Pavel Machek
Posts
1861Following
92Followers
172
Pavel Machek
pavel
@hrw @blog Well.. yes, one of failures was that Enigma used symetric crypto. More serious failure was that key space was basically 27^3, which is so small it can be broken by hand. There is important point author is missing: RSA is very, very, _very_ bad cipher and needs good symetric cypher to be useful. You can only safely encrypt big, random numbers using RSA.
0
0
1
Pavel Machek
pavel
Tak hnusny pocasi ze i holuby chodej pesky
Vyjizdku jsme stihli, ale ted se venku zacinaj dit nepekny veci. Vypada to na bourku a neprijenou. A koukam, na strese boxu sedi holub, a vypada min plachej nez obvykle. A taky ze jo, na nohach krouzky. "Kamo, let radej jinam, tady je to sama kocka..."
Vyjizdku jsme stihli, ale ted se venku zacinaj dit nepekny veci. Vypada to na bourku a neprijenou. A koukam, na strese boxu sedi holub, a vypada min plachej nez obvykle. A taky ze jo, na nohach krouzky. "Kamo, let radej jinam, tady je to sama kocka..."
0
0
1
Pavel Machek
pavel
Wargame podcast -- je na yt, "False Flag ｜ The Wargame Ep 1 [9LEbjMAkU4I]", protrpel jsem za vas, abyste vy nemuseli. 5 hodin dramatu, kde rusove prekroci hranici pro atomovou odvetu v prvnim kroku, a vedeni UK je tak nekompetentni, ze neodpovi. To, ze se v poslednich 10ti minutach dozvime, ze by to takhle proste byt nemohlo, to nezachrani.
Wargame podcast -- ignore it. Not nearly realistic, not worth watching.
Wargame podcast -- ignore it. Not nearly realistic, not worth watching.
0
0
1
Pavel Machek
pavel
@lkundrak The 737 Handbook
dstoSenorp1t1tfhlm5u8u930u4l2at4uuu2m7943h32ahg2u01cg3tcti55 ·
Preliminary report for Air India is out. Here are main excerpts:
- 08:08:42: Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec
- In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff.
The other pilot responded that he did not do so.
- 08:08:52: Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN
- 08:08:56: the Engine 2 fuel cutoff switch also
transitions from CUTOFF to RUN
The EGT was observed to be rising for both engines indicating relight. Engine 1’s core
deceleration stopped, reversed and started to progress to recovery. Engine 2 was able to
relight but could not arrest core speed deceleration and re-introduced fuel repeatedly to
increase core speed acceleration and recovery.
- The EAFR recording stopped at 08:09:11
UTC
There's good video, too -- yt.
Air\ India\ Preliminary\ Report\ 11\ July\ \[wA_UZeHZwSw\]
And right, that does not look like mechanical failure any more.
dstoSenorp1t1tfhlm5u8u930u4l2at4uuu2m7943h32ahg2u01cg3tcti55 ·
Preliminary report for Air India is out. Here are main excerpts:
- 08:08:42: Engine 1 and Engine 2 fuel cutoff switches transitioned from RUN to CUTOFF position one after another with a time gap of 01 sec
- In the cockpit voice recording, one of the pilots is heard asking the other why did he cutoff.
The other pilot responded that he did not do so.
- 08:08:52: Engine 1 fuel cutoff switch transitioned from CUTOFF to RUN
- 08:08:56: the Engine 2 fuel cutoff switch also
transitions from CUTOFF to RUN
The EGT was observed to be rising for both engines indicating relight. Engine 1’s core
deceleration stopped, reversed and started to progress to recovery. Engine 2 was able to
relight but could not arrest core speed deceleration and re-introduced fuel repeatedly to
increase core speed acceleration and recovery.
- The EAFR recording stopped at 08:09:11
UTC
There's good video, too -- yt.
Air\ India\ Preliminary\ Report\ 11\ July\ \[wA_UZeHZwSw\]
And right, that does not look like mechanical failure any more.
1
0
0
Pavel Machek
pavel
@datenwolf Ok, time to ask the lists:
Hi!
It seems that DMA-BUFs are always uncached on arm64... which is a
problem.
I'm trying to get useful camera support on Librem 5, and that includes
recording vidos (and taking photos).
memcpy() from normal memory is about 2msec/1MB. Unfortunately, for
DMA-BUFs it is 20msec/1MB, and that basically means I can't easily do
760p video recording. Plus, copying full-resolution photo buffer takes
more than 200msec!
There's possibility to do some processing on GPU, and its implemented here:
https://gitlab.com/tui/tui/-/tree/master/icam?ref_type=heads
but that hits the same problem in the end -- data is in DMA-BUF,
uncached, and takes way too long to copy out.
And that's ... wrong. DMA ended seconds ago, complete cache flush
would be way cheaper than copying single frame out, and I still have
to deal with uncached frames.
So I have two questions:
1) Is my analysis correct that, no matter how I get frame from v4l and
process it on GPU, I'll have to copy it from uncached memory in the
end?
