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MrMe01
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PostPosted: Sun Nov 29, 2015 12:24 pm    Post subject: genkernel - removing initramfs Reply with quote

Just a quick question,

How do I remove initramfs without the system panicking? I've extracted the initramfs onto the system but it panics. Does genkernel inform the kernel that it'll be built with an initramfs? If so, how can I change that without recompiling the kernel?
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NeddySeagoon
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PostPosted: Sun Nov 29, 2015 12:37 pm    Post subject: Reply with quote

MrMe01,

Genkernel builds a fully modular kernel and puts the modules into the initrd.
The initrd is a temporary root filesystem in a file.

The bootloader loads the kernel and initrd into RAM and jumps to the kernel start address.
The kernel decompresses itself, does some initlaisation, then mounts the initrd as its root filesystem.
It loads the modules.

Some of these modules are needed to mount the real root filesystem, since they are for your SATA chip set, file systems and so on.

Unaided, a genkernel kernel knows how to mount the initrd as root but it cannot communicate with the HDD. That's one of the things the initrd provides.

You need a kernel that can mount the HDD root without outside help.
Pappy wrote it up at kernel-seeds. The method is still valid but the seeds are out of date.
You can still use genkernel if you must but you need to switch some settings from <M> to <*>.
Then you don't need an initrd at all.
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MrMe01
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PostPosted: Sun Nov 29, 2015 12:43 pm    Post subject: Reply with quote

Thanks NeddySeagoon,

I asked as a quick and dirty workaround for the problem I'm facing here,
https://forums.gentoo.org/viewtopic-t-1034188-highlight-.html

I'm not sure if this is on the system or inside the initramfs.
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szatox
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PostPosted: Sun Nov 29, 2015 12:49 pm    Post subject: Reply with quote

Quote:
I've extracted the initramfs onto the system but it panics

What is the message for kernel panic?
Also, whow us your bootloader config and /etc/fstab.
Modules needed for SATA controller is one thing, but it's also possible your boot options are incorrect with the new setup
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MrMe01
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PostPosted: Sun Nov 29, 2015 1:04 pm    Post subject: Reply with quote

szatox wrote:
Quote:
I've extracted the initramfs onto the system but it panics

What is the message for kernel panic?
Also, whow us your bootloader config and /etc/fstab.
Modules needed for SATA controller is one thing, but it's also possible your boot options are incorrect with the new setup


Running GRUB 0.97, with the line for initramfs #'ed out, fstab is setup for a single partition. I just rebooted with fstab in place, no difference.

I should explain that I'm trying to make a modular set of images, as explained here https://forums.gentoo.org/viewtopic-t-1034188-highlight-.html, at the moment I'm just hacking stuff to get me from GRUB to the CLI login prompt.
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Buffoon
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PostPosted: Sun Nov 29, 2015 1:11 pm    Post subject: Reply with quote

Kernel has to mount root filesystem in order fstab being read. Genkernel has HDD controller support as module in initramfs. Remove it and it will never gain access to the hard drive.
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MrMe01
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PostPosted: Sun Nov 29, 2015 1:24 pm    Post subject: Reply with quote

Buffoon wrote:
Kernel has to mount root filesystem in order fstab being read. Genkernel has HDD controller support as module in initramfs. Remove it and it will never gain access to the hard drive.


I've worked that out :P

I'm just trying to hack a system together from GRUB to CLI login at the moment, as I've previously commented on. I just want to know how the system boots and what files are used to get there, but I've come unstuck. I'd appreciate any input you'd have on this though, https://forums.gentoo.org/viewtopic-t-1034188-highlight-.html.

I'm trying to work out if what's going on is inside the initramfs or on the filesystem itself as I do see (booting) initramfs
http://s23.postimg.org/rai15h6kb/seg.png
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NeddySeagoon
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PostPosted: Sun Nov 29, 2015 2:26 pm    Post subject: Reply with quote

MrMe01,

From your image, the initrd has done its stuff, or was not needed as OpenRC is running.

What do you have in /etc/group and /etc/passwd?
There are no passwords in /etc/passwd any more.
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szatox
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PostPosted: Sun Nov 29, 2015 4:47 pm    Post subject: Reply with quote

Quote:
Kernel has to mount root filesystem in order fstab being read.

