Re: How does linux boot - best way 2 figure it out
On Fri, 22 Oct 2004, Ritesh Raj Sarraf wrote:
> Now here is what confuses me !
best way to learn how a PC boots..
take the dumb/silly/antiquated BIOS and throw it away ...
- now figure out how it boots
- the CPU does jump to 0xFFFF FFFF as its first instruction
after power on and reset and internal self-check
what it does after that, is up to you
( what you put into the ROM at 0xFFFF FFFF aka BIOS )
- you will first need to define your interrupt vectors
- than a keyboard scanner so you can "tell it what to do"
- than a serial console so "you can see"
- than you want to read the disk sector
( the 512 byte at track-0, sector-0, head-0 (aka boot loader) )
- anything after that will be part of the filesystem
of how the heads and tracks are mapped
- gazillion fun things to do in hw or sw or fw
- the silly ami bios or phoenix bios or xxx bios restricts what
you can and cannot do
- for more fun, use a pdp11-34 or pdp11-70 or a 8080/6800
and use the switches to load your "boot program"
or the cassette tape ... or floppy disk or hard disks
or nowdays, the usb stick or the network
- How does linux boot
- From: Ritesh Raj Sarraf <email@example.com>(by way of Ritesh Raj Sarraf <firstname.lastname@example.org>)