Where is there good information about low level PC booting?

I'm interested in writing a boot loader for USB sticks that l开发者_如何转开发ooks for a directory of ISOs and gives you the option to boot one of them as if it were a bootable CD. This is basically so I have a menu driven program that allows me to install one of several different distributions off of a USB stick.

Where would I go to figure out how to make this work? Do I need to install some kind of BIOS hack to allow remapping of CD blocks to blocks in the filesystem? How would that work once the boot from the CD had enough marbles to start trying to access the device directly?

are you looking to learn how bootloading works? if so, you could check out the grub docs here: http://www.gnu.org/software/grub/

otherwise, if you're trying to create a usb bootloader that can load a variety of operating systems, this tutorial looks like it covers it quite nicely: http://www.freesoftwaremagazine.com/articles/grub_intro/

I don't think it will dynamically build a loader of operating systems as they are available by reading the contents of a directory.