Kernel can't read fstab posted at the forums either. However this:
Quote:
show me you grub.conf and fstab

is much more clear than this:
Quote:
describe your general setup in a way you think would give us some insight into your position allowing us spot potential pitfalls, so we can waste time reading something completely useless because if you knew what is suitable you would have already posted it in the first place to get you precious hints sooner

And finding the pitfalls is much easier when we know what you're doing and how you fail.
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MrMe01
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PostPosted: Sun Nov 29, 2015 5:12 pm    Post subject: Reply with quote

szatox wrote:
Quote:
Kernel has to mount root filesystem in order fstab being read.

Kernel can't read fstab posted at the forums either. However this:
Quote:
show me you grub.conf and fstab

is much more clear than this:
Quote:
describe your general setup in a way you think would give us some insight into your position allowing us spot potential pitfalls, so we can waste time reading something completely useless because if you knew what is suitable you would have already posted it in the first place to get you precious hints sooner

And finding the pitfalls is much easier when we know what you're doing and how you fail.


Your point being?

If you had read the first post on the other thread, you'd know I'm not looking for a run of the mill answer.

From that same thread, in the first post, you'd also see that GRUB was working. It's also quite plausible that fstab was not to blame here as it's not needed this early in the boot process. In fact, I'd hazard a guess that init would complain about it not being there, after the panic not having an initramfs would cause.
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szatox
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PostPosted: Mon Nov 30, 2015 6:26 pm    Post subject: Reply with quote

My point being you don't bother to read, refuse to provide clues, and expect a helpful answer pulled out of the thin air.
We've asked you about 5 or 6 different things, you failed to provide any of them. Fine, stay where you are.
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MrMe01
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PostPosted: Tue Dec 01, 2015 3:35 am    Post subject: Reply with quote

szatox wrote:
My point being you don't bother to read, refuse to provide clues, and expect a helpful answer pulled out of the thin air.
We've asked you about 5 or 6 different things, you failed to provide any of them. Fine, stay where you are.


To reiterate what I am doing, because I obviously have not made it clear;

I have a clone of a system that I have deliberately broken by moving all but the files in /kernel (see below) into a folder called 1, I am moving files from that folder where the original system structure remains . I am making a list of the files that is required to boot the system, by making it break and giving it what it needs. So far it has not asked for an fstab. Therefore, I haven't copied it into /etc. I am using ldd to determine the .so* files required. This has stopped working. I am using my DSLR to capture the screen before what I assume is agetty takes over and removes anything of value from the screen.


It's GRUB 0.97, this isn't complicated to work out what it looks like.

I haven't copied in the files Neddy had mentioned as I'm stumped for an answer as to what the system is looking for next. I have copied in /etc/passwd and group, but the error remains.

But, for the sake of what you're asking for,
Code:

grub.conf
title Gentoo Linux (sda2 kernel)
root (hd0,1)
kernel /kernel/kernel-genkernel-x86-4.1.12-gentoo root=/dev/sda2
initrd /kernel/initramfs-genkernel-x86-4.1.12-gentoo


/kernel to make sure it's booting the right partition

Code:

fstab
# NOTE: If your BOOT partition is ReiserFS, add the notail option to opts.
#/dev/BOOT      /boot      ext2      noauto,noatime   1 2
/dev/sda2         /      ext3      noatime      0 1
/dev/SWAP      none      swap      sw      0 0
/dev/cdrom      /mnt/cdrom   auto      noauto,ro   0 0
/dev/fd0      /mnt/floppy   auto      noauto      0 0


Code:

Group
root:x:0:root
bin:x:1:root,bin,daemon
daemon:x:2:root,bin,daemon
sys:x:3:root,bin,adm
adm:x:4:root,adm,daemon
tty:x:5:
disk:x:6:root,adm
lp:x:7:lp
mem:x:8:
kmem:x:9:
wheel:x:10:root
floppy:x:11:root
news:x:13:news
uucp:x:14:uucp
console:x:17:
audio:x:18:
cdrom:x:19:
tape:x:26:root
video:x:27:root
cdrw:x:80:
usb:x:85:
users:x:100:
portage:x:250:portage
utmp:x:406:
nogroup:x:65533:
nobody:x:65534:
sshd:x:22:
man:x:15:
input:x:249:


