bootloader question

[rookie1010]

Hello

does the bootloader also loads the kernel, or in case of XIP it just jumps to the location, is that correct?

 

[Atheus]

A stage 1 bootloader is a very small and simple thing which just tells the machine where to load the next stage. Some older OSs got away with just loading the kernel from stage 1, but these days it loads a second stage (NTLDR, GRUB stage 2, etc) which is larger, and does other things like give you a menu from which to choose the kernel you want to load.

 

[rookie1010]

thanks for the reply

does a stage2 also just load the kernel but it gives you a few more options as to where to load the kernel form ?

 

[Atheus]

Pretty much.

I'm sure a modern stage 2 loader could do other things like checksum on the kernel to prevent errors, but I don't know if they do of not, I've never had to write one or anything.

 

[rookie1010]

thanks for the reply dude

 

[Smilin]

Originally posted by: rookie1010
Hello

does the bootloader also loads the kernel, or in case of XIP it just jumps to the location, is that correct?

bios runs, loads the MBR, checks partition table for active partition, goes there, loads boot sector, (NT) boot sector loads ntldr, ntldr reads boot.ini, locates ntoskrnl.exe, ntoskrnl loads start 0 services, subsystems, smss, winlogon, winlogon loads userinit, loads explorer, tada desktop.

I'm getting rusty, I think I missed one or two in the later kernel phase.