Boot to Vim, Vim as Pid 1
Published: 18-09-2014 | Author: Remy van Elst | Text only version of this article
As we all know, nobody uses emacs.
The above statement is ment to start a flamewar. Please do so, see the contact page to contact me.
No, all joking aside, I found it to be a good article and wanted to see how I could do that with Vim. Not in User Mode Linux, but by creating an actual ISO. Boot to Vim, as you might want to call it.
This is actually fairly simple. Compile vim statically, set it as
boot and you're done.
We are going to use small (9MB) distro named Tiny Core, Core edition and customize that to boot right into our static build of Vim.
Please read and follow my tutorial on building a statically linked Vim. This will give you an executable we will use later on in the tutorial.
You will need a few tools to build the ISO, namely
mkisofs. These can probably be installed with your package
manager. Please do that first.
First create a folder for building:
mkdir vim-as-pid-1 cd vim-as-pid-1
Also create a few folders for the ISO build:
mkdir /tmp/isomount mkdir extract
Download the latest Tiny Core, Core edition (without GUI):
Copy the files from the ISO:
mount Core-current.iso /tmp/isomount/ -o loop,ro cp -a /tmp/isomount/boot /tmp/
This creates a
/tmp/boot folder with the
core.gz and boot loader. Don't
forget to umount it:
We will use the
/tmp/boot folder later on when putting back together the ISO.
Changing the ISO
Go into the folder where we will extract the
core.gz root filesystem:
cpio to extract the
zcat /tmp/boot/core.gz | cpio -i -H newc -d
We now have an extracted root filesystem:
# ls bin dev etc home init lib linuxrc mnt opt proc root run sbin sys tmp usr var
Place the earlier built static Vim in the
cp ~/vim bin/
You can do more customizations, for example, editing the boot loader message.
That is in a file named
# vim /tmp/boot/isolinux/boot.msg ^L _ ( - Boot to Vim //\ Vim as Pid 1, because Awesome! v_/_ https://raymii.org/ Press <Enter> to begin or F2, F3, or F4 to view boot options.
Changing the inittab
To boot in to Vim right away we need to change the init configuration. Edit the following file:
Change the following lines:
::sysinit:/etc/init.d/rcS tty1::respawn:/sbin/getty 38400 tty1
Do note that this does not actually make Vim PID 1. Init will still manage Vim,
and do stuff like
fsck and mount the root partition read/write. If you want to
go barebones, add
init=/bin/vim to the bootloader (
isolinux.cfg). Then, from
:!fsck /dev/sda and
mount -o remount,rw /.
Building a new ISO
Make sure you are still in the
extract folder. Issue the following command to
build a new
tinycore.gz file which the ISO will use as it's
find | cpio -o -H newc | gzip -2 > ../tinycore.gz
Copy that over the original
core.gz file in
/tmp/boot which we copied
cp ../tinycore.gz /tmp/boot/core.gz
Create a new folder for the new ISO build files:
/tmp/boot folder to it:
cp -a /tmp/boot /tmp/newiso/
Build a new ISO using
cd /tmp/ mkisofs -l -J -R -V Boot_To_Vim -no-emul-boot -boot-load-size 4 -boot-info-table -b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat -o Boot_to_Vim.iso newiso
You now have a file in
ls -la /tmp/Boot_to_Vim.iso -rw-r--r-- 1 root root 11044864 Sep 17 08:05 /tmp/Boot_to_Vim.iso
You can use this to boot a VM, or burn an ISO. If you exit
vim, it will
You can start up a real shell by giving the
:!sh command, in command mode. To
shut down, issue the
More info on remastering Tiny Core can be found here.
Tags: blog , compile , emacs , mips , tiny-core , vim