3:37 Wrong, BIOS does not care whether you have an MBR, it just checks that the bytes 511&512 == 0xaa55, loads the first sector (512 bytes) of such disk into memory at 0x7c00, and jumps to it in real (16 bit) mode. Such a sector is then called a boot sector. MBR then is a specific type of a boot sector that contains a partition scheme; UEFI emulating BIOS (CSM) actually *does* check for an MBR, but BIOS does *not* (well, some might, BIOS is not standardized)
8:20 No, it will load the *init*, systemd being one of many. systemd is the most popular, but there's other very popular options, such as runit, openrc, s6, or for embedded system, busybox init or just a shell.
SystemD is from a different era than BIOS - BIOS is early 2000s, SystemD is late 2010s. SysVinit is the init for the BIOS era. Mixing them like this looks quite funny. That's like saying that modern cars have to be first started with a crank and then you connect your smartphone to the bluetooth audio system.
The BIOS reads each indicated MDR and checks if it contains a valid MBR which is not 512 bytes but is usually just the beginning of a chain of events. 512 bytes is the size adopted for the sector in this system, so the basic size of the MDR, and what this size contains is another matter..
Hi any tutorial or link how I can put the Systemd onto a Windows 11 Installer Flashdrive using Windows or even better using maOS? Thank you, God bless you.
heres what the ai thinks: Sure! Here’s a more detailed breakdown: 1. BIOS/UEFI: • It powers on the hardware and performs the POST to check hardware integrity. • It then looks for a bootable device based on the boot order settings. • It loads the bootloader from the Master Boot Record (MBR) or the GUID Partition Table (GPT) on the bootable device. 2. Bootloader (e.g., GRUB): • Displays a menu to select which kernel or operating system to boot. • It can also allow parameters to be passed to the kernel. • Once a selection is made, it loads the chosen kernel into memory. 3. Kernel Initialization: • The kernel initializes and configures memory and hardware with the necessary drivers. 4. initramfs: • Loaded immediately after the kernel if present, typically embedded within the kernel image or as a separate file. • Provides a temporary root filesystem in RAM, containing necessary drivers and utilities to support the kernel in mounting the real root filesystem. • Executes an init script which usually detects and mounts the real root filesystem. 5. Switch Root: • The init in initramfs mounts the real root filesystem and then switches to it, moving the root of the filesystem from the initramfs in RAM to the actual disk. • initramfs is then cleared from RAM. 6. Init Process: • The kernel executes the /sbin/init program (can be systemd, Upstart, or another init system) on the real root filesystem. • This is the first process started by the kernel in the user space. 7. Runlevel/Target Services: • The init system configures services and scripts to run at various runlevels or targets. • This includes services like network settings, graphical interfaces, and user logins. 8. User Login: • The system finishes booting up and reaches a login prompt or graphical login screen, making it ready for user interaction. This process covers the essentials from hardware power-up to the user login phase, integrating various components crucial for system operation.
Thank you so much for helping me understand the boot process a lot better. I am currently taking the Ucertify Red Hat preparation course to get my Red Hat certification. You made a lot more clear for me🤙🤙
I'm confused. I'm trying to multiboot several linux distros and when I looked up PopOS Grub, many people said something to the effect of PopOS doesn't use Grub it uses SystemD. Would the PopOS flowchart be different? Also thanks for the video!
You're omitting the need for a BOOT flag on the right partition.
2 หลายเดือนก่อน
While I understand that I'm bringing algorithm attention to the video even if my comment is negative and most information is accurate even though lacking and confusing... What a poop nugget! When compared to works from independent creators here on TH-cam. To think this was a payed course is outrageous. This should be taken down and made do the "walk of atonement".
Now I have to watch the video a second time but this time I am going to pay attention to what he is saying as opposed to how he is saying it!
Annoying pronunciation and accent. I don't know how CBT allowed this
@@djdelevic hey oi loov 'im!
@@djdelevic Scottish accents are so much nicer to listen to them American accents tbh
3:37 Wrong, BIOS does not care whether you have an MBR, it just checks that the bytes 511&512 == 0xaa55, loads the first sector (512 bytes) of such disk into memory at 0x7c00, and jumps to it in real (16 bit) mode. Such a sector is then called a boot sector. MBR then is a specific type of a boot sector that contains a partition scheme; UEFI emulating BIOS (CSM) actually *does* check for an MBR, but BIOS does *not* (well, some might, BIOS is not standardized)
"WRONG" okay big dawg
8:20 No, it will load the *init*, systemd being one of many. systemd is the most popular, but there's other very popular options, such as runit, openrc, s6, or for embedded system, busybox init or just a shell.
