General discussion
Topic: Raspberry Pi 4b — 64-bit AES performance
Replies: 21
Views: 1667

Re: Raspberry Pi 4b — 64-bit AES performance

Thank you! So, some of these 1600 Mhz figures are higher than my 1800 Mhz. What did you tweak? I have a default Debian Buster 64-bit Kernel without modifications. Here is some additional benchmark results: # Algorithm | Key | Encryption | Decryption # 1600 MHz: xchacha12,aes-adiantum 256b 209.3 MiB...
by Kendek
Mon Aug 16, 2021 9:39 am
Forum: General discussion
Topic: Raspberry Pi 4b — 64-bit AES performance
Replies: 21
Views: 1667

Re: Raspberry Pi 4b — 64-bit AES performance

I ran some tests for 1800 MHz and 2100 MHz, unfortunately I didn't remember this thread and skipped 1900 MHz ... here are the results. 1800 MHz ... closer to Kendek, but not the same. # Algorithm | Key | Encryption | Decryption xchacha12,aes-adiantum 256b 201.7 MiB/s 196.4 MiB/s xchacha20,aes-adian...
by Kendek
Tue Jun 22, 2021 2:36 pm
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2170

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

jdb wrote:
Tue Jun 22, 2021 9:09 am
...
That's a concrete enough set of data points for a bug report - can you create an issue on https://github.com/raspberrypi/rpi-eeprom ?

I just opened an issue.
by Kendek
Sun Jun 20, 2021 8:49 am
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2170

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

... The problem can be worked around by either setting the BOOT_ORDER to boot USB-MSD first OR inserting an SD card that has no BOOT partition. ... This is a reboot with 'pci=pcie_bus_safe' added to cmdline.txt and BOOT_ORDER=0xf41: ... Trying partition: 0 Unable to read partition as FAT lba: 0 oem...
by Kendek
Sun Jun 20, 2021 7:31 am
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2170

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 Kendek
Sat Jun 19, 2021 3:59 pm
Forum: General discussion
Topic: What happens if you add pci=pcie_bus_safe to cmdline.txt on a Pi 4?
Replies: 25
Views: 2170

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

This cmdline parameter works, but it seems that the bootloader EEPROM does not compatible with it. So after the Linux kernel is loaded with pci=pcie_bus_safe option, the system will not be able to reboot from USB. The default behaviour: [ 48.303139] reboot: Restarting system ... Trying partition: 0 ...
by Kendek
Thu Jun 03, 2021 1:50 pm
Forum: Advanced users
Topic: Deactivating USB-Ports
Replies: 13
Views: 956

Re: Deactivating USB-Ports

Is uhubctl really cutting power to the usb? An idle pi 4 with no usb devices attached shows no power difference after disabling usb with uhubctl. It's just control the port power, not the USB controller power. So the difference is very minimal, if at all. How do we power off the USB controller? Tha...
by Kendek
Thu Jun 03, 2021 8:04 am
Forum: Advanced users
Topic: Deactivating USB-Ports
Replies: 13
Views: 956

Re: Deactivating USB-Ports

Uhubctl is already cutting off the power, so a passive device is dead. But if the USB device has an external power source, this may not be as effective. Is uhubctl really cutting power to the usb? An idle pi 4 with no usb devices attached shows no power difference after disabling usb with uhubctl. ...
by Kendek
Sat May 29, 2021 9:31 pm
Forum: Advanced users
Topic: Raspberry Pi 4 VL805 firmware release 0138a1
Replies: 70
Views: 38326

Re: Raspberry Pi 4 VL805 firmware release 0138a1

... I have other RPi4 that are remote that I only access by ssh. They are 64-bit. 1. Can I build the updater programs from source to run on 64-bit? 2. How can I tell what version of bootloader I have remotely from the Linux shell? You can update (re-flash) the EEPROM(s) with the rpi-boot-eeprom-rec...
by Kendek
Sat May 29, 2021 5:20 pm
Forum: Advanced users
Topic: Deactivating USB-Ports
Replies: 13
Views: 956

Re: Deactivating USB-Ports

deepo wrote:
Sat May 29, 2021 4:58 pm
It sounds like you have to create your own USB cable with a power switch in it. Or maybe they already exists?
Uhubctl is already cutting off the power, so a passive device is dead. But if the USB device has an external power source, this may not be as effective.
by Kendek
Sat May 29, 2021 1:21 pm
Forum: Advanced users
Topic: Raspberry Pi 4 VL805 firmware release 0138a1
Replies: 70
Views: 38326