Code:

passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/bin/false
daemon:x:2:2:daemon:/sbin:/bin/false
adm:x:3:4:adm:/var/adm:/bin/false
lp:x:4:7:lp:/var/spool/lpd:/bin/false
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
news:x:9:13:news:/var/spool/news:/bin/false
uucp:x:10:14:uucp:/var/spool/uucp:/bin/false
operator:x:11:0:operator:/root:/bin/bash
portage:x:250:250:portage:/var/tmp/portage:/bin/false
nobody:x:65534:65534:nobody:/var/empty:/bin/false
sshd:x:22:22:added by portage for openssh:/var/empty:/sbin/nologin
man:x:13:15:added by portage for man-db:/usr/share/man:/sbin/nologin


I hope this helps.
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MrMe01
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PostPosted: Tue Dec 01, 2015 3:59 am    Post subject: Reply with quote

Here's a list of the files I have so far.
Code:
/kernel
      initramfs-genkernel-x86-4.1.12-gentoo
      kernel-genkernel-x86-4.1.12-gentoo
/sbin
      agetty
      halt
      init
      openrc
      rc
      reboot
      shutdown
      switch_root
/lib
      ld-2.21.so
      ld-linux.so.2
      libblkid.so.1
      libblkid.so.1.1.0
      libc-2.21.so
      libc.so.6
      libdl-2.21.so
      libdl.so.2
      libeinfo.so
      libeinfo.so.1
      libmount.so.1
      libmount.so.1.1.0
      libncurses.so.5
      libncurses.so.5.9
      libpam.so.0
      libpam.so.0.84.1
      libpcre.so.1
      libpcre.so.1.2.4
      libpthread-2.21.so
      libpthread.so.0
      librc.so
      librc.so.1
      libreadline.so.6
      libreadline.so.6.3
      libutil-2-21.so
      libutil.so.1
      libuuid.so.1
      libuuid.so.1.3.0
      /rc
         /bin
            eerror
            eval_ecolors
            ebegin
            fstabinfo
            einfo
            mountinfo
            checkpath
         /sh
            init.sh
            functions.sh
            gendepends.sh
            rc-functions.sh
/etc
      inittab
/bin
      sh
      bash
      mount
      cat
      grep
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NeddySeagoon
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PostPosted: Tue Dec 01, 2015 8:38 pm    Post subject: Reply with quote

MrMe01,

Edit your inittab ...
Code:
# TERMINALS
c1:12345:respawn:/sbin/agetty 38400 --noclear tty1 linux
that will stop the terminal being cleared at the end of the boot process.

What do you have in /dev and how is /dev being porulated?
The kernel option DEVTMPFS is one answer but if /dev is empty, not much happens.
You need at least /dev/null and /dev/console device nodes. You don't seen to have a /dev at all.

With /etc/init.d and /etc/conf.d both empty, Openrc won't find any of the scripts and configs that it needs.
Code:
roy@NeddySeagoon_Static ~ $ /sbin/rc-update | grep sys
                devfs |                       sysinit
                dmesg |                       sysinit                       
                sysfs |                       sysinit
         tmpfiles.dev |                       sysinit

You need to get those services running. More conventional users than me will have udev or a udev replacement.
I have a static /dev.

You will also find
Code:
$ /sbin/rc-update | grep boot
               binfmt | boot                         
             bootmisc | boot                         
                 fsck | boot                         
             hostname | boot                         
              hwclock | boot                         
              keymaps | boot                         
           localmount | boot                         
             loopback | boot                         
              modules | boot                         
                 mtab | boot                         
               net.lo | boot                         
               procfs | boot                         
                 root | boot                         
                 swap | boot                         
            swapfiles | boot                         
               sysctl | boot                         
         termencoding | boot                         
       tmpfiles.setup | boot                         
              urandom | boot         
useful. Well, swapfiles is only useful if you have swap in a file.
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