3.10 BIOS Legacy vs. UEFI

BIOS Legacy 🆚 BIOS UEFI

BIOS: Basic Input Output System

• to study the BIOS, we use VM
• bc if we just change the BIOS, we will not be able to show anything
• your computer will be booting

🆚 BIOS Legacy

1️⃣ Does not have a GUI ❌

• no Graphic User Interface
• sometime you need to use the keyboard, you cannot use the mouse
• 👎🏻 not very user frienly
• 👎🏻 sometimes complicated

2️⃣ Stable BIOS

• 👍🏻 But as Bios Legacy has a long history, it is well tested, robust

3️⃣ Firmware

• Bios Legacy is a firmware
• firmware: very basic software very attatched to hardware, already installed on the hardware that boots automatically

4️⃣ EPROM

• Bios Legacy is a EPROM: Electronically Programmable Read Only Memory
• Electronically Programmable: we print 0 and 1 inside the chip
• when you buy, the information is already inside
• so it is not updateable ❌
• Read Only: you can only read from BIOS Legacy

💡 Dual BIOS

• (⭐️ text question)
• Bios Legacy: Dual BIOS
• Dual BIOS: some computers have two chips, two BIOS
• and in one of them, keeps the factory settings
• In this case, updates could be possible

• and you can always format it

• So Dual BIOS is perfect for system professionals
• so they can always try several things,
• and if their computer breaks down,

• they can always go back/default

• some DUAL legacy BIOS might have extension for overclocking
• but only if they are dual

🆚 BIOS UEFI

Unified Extensible Firmware Interface

• Unify: global, structure of UEFI is the same world-wide
• Extensible: you can update it
• Firmware
• Interface

1️⃣ UEFI has GUI ⭕️

• has Graphic user interface
• user friendly
• visual controls
• you can use keyboard, mouse…

2️⃣ Downloadable in a USB

• If the chip dies
• you can download the firmware from the internet,
• put it in the USB
• then install it again
• but the USB will always have to be plugged in, so some computers put tape on the USB to stick to the computer

3️⃣ Fast Booting

• (⭐️ text question)
• If you have UEFI
• you can activate fast booting
• Fast booting: switch the computer on, without doing much tests/reviews
• just swtich the computer on, leave the test/review for later
• 👎🏻 some applications do not support fast booting, they cannot start with fast booting
• ➡️ so you might have to deactivate fast booting

4️⃣ Secure Booting

• (⭐️ text question)
• Secure Booting: only certified applications boot
• certified 🟰 signed 🟰 with a copy right
• 👍🏻 improve security
• 👎🏻 not all applications are certified
• for example, linux is not certified
• ➡️ so if you want a linux, you should deactivate secure booting

5️⃣ UEFI is a Third-Party Extensions

• first-party in a computer/system: user
• second-party in a computer/system: OS
• third-party in a computer: other companies
• so UEFI can have extensions from other companies, different from the manufacture
• 👀 overclocking
  • artificially increasing the clock speed of your computer
  • 👎🏻 risky, imagine your heart running faster!
  • you need extra refrigeration, need a better fan
  • 👍🏻 it can increase the speed of your computer
  • overclocking can be done with UEFI
  • by downloading applications from other companies
  • used for video games with VR

6️⃣ UEFI is not that robust

• has a shorter history than BIOS Legacy
• so not so much testing has been done
• Legacy has been here for 50 years, whereas UEFI has a history of 14~15 years

✅ Functions of BIOS

• both Legacy and UEFI

☑️ Four most important functions of the BIOS

1️⃣ Change the Boot sequence of a computer

• By default, the order of booting is as following

  • (1) Harddisk: the computer looks for the OS in the HD
  • (2) Network: the computer can also search for OS through the network
  • (3) External memory: the computer looks for OS in the USB
• ☹️ The problem of the default order
• imagine you have windows 7, but you want to update to windows 10
• you download the iso file of the windows 10
• then you put the iso file inside the bootable USB

• in order put the iso file in the USB, use programs such as RUFUS, UUI, LiLi, VENTOY, MediaCreationTool

• After you introduce the USB
• but if you do not alter the boot sequence,
• your computer will always start with OS in the harddisk, which is windows 7
• ➡️ you need to enter the BIOS and set the USB as the first OS to boot
• ➡️ place USB before the HD

• then the computer will boot the OS in the USB first, so it will boot windows 10

• Then you can choose
• for the USB to override the HD
• or can create a dual booting system

2️⃣ Activate or deactivate the POST

• POST: Power On Self Test
• way of booting a computer making sure that all the componenets are perfect
• go component by component to check if it is ok
• 👎🏻 very slow, as you need to check all the components

3️⃣ Create RAID systems(distributed storage)

• RAID: Redundant Array of Independent Disks
• to have several harddisks interconnected
• one information is split among the HD
• write the information in none of the HD at the same time
• information is mixed among the several disks

4️⃣ Activate or deactivate Virtualization(Virtual Machine)

• If you can work with VMs or not
• some BIOSs bring the VM deactivated
• then VMs will not work
• you need to activate the VM

✅ How to know if I have Legecy or UEFI?

Win+R > MSINFO32 > Modo BIOS

• modo de bios:
• you can also see the brand and the date of the BIOS
• with this you can check the bday of the computer
• MSINFO32 was also used to see 32/64

✅ How do you enter your BIOS?

1️⃣ How to enter BIOS 1

• when the computer is OFF
• switch the computer on

• then press Esc, Supr, F1, F2, F10, F12

  • ❓ why so many options: depends on the brand of the BIOS
• need to press the keys super fast, many many times
• before the active OS appears

• if the windows(active OS) start appearing, you are too late

• In laptops, if the key for entering your BIOS is F1, F2, F10, F12
• then you need to press it with the Fn key

2️⃣ How to enter BIOS 2

• when you cannot switch your computer off
• when you are inside windows 10/11
• ⚠️ this technique is only valid if you have a UEFI

3️⃣ What happens if we cannot access the BIOS?

• Why I cannot access the BIOS?
• (1) bc you have fast start activated
• you do not have time to press the keys
• 💊 deactivate the fast boot

• Why I cannot access the BIOS?
• (2) Sometimes your BIOS needs an emergency USB
• bc the BIOS is corrupted

4️⃣

• 1️⃣
• 2️⃣
• 3️⃣
• 4️⃣ 👍🏻 👎🏻

⭐️⭐️⭐️ EXAM ⭐️⭐️⭐️
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