SystemD is from a different era than BIOS - BIOS is early 2000s, SystemD is late 2010s. SysVinit is the init for the BIOS era. Mixing them like this looks quite funny. That's like saying that modern cars have to be first started with a crank and then you connect your smartphone to the bluetooth audio system.
The BIOS reads each indicated MDR and checks if it contains a valid MBR which is not 512 bytes but is usually just the beginning of a chain of events. 512 bytes is the size adopted for the sector in this system, so the basic size of the MDR, and what this size contains is another matter..
Great explanation! Thank you
Hi any tutorial or link how I can put the Systemd onto a Windows 11 Installer Flashdrive using Windows or even better using maOS?
Thank you, God bless you.
Where did initrm go?
how it differ if we use UEFI?
uefi provides with a much interactive GUI and can work with a storage of larger than what BIOS can support(which I think is 2TB)
One key difference: UEFI systems boot .efi executables. E.g. /boot/EFI/GRUB/grubx64.efi for GRUB2
Absolutely great video! Makes it very easy to understand.
Love from South Africa
How GRUB can read /boot files if you have not mounted / ?
correct me if im wrong but the kernel, initramfs and grub are stored in a firesystem that is above the / directory.
heres what the ai thinks:
Sure! Here’s a more detailed breakdown:
1. BIOS/UEFI:
• It powers on the hardware and performs the POST to check hardware integrity.
• It then looks for a bootable device based on the boot order settings.
• It loads the bootloader from the Master Boot Record (MBR) or the GUID Partition Table (GPT) on the bootable device.
2. Bootloader (e.g., GRUB):
• Displays a menu to select which kernel or operating system to boot.
• It can also allow parameters to be passed to the kernel.
• Once a selection is made, it loads the chosen kernel into memory.
3. Kernel Initialization:
• The kernel initializes and configures memory and hardware with the necessary drivers.
4. initramfs:
• Loaded immediately after the kernel if present, typically embedded within the kernel image or as a separate file.
• Provides a temporary root filesystem in RAM, containing necessary drivers and utilities to support the kernel in mounting the real root filesystem.
• Executes an init script which usually detects and mounts the real root filesystem.
5. Switch Root:
• The init in initramfs mounts the real root filesystem and then switches to it, moving the root of the filesystem from the initramfs in RAM to the actual disk.
• initramfs is then cleared from RAM.
6. Init Process:
• The kernel executes the /sbin/init program (can be systemd, Upstart, or another init system) on the real root filesystem.
• This is the first process started by the kernel in the user space.
7. Runlevel/Target Services:
• The init system configures services and scripts to run at various runlevels or targets.
• This includes services like network settings, graphical interfaces, and user logins.
8. User Login:
• The system finishes booting up and reaches a login prompt or graphical login screen, making it ready for user interaction.
This process covers the essentials from hardware power-up to the user login phase, integrating various components crucial for system operation.
Thank you so much for helping me understand the boot process a lot better. I am currently taking the Ucertify Red Hat preparation course to get my Red Hat certification. You made a lot more clear for me🤙🤙
I'm confused. I'm trying to multiboot several linux distros and when I looked up PopOS Grub, many people said something to the effect of PopOS doesn't use Grub it uses SystemD. Would the PopOS flowchart be different?
Also thanks for the video!
I don't think systemd is related to grub, but I also don't know what I'm talking about
@clonkex 😂😂😂
Very very easy to understand. Thank you
Love the LPIC-1 tutorial you have =) thank you!!! would have been good if CBT Nuggets had windows app available though
Thank you for the video really enjoyed it please post more on lpic 1
Is it correct to say that for PXE boot the GRUB2 bootloader is replaced with NBP?
Love this accent. Awesome. I love the way he says “Integrity Test”.
This was really nice informative and knowledgeable helpful video
Great info! Just wish I had ears better able to understand the info by sorting out Mr. McGovern's accent. That's all on me, though. Thanks!!!
excellent video 🎉
1:08 are we living in the early 2000s? The Windows XP era? Linux 2.6?
Thanks
Thank you
7:24 the operating system has total control over the operating system...? Wat
UEFI, GPT, systemd-boot? This seems dated.
It's not possible to explain the Linux boot process, it changes it's mind what it produces boot to boot.
This is 10 years out of date. There is no BIOS anymore.
You're omitting the need for a BOOT flag on the right partition.
While I understand that I'm bringing algorithm attention to the video even if my comment is negative and most information is accurate even though lacking and confusing... What a poop nugget! When compared to works from independent creators here on TH-cam. To think this was a payed course is outrageous. This should be taken down and made do the "walk of atonement".