Truly silent boot with grub2

[pieric]

Hi,

I'm trying to achive a silent boot with (close to) no output until c server has started.
Getting rid of most messages worked by adding kernel commnd to redirect console output to /dev/null.

However some messages remained - see attached image. Not sure if they are grub related...

Anybody who can give me a hint to hide them?

Many thanks in advance!
Eric

[curaga]

I think the first line is from your bootloader, and others from the kernel's early booting code. The "earlycon" bootcode in kernel-parameters.txt looks relevant, but I'm not sure if there's a supported way to disable it. Could be you'd need to edit kernel code to shut that up.

[pieric]

Indeed, kernel customization was necessary. I found some hints on google.

Here are the steps I did to get a sleek boot (no debug info though):

Code: [Select]

# Download Packages ----------------------------------------------------------------------------
    tce-load -w compiletc perl5 bash ncursesw-dev bc advcomp glibc_apps

# Load Packages --------------------------------------------------------------------------------
    tce-load -i compiletc perl5 bash ncursesw-dev bc advcomp glibc_apps
   
# Go root --------------------------------------------------------------------------------------
    sudo su
   
# Create working dir ---------------------------------------------------------------------------
    mkdir /usr/src ; cd /usr/src

# Get kernel sources ---------------------------------------------------------------------------   
    wget repo.tinycorelinux.net/11.x/x86/release/src/kernel/config-5.4.3-tinycore
    wget repo.tinycorelinux.net/11.x/x86/release/src/kernel/linux-5.4.3-patched.txz
   
# Uncompress source ---------------------------------------------------------------------------
    tar Jxvf linux-5.4.3-patched.txz

# Configure -----------------------------------------------------------------------------------
    cd cd /usr/src/linux-5.4.3
    make mrproper
    cp ../config-5.4.3-tinycore .config
    make oldconfig
    make menuconfig
   
#        -> To remove early boot messages
#           https://www.refining-linux.org/archives/4-Boot-your-Linux-silently.html
#            Remove flags here: 
#                Kernel hacking --->
#                [ ] Enable verbose x86 bootup info messages
#                [ ] Early printk
#        -> Optinally Reduce loglevel for "quiet" argument from "4" to "3"
       
# Compile and copy -----------------------------------------------------------------------------
    make bzImage
    cp /usr/src/linux-5.4.3/arch/x86/boot/bzImage /mnt/sda1/boot/vmlinuz.new

My grub.cfg with "vt.global_cursor_default=0" to get rid of blinking cursor

Code: [Select]

insmod ext2
set default=0
set timeout=0
set timeout_style=hidden
search --no-floppy --fs-uuid --set=root 9f6a5bac-eb18-41bd-8c87-68ad5741d4b5                         
menuentry "tiny" {
    linux /boot/vmlinuz.mod quiet console=/dev/null vt.global_cursor_default=0
    initrd /boot/core.gz
}