Does a normal PC (the BIOS) do any checks of MBR, boot sector and boot files at boot time? Are there any checksums ? Are there differences between FAT-12, FAT-16, FAT-32 and NTFS? Juergen
Any check of MBR, Boot Sector a.s.o. at boot time?
Sep 06, 2004
2 Replies
files
The boot sector is loaded by the BIOS. The BIOS does not know about file systems (FAT, NTFS etc). The code in the boot sector is responsible for loading the rest of the bootloader and knows about the file system on the disc. Yes there are checks to prevent the BIOS loading and executing garbage.
Regards Sergio Masci
formatting link
- optimising PIC compiler
Not much of a check, though - just looking for two bytes set to a magic value! The BIOS _ALSO_ knows nothing of the MBR structure except for those two blessed bytes that indicate a "bootable" disk.
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