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Old 05-14-2017, 06:00 PM   #1
kdusr
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hot to delete a file in kindle /usr/share/blanket/screensaver/

I try to delete a file at
/usr/share/blanket/screensaver/
but got error message : readonly file system, checked permisson of the files and folder , it is 755, no permission to write or delete

tried su command, does not work,
is that possible to delete kindle system file at /usr/share/blanket/screensaver/

anyone give me a hint, thanks!
just want to a blank screensaver
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Old 05-14-2017, 06:19 PM   #2
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Originally Posted by kdusr View Post
- - - -

anyone give me a hint, thanks!
just want to a blank screensaver
At the command line, enter:
mount

No you do not, removing them will not do what you wish to happen.
For the reasons why not, read my prior post.

Also, read the information about using USBnetworking then use it over USB long enough to learn what is different from using it over WiFi.

Last edited by knc1; 05-14-2017 at 06:21 PM.
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Old 05-14-2017, 07:00 PM   #3
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Originally Posted by knc1 View Post
At the command line, enter:
mount

No you do not, removing them will not do what you wish to happen.
For the reasons why not, read my prior post.

Also, read the information about using USBnetworking then use it over USB long enough to learn what is different from using it over WiFi.
thanks Knc1, follow your hint, I found this command: mntroot rw , removed all images at screensaver folder

then, I did a test,
step 1 : only copy one image bg_ss00.png to /usr/share/blanket/screensaver/ folder , this bg_ss00.png size is 2mb,
click power button to load screensaver

step 2 : copy another image bg_ss00.png to /usr/share/blanket/screensaver/ folder, overwrite old one, this time bg_ss00.png size is 100kb, click power button to load screensaver

measued time consum of those 2 diff images loading progress, The latter is at least twice as fast as the former,
what is this mean, as I understand, cpu need read and process those images data to ram, smaller image is faster because less data need to be processe, less data less ram
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Old 05-14-2017, 08:08 PM   #4
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thanks Knc1, follow your hint, I found this command: mntroot rw , removed all images at screensaver folder

then, I did a test,
step 1 : only copy one image bg_ss00.png to /usr/share/blanket/screensaver/ folder , this bg_ss00.png size is 2mb,
click power button to load screensaver

step 2 : copy another image bg_ss00.png to /usr/share/blanket/screensaver/ folder, overwrite old one, this time bg_ss00.png size is 100kb, click power button to load screensaver

measued time consum of those 2 diff images loading progress, The latter is at least twice as fast as the former,
what is this mean, as I understand, cpu need read and process those images data to ram, smaller image is faster because less data need to be processe, less data less ram
No.
It processes the data to the frame buffer.
And that is not how a Kindle's frame buffer based display works.
The entire frame buffer memory allocation is made when the kernel starts up and never changes.
It is a fixed allocation, its size never changes because it is allocated per pixel and the number of pixels on the screen is a fixed number.

Take a look at the various run time memory stats in /proc while you test things, see what changes and what does not.

= = = =

Also, you should do as you have been advised by myself and others above!

If the job you are trying to run is being killed for using too much memory, then do what Amazon does when it runs jobs that require a lot of ram - kill the processes owned by the user named: 'framework'

If you can't do that for some reason, then do what some of our developers do when they want to run a large job (such as a long running firmware compile) -
Enable swap.
There are plenty of directions posted here on doing that.

IIRC, there is even a KUAL menu extension for using swap.

Last edited by knc1; 05-14-2017 at 08:19 PM.
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Old 05-15-2017, 01:21 AM   #5
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Quote:
Originally Posted by knc1 View Post
No.
It processes the data to the frame buffer.
And that is not how a Kindle's frame buffer based display works.
The entire frame buffer memory allocation is made when the kernel starts up and never changes.
It is a fixed allocation, its size never changes because it is allocated per pixel and the number of pixels on the screen is a fixed number.

Take a look at the various run time memory stats in /proc while you test things, see what changes and what does not.

= = = =

Also, you should do as you have been advised by myself and others above!

If the job you are trying to run is being killed for using too much memory, then do what Amazon does when it runs jobs that require a lot of ram - kill the processes owned by the user named: 'framework'

If you can't do that for some reason, then do what some of our developers do when they want to run a large job (such as a long running firmware compile) -
Enable swap.
There are plenty of directions posted here on doing that.

IIRC, there is even a KUAL menu extension for using swap.
knc1,Do not waste your time, he is a paranoid rookie
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Old 05-15-2017, 01:30 AM   #6
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my brother theft my account
is it true what he said?
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Old 05-15-2017, 08:41 AM   #7
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Quote:
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my brother theft my account
is it true what he said?
Yes.
When you ask for advice, you should also try following the advice.
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