2) Does anyone have patches / ideas / roadmap how to solve that? It
makes GPU unusable for computing, and camera basically unusable for
video.
Best regards,
Pavel
Hi!
It seems that DMA-BUFs are always uncached on arm64... which is a
problem.
I'm trying to get useful camera support on Librem 5, and that includes
recording vidos (and taking photos).
memcpy() from normal memory is about 2msec/1MB. Unfortunately, for
DMA-BUFs it is 20msec/1MB, and that basically means I can't easily do
760p video recording. Plus, copying full-resolution photo buffer takes
more than 200msec!
There's possibility to do some processing on GPU, and its implemented here:
https://gitlab.com/tui/tui/-/tree/master/icam?ref_type=heads
but that hits the same problem in the end -- data is in DMA-BUF,
uncached, and takes way too long to copy out.
And that's ... wrong. DMA ended seconds ago, complete cache flush
would be way cheaper than copying single frame out, and I still have
to deal with uncached frames.
So I have two questions:
1) Is my analysis correct that, no matter how I get frame from v4l and
process it on GPU, I'll have to copy it from uncached memory in the
end?
2) Does anyone have patches / ideas / roadmap how to solve that? It
makes GPU unusable for computing, and camera basically unusable for
video.
Best regards,
Pavel
0
0
0
Pavel Machek
pavel
@NekoCWD @QuadRadical @libcamera That's back camera on OnePlus 6? Nice! I guess autofocus should be on by default for most cameras. (But different af implementation is suitable for still photos and for video capture, in some cases; video one is probably suitable default).
0
0
2
Pavel Machek
pavel
@datenwolf gpu -> cpu after debayer. Same problem exists with camera -> cpu, but that's less critical.
1
0
0
Pavel Machek
pavel
@datenwolf I'm still hitting uncached memory... so things are 10x slower than they should be. Is there way to get data from dmabuf to CPU without dealing with that? With 500x400 resolution I can make the deadlines, but it hurts at higher resolutions and is just wrong.
1
0
0
Pavel Machek
pavel
@NekoCWD @libcamera I see the behaviour is very different from Librem 5. It is good to see another phone working.
1
0
0
Pavel Machek
pavel
Subject: Sasha Levin is halucinating, non human entity, has no ethics and no memory
Hi!
So... I'm afraid subject is pretty accurate. I assume there's actual human being called "Sasha Levin" somewhere, but I interact with him via email, and while some interactions may be by human, some are written by LLM but not clearly marked as such.
And that's not okay -- because LLMs lie, have no ethics, and no memory, so there's no point arguing with them. Its just wasting everyone's time. People are not very thrilled by 'Markus Elfring' on the lists, as he seems to ignore feedback, but at least that's actual human, not a damn LLM that interacts as human but then ignores everything.
Do we need bot rules on the list?
Oh, and if you find my email offensive, feel free to ask LLM to change the tone.
Best regards,
Pavel
Hi!
So... I'm afraid subject is pretty accurate. I assume there's actual human being called "Sasha Levin" somewhere, but I interact with him via email, and while some interactions may be by human, some are written by LLM but not clearly marked as such.
And that's not okay -- because LLMs lie, have no ethics, and no memory, so there's no point arguing with them. Its just wasting everyone's time. People are not very thrilled by 'Markus Elfring' on the lists, as he seems to ignore feedback, but at least that's actual human, not a damn LLM that interacts as human but then ignores everything.
Do we need bot rules on the list?
Oh, and if you find my email offensive, feel free to ask LLM to change the tone.
Best regards,
Pavel
1
0
1
Pavel Machek
pavel
@NekoCWD Hi! libcamera people told me you are working on autofocus for libcamera. I got that to work with great hacks at Librem 5 at one point: https://lists.libcamera.org/pipermail/libcamera-devel/2025-April/049734.html . Is your code public somewhere? What hardware are you using?
1
0
0
Pavel Machek
pavel
How to install librem5 without an installer?
root@pureos:~# mount / -oremount,ro
mount: /: mount point is busy.
root@pureos:~# echo u > /proc/sysrq-trigger
root@pureos:~# mkdir /bar
mkdir: cannot create directory ‘/bar’: Read-only file system
root@pureos:~# cat /dev/sda > /dev/mmcblk0
root@pureos:~# sync
bash: /usr/bin/sync: cannot execute binary file: Exec format error
root@pureos:~#
root@pureos:~# mount / -oremount,ro
mount: /: mount point is busy.
root@pureos:~# echo u > /proc/sysrq-trigger
root@pureos:~# mkdir /bar
mkdir: cannot create directory ‘/bar’: Read-only file system
root@pureos:~# cat /dev/sda > /dev/mmcblk0
root@pureos:~# sync
bash: /usr/bin/sync: cannot execute binary file: Exec format error
root@pureos:~#
1
0
0
Pavel Machek
pavel
Hey, world. I need Mobian installer for Librem 5, but the directory where it should be is empty. What is going on?
0
0
1