3.13 Booting and Transition to Active OS

• ⭐️ Name of process: POST

• ⭐️ Peripherals wake up before the HD

• 3-2: picture of msinfo32 questions about the architecture
• 3-3: can you have 64bit OS on x86? NO
• 3-4: minimum and recommended, if you have multitasking OS, does it make sense with one core, one thread? NO.
• 3-5: not in exam!!!!
• 3-6: CPU-Z memorize the portions
• 3-7: which is the name of the application that you want to create a bootable USB for microsoft? which is the name of the application that you want to do unattended install for windows?
• 3-8: diff portions of a disk, sector, cluter, type of partitions, format of partitions, concept of volume, SSD is not on exam
• look at disk manager and questions about partitions
• can you reach partition D? Depends on your BIOS, bc with legacy, you can reach only the first four partitions
• 3-9: diff about MBR, GPT
• 3-10: diff of Legacy and UEFI
• concept about boot sequence, HD comes first, then network then external
• 3-11: compatibility, if you have windows numbers or vista…
• 3-12: tunneling, dual booting
• 3-13: order of POST: first CPU, then RAM, then HD…

1️⃣ BIOS

• recieves electricity with ATX-P1

• ATX-P1 is the cable that provides electricity to the motherboard

• BIOS has a firmware printed

2️⃣ POST

• Power On Self Test
• process launched by the BIOS

• process for saying "computer! wake up!"

• when the firmware on the BIOS is executed, starts the POST process
• the POST is not saved on the RAM ❌

• process that starts when the BIOS starts

• ➡️ POST wakes up the computer

✔️ The order that POST wakes up the computer

• (1) CPU: first wake up the brain
• (2) RAM: second wake up the body
  • if the RAM is incorrect, there will be three long beeps
• (3) Peripherals: to show error messages

• (4) Harddisk

  • Inside the harddisk, again there are orders

  • (5) Bootstrap loader, GRUB, the menus: these are not related to the partitions ❌

  • (6) Index:
    • if you are in MBR, MBR table
    • if you are in GPT, MBR protective(the 4 first Primary, this is very important for legacy)
    • But if you are using UEFI, you will not use MBR protective
    • if you have an error in the index, this is also not related to the partitions ❌
  • (7) Big index:
    • the GPT partitions table for GPT
    • if there is an error in index, you will have another index error 2
  • (8) the active partition and (9) the booting partition of the selected partition boots
    • only the selected partition boots
    • not all the partitions boot
    • also, including the booting partition of the selected partition
    • if there is an error in booting windows, do not reformat :c , /
    • but reformat the /boot or EFI
    • if there is an error is in the kernel :c or /
    • then reformat the kernel
  • (10) When everything is ok….
• 💡 Note 1:
• GRUB errors are not related to partitions
• GRUB errors mean rebuild the menu
• so, when you see a GRUB error, do not format your HD!
• 💡 Note 2:
• Index errors are also not related to partitions
• so, do not format, do not change structure of the partitions
• 💡 Note 3:
• if there is an error in booting windows, do not reformat :c or /
• but reformat the /boot or EFI
• 💡 Note 4:
• if there is an error is in the kernel :c or /
• then reformat the kernel

3️⃣ When everything is OK, OS starts to boot….

• (1) Dispatcher
  • manages FIFO, RR…
• (2) Memory manager
  • segmentation, paging…
• (3) Interruptions manager
  • interruptions in the RAM
• (4) Tools for manaing the HD
  • the DEFRAG tool

✅ Use GPartEd

• use GPartEd to create partitions

1️⃣ Download GPartEd

• stable versions are for normal users, compatible for all architectures

• 👎🏻 however, might not be complete, very general

• as a systems expert, use the specific version for the architecture you have
• you can check the architecture of your computer with msinfo32
• and you download the version according to it
• if you have x64, download the amd64.iso
• amd64 means that the version is optimized for amd micro processors, but compatible with intel
• but i686 might be optimized for intel, but not compatible with amd

2️⃣ Create a bootable USB

• now you have gparted.iso in your downloads folder
• you have two choices
• 1️⃣ if you have a real computer: create a bootable USB

• 2️⃣ if you have a VM: add the .iso to the VM

• 1️⃣ create a bootable USB: if you have a real computer
• to make a bootable USB, you cannot use the normal tools like Rufus, UUI, Lili, Mediacreation, Ventoy

• you should use specific tool Real GPartEd USB creator

• 2️⃣ add the .iso to the VM

✅ Rufus, UUI, Mediacreation, Ventoy

• Rufus is widely used
• UUI2 works very stable