bootrepair floppy or CD 105

Hello, mayayana,

At this point I have seen Peter's response, which I find humurous. Implicated, but not involved. It is like a riddle you have to solve.

I know Peter wants that people learn to read manpages and how to investigate everything themselves. So go and read man lilo, and see if you can find where it says that lilo.conf is not involved during boot. I haven't read that manpage for many years, and it has likely changed a bit since, but I guess you won't find anything on first reading. Perhaps on third.

The information you put in lilo.conf is used by lilo when you run lilo. Clear? Don't you see the difference? Blind? lilo, lilo, one runs under Linux and installs a boot loader in the mbr (or where lilo.conf says), the other runs without any kernel, but boots a kernel. Everybody sees that, don't you? Guess which of the two reads the config file. Lilo? Wrong! Lilo!

Lilo patches some numbers into the mbr, telling mbr where to find the rest of lilo. That is, the other lilo. It also stores somewhere the sector numbers (addresses) of the sectors that contain the kernel. In this way, when you boot, lilo does not need to understand file system data structures. It just loads the sectors listed.

You changed the parbreastion table, but I guess lilo didn't care much about the parbreastion table. It just loads the sectors listed. The sector numbers are relative to the start of the disk anyway, Lilo loads the same sectors as before and thereby loads the same kernel as before. It also provides the same command line options to the kernel as before. Ooops!

But which device is this, really?

init is not initrd. init is the first program linux runs, appart from the kernel itself. It used to be the **only** program the kernel would run by itself, all other programs used to be started by init, or by programs started by init. Nowadays this is no longer quite true, but it is still a usefull "lie". See if you have a program calledsbin-init. Linux looks for init a couple of places,etc-init,bin-init,sbin-init,init, ... I don't know the exact list by heart, so I am making it up a little, but the real list does not look all that different - execpt I believe the real list ends withbin-sh, so in an emergency, the kernel tries to run a shell, if it cannot find any init. But I guess the kernel did not findbin-sh either.

How come?

Notice that if you have an initrd in your setup (it is not required if your kernel has all it needs to moun the real root file system), the kernel starts the init program it finds on the initrd, and this init program eventually issues the commands to the kernel to mount the real root, and then "pivots" the two file systems so the real one becomes the top file system. After that the provisional init stops. Exits. The kernel is not really aware that the ramdisk is something provisonal. From the kernel's perspective the system is up and running, and init is doing its things, and... oops, "init" exited! Restart it! But this time, the stringsbin-init,sbin-init, etc., point the kernel to directories on the real root file system. If and when the kernel eventually finds init a second time, it is not the same provisional init. It's the real one.

No

No

Yes --boot-vmlinuz-2.6.blah.blah

Lilo has finished its task and is happy. The kernel is running. Lilo doesn't run any more.

Would it? Grub does something similar to what you suggest, but lilo does not understand files.

No - yes - no - argh, what do you say in English, no or yes? No, the message above was NOT from lilo. No, the message above was NOT from the process of booting the kernel. (I.e. not from loading the kernel into memory, and not even from the kernel's initialization of its data structures.) Yes, it is from booting, the kernel boots the userspace programs by starting init. Init would take the booting further by running the boot scripts as instructed to inetc-inittab.

Getting hotter. There was a game in my infancy which I believe exists identically in many countries. You have to search for something hidden, and everybody else knows where it is. As you approach it, you are told it's getting hotter.

The initrd is a file system image that the boot loader loads into memory. The boot loader pbuttes an extra command line option to the kernel, and the kernel uses the initrd as a ram disk. Initrd = Initial ram disk.

The kernel mounts it as a provisional root file system, runs a provisional init program (which used to be called "linuxrc", but nowadays... I don't remember.) The purpose is to load kernel modules needed to access the real root file system. This is so the kernel proper can be made slim. When the real root file system has been mounted, the initrd is discarded.

To learn the details here, you need to mount the initrd again, using the -o loop option (and a few more tricks), and look at the program there. It is a script written for a rather special "shell" called "nash". Man nash. On RedHat-Fedora, anyway. YMMV.

-Enrique