CODEWITHSUNDEEP
cassemblylinux-kernelbiosreal-mode
manav m-n
manav m-n

Reputation: 11394

Loading the Linux OS Kernel from BIOS

From book: After power-on, the CPU load the BIOS, build the interrupt vector table, and start interrupt service routines in real address mode. By BIOS, the CPU receives INT 0x19. The ISR of INT 0x19 loads the first sector (512B) into the memory. This sector is the boot part of Linux which loads other parts of the OS into the memory.

The first sector is bootsect.s, which is written in assembly. It is the first system code that is loaded into the memory. I doubt whether assembly instructions are loaded or compiled machine instructions are loaded into memory. Does BIOS have a native assembler to convert assembly to machine instructions?

Upvotes: 0

Views: 367

Answers (2)

Martin James
Martin James

Reputation: 24907

NO. It's binary instruction codes that are loaded to memory and then executed directly.

Upvotes: 0

i486
i486

Reputation: 6572

Of course, the loaded sector contains compiled machine language instructions - not assembly source (.asm).

Upvotes: 1

Related Questions