Linux Programming

26-May-22 5:35

I am looking for someone who is very familiar with the subject.
Running Ubuntu 21.xx and I am unable to activate this feature ever since I switched to 21.xx.
My initial grub menu contains several OS , I managed to option " no flash " and get nice "progress report " during boot. I just cannot option "run last active OS" - no asterisk (*) in base grub menu..
When I do "update grub" the OS identified DO NOT match the main boot menu.

Please do not waste your time with "RTFM" or "it runs fine for me".

Ask for clarification instead if you do not get it.

Any real help would be greatly appreciated.

PS. This is boot problem, hence NO "cut / copy/ screen shot / paste " is not available - do not ask for photo.

Richard MacCutchan26-May-22 21:46

26-May-22 21:46

Have you tried the suggestions in this answer: dual boot - How to get grub2 to remember last choice? - Ask Ubuntu[^] ?

Member 1496877127-May-22 6:50

27-May-22 6:50

I have checked the grub file many times - here is my current copy .
and this is my "save last used ' option

GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true

I have been checking the validity of my grub using this option

#GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

it works as expected.

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'
GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true
#GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
#GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

Richard MacCutchan27-May-22 21:53

27-May-22 21:53

According to my reading of the documentation that should work, so I am afraid I have no more ideas.

Gerry Schmitz27-May-22 8:06

Gerry Schmitz

27-May-22 8:06

You may or may not have access to a GRUB environment block (of which you make no mention).

Quote:
For safety reasons, this storage is only available when installed on a plain disk (no LVM or RAID), using a non-checksumming filesystem (no ZFS), and using BIOS or EFI functions (no ATA, USB or IEEE1275).

grub-mkconfig uses this facility to implement ‘GRUB_SAVEDEFAULT’ (see Simple configuration).

GNU GRUB Manual 2.06

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

Member 1496877128-May-22 6:46

28-May-22 6:46

I have a copy of "dmesg" , presumably "boot process " log.
Is there a way to identify actual "grub" file used ?
I am still puzzled why I am receiving the boot messages AFTER I
uncommented "splash" option.

Gerry Schmitz28-May-22 7:47

Gerry Schmitz

28-May-22 7:47

Quote:
The environment block is a preallocated 1024-byte file, which normally lives in /boot/grub/grubenv (although you should not assume this). At boot time, the load_env command (see load_env) loads environment variables from it, and the save_env (see save_env) command saves environment variables to it. From a running system, the grub-editenv utility can be used to edit the environment block.

GNU GRUB Manual 2.06: Environment block

Member 1496877129-May-22 7:44

Running file properties...

29-May-22 7:44

SOLVED?
The UEFI setup has an option "F11" - boot menu, it brings up grub menu. This menu, I call it "short version ", differs from what I have been using . And it matches output of "update-grub". After using it once I now have the " run last OS used" working. After boot I get this "short version" - with an asterisk indication of last OS used.

I did suspect UEFI from the start...which grub is actually used, optioned ???

BUT I have never updated UEFI and I am NOT going to risk more problems - so I'll leave it alone.

PS With "last OS used" working I no longer have "splash " disabled , no boot progress , - go figure...

Member 1496877130-Apr-22 4:25

30-Apr-22 4:25

For those who do not know - I am not welcomed to ask questions in Ubuntu forum...
( asked too many questions )

Using Ubuntu 21.10 and having this annoying problem
In "file manager" when asking for file "properties" I get two responses
1. Immediate display of current usage of hardware - that is what i wanted
2. File manager takes off and starts "scanning" all files, takes long time and really does not
provide simple information about how much (%) is in use on specific hardware...

Where is the resolution to this?
Is there an "properties" option I am missing ?

Richard MacCutchan30-Apr-22 5:07

30-Apr-22 5:07

I just tried this and it works correctly. Whatever is happening on your system is unique to you, and may have something to do with previous questions which suggest that your installation is not very stable.

trønderen30-Apr-22 8:30

trønderen

30-Apr-22 8:30

Isn't this something you can see from the source code?

That's the the great advantage of open source projects: If the system doesn't behave the way you want it to, you have the full freedom to go into the source code and modify it the way you want.

Member 149687711-May-22 15:15

1-May-22 15:15

As a "user" why should I (have) to do that ?
It used to work just fine - giving a hardware usage in % ...
Now it ..... as posted.