Re: Raspberry Pi 4 VL805 firmware release 0138a1

The binary does not run for me. I am running Arch ARM 64-bit. Also, my lspci does not show the firmware. ... Then maybe you might want to download the latest rpi-boot-eeprom-recovery .zip file ( rpi-boot-eeprom-recovery-2021-04-29-vl805-000138a1 ) to update (re-flash) the EEPROM(s) (see README.txt)...
by Kendek
Sat May 29, 2021 9:56 am
Forum: Advanced users
Topic: Raspberry Pi 4 VL805 firmware release 0138a1
Replies: 70
Views: 38326

Re: Raspberry Pi 4 VL805 firmware release 0138a1

... How can I tell which version I have currently? I use Arch ARM and it does not have that command: $ which vl805 vl805 not found ... > lspci -d 1106:3483 -xxx | awk '/^50:/ { print "VL805 FW version: " $5 $4 $3 $2 }' VL805 FW version: 000138a1 And you can download the vl805 binary from ...
by Kendek
Sat May 29, 2021 9:33 am
Forum: Advanced users
Topic: Raspberry Pi 4 VL805 firmware release 0138a1
Replies: 70
Views: 38326

Re: Raspberry Pi 4 VL805 firmware release 0138a1

mike.NY wrote:
Sat May 29, 2021 9:24 am
Is this for RPi OS only?
No, this is an OS-independent EEPROM image, exists in a separate and embedded form.
by Kendek
Sat May 29, 2021 8:33 am
Forum: Advanced users
Topic: Deactivating USB-Ports
Replies: 13
Views: 956

Re: Deactivating USB-Ports

The uhubctl utility works great, but only controls the power of the USB ports. I think that may be enough. You can unbind the USB device driver through a sysfs interface (/sys/bus/usb/drivers/<drv_name>/unbind), but this may not be enough.
by Kendek
Sat Apr 10, 2021 8:00 am
Forum: Advanced users
Topic: DVFS Firmware
Replies: 98
Views: 25079

Re: DVFS Firmware

... Is this is the way DVFS works on Pi 4? My understanding of DVFS is, each of the supported frequencies would have a different voltage label. ... As of now, it seems that Pi 4 is only supporting frequency scaling and not DVFS, which involves a change in voltage for any change in frequency or am I...
by Kendek
Wed Apr 07, 2021 3:24 pm
Forum: Advanced users
Topic: DVFS Firmware
Replies: 98
Views: 25079

Re: DVFS Firmware

spanda wrote:
Wed Apr 07, 2021 3:21 pm
...
Any idea why DVFS is not working as there is no Voltage change.
Yes, you need

Code: Select all

dvfs=1
in your config.txt file.
by Kendek
Wed Mar 31, 2021 1:53 pm
Forum: Advanced users
Topic: DVFS Firmware
Replies: 98
Views: 25079

Re: DVFS Firmware

spanda wrote:
Tue Mar 30, 2021 5:05 pm
...
Does this firmware support DVFS with voltage change with respect to frequency change?
...
Yes, but you need

Code: Select all

dvfs=1
in the config.txt file.
by Kendek
Tue Mar 09, 2021 5:02 pm
Forum: Advanced users
Topic: Tweaking the kernel to optimize for RPi4
Replies: 6
Views: 740

Re: Tweaking the kernel to optimize for RPi4

If you want to specify the exact architecture and microarchitecture, then use

Code: Select all

-march=armv8-a+crc -mtune=cortex-a72
or

Code: Select all

-mcpu=cortex-a72+crc
by Kendek
Tue Feb 09, 2021 12:53 pm
Forum: Advanced users
Topic: Raspberry Pi 4 VL805 firmware release 0138a1
Replies: 70
Views: 38326

Re: Raspberry Pi 4 VL805 firmware release 0138a1

tmheroes wrote:
Tue Feb 09, 2021 5:54 am
Can I know a way to downgrade VLI firmware to 0137ab in rpi4 8gb?
There is no dedicated VLI EEPROM, so the firmware is integrated into the bootloader image, which is closed source.

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