I was wondering if a bootloader was specific to the device you are booting on?
For exemple if a usb bootloader to install windows is exactly the same as a cd bootloader to install windows or if it is device specific?
My guess is it the same because in either case the bios loads the first 512 bytes (of the first block of the device) into memory and if the machine code is compatible with the cpu the data will be processed the same!
But i'm unsure! Any answer welcomed! Thanks!
It depends on what you mean by "device you are booting on". If you are referring to your storage device, there is nothing specific to it in the first stage of the boot process. (AHCI specific driver stuff is part of a later stage).
If you consider the (UEFI)-BIOS as a device, it is device specific because a UEFI boot process is different from a legacy BIOS boot process.
My guess is it the same because in either case the bios loads the first 512 bytes (of the first block of the device) into memory and if the machine code is compatible with the cpu the data will be processed the same!
This assumption holds true until UEFI-BIOS was introduced. On a modern UEFI-BIOS this is a kind of rarely occuring boot setting that is only used to circumvent certain boot problems.
This becomes obvious if you compare the size of the file "bootmgr.efi" to the code stored in the master boot record.
You can't put the code in the master boot record into the file "bootmgr.efi" and expect it to boot a UEFI machine.
The article referred to in another answer to your question
https://en.wikipedia.org/wiki/Bootloader
is outdated because it does not take into account the different boot process when a UEFI-BIOS is booting in UEFI mode. (An UEFI-BIOS can boot the old way when it contains a so-called CSM (compatibility support module).
No, a bootloader is not specific to the device it is booting on.
During the boot process, and until the operating system is loaded and takes over, the bootloader uses functions that are published by the BIOS.
In other words, the BIOS is specific to the device, not the initial bootloader. Note that bootloaders may be chained, but that subject is too complex to detail here.
For more information, see Wikipedia Bootloader.
