BIOS types

[adithyay328]

Hey guys, what are the different types of BIOS, how do each of them work, and which is the most functional? Thanks in advance for your help!

[Ceatra]

UEFI and... I don't now

 

I will be right back

[Guest]

Award, Pheonix, IBM, American Megatrends, Dell, and MoBo Skinned (UEFI)

[Speedbird]

Hey guys, what are the different types of BIOS, how do each of them work, and which is the most functional? Thanks in advance for your help!

The common term is firmware, not BIOS. BIOS is a type of firmware. BIOS , or Basic Input Output System is a legacy firmware that has very limited functionality, only has the keyboard for input, has a very basic display with mostly blue, white and red colours, and can only boot from drives that are smaller than 2TB. BIOS initialises and detctects every single piece of hardware individually during startup, and does not pass the info to Windows, which has to initialise and detect everything again. BIOS uses the Master Boot Record, or MBR, for hard drives, which stores all data about the drive on the first megabyte. When BIOS loads an operating system, it reads the boot sector on the MBR to load the OS, and is unable to verify if any changes have been made to it. MBR has a limit of 4 partitions per disk, and a maximum disk size of 2TB.

UEFI, or Unified Extensible Firmware Interface, is a more modern type of firmware, which started appearing in 2012, following the requirement that all PCs with Windows 8 perinatalled need to have UEFI. UEFI has much more functionality: it supports mouse for input, it has a much better display output, allowing for nicer Setup Utlities. It can also read and write from and to FAT filesystems! UEFI also comes with a new partition table for hard disks: GUID Partition Table, or GPT. GPT supports much more partitions per disk, up to 128, and supports much larger disks. GPT also scatters partition info across the disk, instead of a single place which may get corrupted. When UEFI boots, it initialises all hardware at once, and passes that data on to the OS. Now, you are asking how does UEFI know how to boot an OS if there is no boot sector to read? Well, instead of relying on a boot sector, UEFI uses something called an UEFI System Partition, or ESP. ESP is a small partition on the hard drive, formatted in FAT32, and it contains the boot files for the OS. How does UEFI know how to load it you ask? Well, UEFI has some basic application support, and that is mostly used by OS boot managers. The boot manager is always stored in the ESP, in the folder \EFI\boot\. Its filename is boot<pctype>.efi. For a 64-bit PC it is bootx64.efi. By using that, the UEFI can also verify that the bootloader hasn't been tampered with. This is called Secure Boot, and it verifies the signature of the boot file against a trusted one. If it isn't trusted, or isn't signed, the UEFI can refuse boot.

[adithyay328]

The common term is firmware, not BIOS. BIOS is a type of firmware. BIOS , or Basic Input Output System is a legacy firmware that has very limited functionality, only has the keyboard for input, has a very basic display with mostly blue, white and red colours, and can only boot from drives that are smaller than 2TB. BIOS initialises and detctects every single piece of hardware individually during startup, and does not pass the info to Windows, which has to initialise and detect everything again. BIOS uses the Master Boot Record, or MBR, for hard drives, which stores all data about the drive on the first megabyte. When BIOS loads an operating system, it reads the boot sector on the MBR to load the OS, and is unable to verify if any changes have been made to it. MBR has a limit of 4 partitions per disk, and a maximum disk size of 2TB.

UEFI, or Unified Extensible Firmware Interface, is a more modern type of firmware, which started appearing in 2012, following the requirement that all PCs with Windows 8 perinatalled need to have UEFI. UEFI has much more functionality: it supports mouse for input, it has a much better display output, allowing for nicer Setup Utlities. It can also read and write from and to FAT filesystems! UEFI also comes with a new partition table for hard disks: GUID Partition Table, or GPT. GPT supports much more partitions per disk, up to 128, and supports much larger disks. GPT also scatters partition info across the disk, instead of a single place which may get corrupted. When UEFI boots, it initialises all hardware at once, and passes that data on to the OS. Now, you are asking how does UEFI know how to boot an OS if there is no boot sector to read? Well, instead of relying on a boot sector, UEFI uses something called an UEFI System Partition, or ESP. ESP is a small partition on the hard drive, formatted in FAT32, and it contains the boot files for the OS. How does UEFI know how to load it you ask? Well, UEFI has some basic application support, and that is mostly used by OS boot managers. The boot manager is always stored in the ESP, in the folder \EFI\boot\. Its filename is boot<pctype>.efi. For a 64-bit PC it is bootx64.efi. By using that, the UEFI can also verify that the bootloader hasn't been tampered with. This is called Secure Boot, and it verifies the signature of the boot file against a trusted one. If it isn't trusted, or isn't signed, the UEFI can refuse boot.

Is there a type of firmware which you can control via an app on your PC, or is it all before windows loads up, in the boot loader?

[LogicalDrm]

Is there a type of firmware which you can control via an app on your PC, or is it all before windows loads up, in the boot loader?

What are you trying to do?

I tend to think that as simplest, both BIOS and UEFI are just different UI versions. And their look and options vary depending on mobo features and manufacturer.

As for my knowledge only some OC software change BIOS / UEFI settings in windows.

[DEDRICK]

Is there a type of firmware which you can control via an app on your PC, or is it all before windows loads up, in the boot loader?

 

You have been able to modify CPU overclocking and FAN settings in Windows for many years with applications supplied by the motherboard maker/other means.  Most stuff is limited to BIOS only though