Thanks for reply.

trønderen2-May-22 1:58

trønderen

2-May-22 1:58

Member 14968771 wrote:
As a "user" why should I (have) to do that ?

Because it is Free and Open Source Software.

It is given to you so that you can fix it yourself. That is what the free-ness and open-ness is about. You may of course ask your friends to fix it for you, or even pay someone to fix it (although that sort of kills the "free" idea, at least in the sense of "free beer").

When you accept a "free" offer that is financed by ads and commercials, then you are the product being sold.
When you accept "free" and open sources software, then you are the maintainer of that software.

This is 101 FOSS.

Member 149687712-May-22 5:51

How to actually install Qwt

2-May-22 5:51

How do you react to this :
run OS update - manually or automatically and after reboot get
'... OS is experienced internal error... (send us this message ) "

If you say " what do you expect for free " this discussions is over.

Member 1496877122-Apr-22 6:47

How to correlate hci_tool commands with "blueZ" library functions ?

22-Apr-22 6:47

I am not allowed to post on Linux site, so I am posting here.

I have never done this so I am confused with these instructions.
I like to install the Qwt library "under" my Qt folder.
I am using QtCreator so my qmake is current and working, so I skipped verifying qmake.
qwt-6.2.0 folder did not exist on my system so I did
cd Qt
mkdir qwt-6.2.0

then I get lost what to do next...
this folder obviously does not exists in /Qt folder

/usr/local/Qt-5.0.1/bin/qmake qwt.pro

Unix-like systems
The first step before creating the Makefile is to check that the correct version of qmake is used. F.e. on older Linux distribution you often find a Qt3 qmake and in the path.
The default setting of qmake is to generate a makefile that builds Qwt for the same environment where the version of qmake has been built for. So creating a makefile usually means something like:
cd qwt-6.2.0
/usr/local/Qt-5.0.1/bin/qmake qwt.pro
The generated Makefile includes all paths related to the chosen Qt version and the next step is:
make
( On multicore systems you can speed up building the Qwt libraries with running several jobs simultaneously: f.e. "make -j4" on a dual core. )
Finally you have to install everything below the directories you have specified in qwtconfig.pri. Usually this is one of the system directories ( /usr/local, /opt, ... ) where you don't have write permission and then the installation needs to be done as root:
sudo make install
( On systems where sudo is not supported you can do the same with: su -c "make install" )

Member 1496877124-Mar-22 14:01

Re: How to correlate hci_tool commands with "blueZ" library functions ?

24-Mar-22 14:01

hci_tool "commands " are derived from "blueZ" library.
Using hci_tool commands in C/C++ (source )code is ....
The hci_tool scan command is implemented in "blueZ" as hci_inquire....

hci_tool --help give a nice overview of all the command options.

Is there a real (written) resource to "translate" hci_tool commands to "blueZ" library functions ?

OK - I found hci_lib.h where all the (function) declarations are...

Now if I can get FUNCTION DESCRIPTIONS I will be closer to "best guess" how hcitool commands and bluez function relate. Is there such documentation anywhere ?

It is NOT in "blueZ" on github .
?

modified 25-Mar-22 0:38am.

Richard MacCutchan24-Mar-22 21:53

Re: How to correlate hci_tool commands with "blueZ" library functions ?

24-Mar-22 21:53

If there is no documentation that describes the functions and their usage, then the only way to find out is by looking at the source code if it is available anywhere. Try https://android.googlesource.com/platform/external/bluetooth/bluez/+/froyo-release/lib/hci.c[^] for a start.

Member 1496877125-Mar-22 3:49

Re: How to correlate hci_tool commands with "blueZ" library functions ?

25-Mar-22 3:49

Thanks - that is what I am using. It is odd there is no documentation.
Most functions use same or similar variables , but...

for example "device_desc" and "dd" are same...

This "open" concept is not that open - somehow "job security" comes to mind instead...

Perhaps "Most commonly used variable names dictionary (u-tube) " is overdue.

int i = index of something...
int error = error number ( duh )

Have a great day

Richard MacCutchan25-Mar-22 3:52

How to find what name and where the (bluetooth) library is located?

25-Mar-22 3:52

Member 14968771 wrote:
for example "device_desc" and "dd" are same...

Maybe, but that is not a rule that you can rely on.

Member 1496877120-Mar-22 8:41