This is a text-only version of the following page on https://raymii.org:
---
Title : Bare Metal Vi, boot into Vi without an OS!
Author : Remy van Elst
Date : 22-04-2023 22:30
URL : https://raymii.org/s/blog/Bare_Metal_Boot_to_Vi.html
Format : Markdown/HTML
---
This guide shows you how to run `Vi` without an operating system, bare metal. This is a follow up on my article from 2014 where I made a custom linux distro that would [Boot to Vim, VIM as PID 1](https://raymii.org/s/blog/Vim_as_PID_1_Boot_to_Vim.html). This time we go further, we boot into `Vi` without an operating system. This is made possible by [Cosmopolitan](https://justine.lol/cosmopolitan/index.html), a `libc` that outputs a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable.
Here is a screenshot of bare metal `Vi`:
![bare metal vi][5]
<p class="ad"> <b>Recently I removed all Google Ads from this site due to their invasive tracking, as well as Google Analytics. Please, if you found this content useful, consider a small donation using any of the options below:</b><br><br> <a href="https://leafnode.nl">I'm developing an open source monitoring app called Leaf Node Monitoring, for windows, linux & android. Go check it out!</a><br><br> <a href="https://github.com/sponsors/RaymiiOrg/">Consider sponsoring me on Github. It means the world to me if you show your appreciation and you'll help pay the server costs.</a><br><br> <a href="https://www.digitalocean.com/?refcode=7435ae6b8212">You can also sponsor me by getting a Digital Ocean VPS. With this referral link you'll get $100 credit for 60 days. </a><br><br> </p>
The article [Vim as PID 1, Boot to Vim][1] recently hit the front page of
HackerNews and [one of the commenters stated][3] the following:
> I bet it wouldn't be too extremely hard to port Vim to [cosmopolitan][2]
and run it without an OS (BIOS mode in cosmopolitan). (by `etaioinshrdlu` )
Turns out, that's mostly possible. Not actual Vim, but a minimal Vi
clone compiles just fine and runs without any OS.
Super cool, fast startup time, the only thing it lacks is filesystem
support, so you cannot save or load your files. But hey, who needs that?
I'm compiling a small Vi clone, [viless][4], which is the BusyBox Vi clone but
patched to run without BusyBox, and a few patches by me to make it compile
inside cosmopolitan.
### Compiling Vi with Cosmopolitan
These instructions are based on the [instructions on the cosmopolitan source][2].
I'm running them on a Debian 11 system, but Ubuntu should work too.
Make sure you can compile C code and have `git`:
apt install build-essential git unzip
Clone the `Vi` code:
git clone https://github.com/RaymiiOrg/viless
Test if you can compile it:
cd viless
make
You should have an executable `vi` binary in the current folder. Try to run it:
./vi
Exit with `:q!`. If that all worked you can continue with the cosmopolitan part.
Download the required files:
wget https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-2.2.zip
Unzip cosmopolitan:
unzip cosmopolitan-amalgamation-2.2.zip
Compile `Vi` with the cosmopolitan runtime:
gcc -g -Os -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \
-fno-omit-frame-pointer -pg -mnop-mcount -mno-tls-direct-seg-refs \
-gdwarf-4 \
-o vi.com.dbg \
vi.c \
-fuse-ld=bfd -Wl,-T,ape.lds -Wl,--gc-sections \
-include cosmopolitan.h crt.o ape-no-modify-self.o cosmopolitan.a
Use `objcopy` to make the actual binary you can run:
objcopy -S -O binary vi.com.dbg vi.com
The file `vi.com` should be executable on your linux system, but also on all the platforms stated above.
### Run Vi in QEMU
On the same Ubuntu machine, make sure you've installed `qemu`:
sudo apt install qemu-system-x86
Then execute the following command to boot your freshly created `vi.com` disk(?):
qemu-system-x86_64 -m 16 -nographic -drive file=vi.com,format=raw,index=0,media=disk
This will launch you into `Vi`. Exit with `CTRL+A, X` (to exit QEMU). If you
want to have a separate window as I did in the screenshots, remove the `-nographic`
option and in the window that pops up, select the `View` menu, then choose
`serial0`.
![bare metal vi][5]
I currently only have [a Raspberry Pi 4][6] as my main desktop so I cannot
try booting from a floppy or USB drive on real hardware. If you can, please
let me know if it works. You will probably not see anything on the screen
but on the serial port.
Update: I've loaned an x86 laptop and the `vi.com` file runs when written to disk
using `dd`:
# replace /dev/sdX with your USB device
dd if=vi.com of=/dev/sdX conv=notrunc
The [vi.com][7] file I compiled is available [for download][7].
You could try to compile the actual `Vim` and see if that works. If you do,
please let me know about it!
### Patches for viless
These are the changes I made to [viless][4] to make it compile with
Cosmopolitan:
From 96aa85f886249ad7fd097a413c28ca4771c0326e Mon Sep 17 00:00:00 2001
From: Remy van Elst <RaymiiOrg@users.noreply.github.com>
Date: Sat, 22 Apr 2023 20:27:05 +0200
Subject: [PATCH] Patches for cosmopolitan
---
vi.c | 60 ++----------------------------------------------------------
1 file changed, 2 insertions(+), 58 deletions(-)
diff --git a/vi.c b/vi.c
index 1d7f9ac..4e959fc 100644
--- a/vi.c
+++ b/vi.c
@@ -22,27 +22,14 @@
* A true "undo" facility
* An "ex" line oriented mode- maybe using "cmdedit"
*/
+
+#define STANDALONE
#ifdef STANDALONE
#define BB_VER "version 2.62"
#define BB_BT "brent@mbari.org"
#define _GNU_SOURCE
-#include <stdarg.h>
-#include <string.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <setjmp.h>
-#include <sys/ioctl.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <errno.h>
-#include <ctype.h>
-#include <termios.h>
-#include <poll.h>
#define vi_main main
#define CONFIG_FEATURE_VI_MAX_LEN 4096
@@ -104,8 +91,6 @@ typedef signed char smallint;
#endif
-#include <limits.h>
-
/* the CRASHME code is unmaintained, and doesn't currently build */
#define ENABLE_FEATURE_VI_CRASHME 0
@@ -509,22 +494,6 @@ void *xzalloc(size_t size)
return memset(xmalloc(size), 0, size);
}
-void *xstrdup(const char *s)
-{
- void *ptr = strdup(s);
- if (ptr) return ptr;
- perror("strdup");
- exit(66);
-}
-
-void *xstrndup(const char *s, size_t n)
-{
- void *ptr = strndup(s, n);
- if (ptr) return ptr;
- perror("strndup");
- exit(67);
-}
-
void *xrealloc(void *old, size_t size)
{
void *ptr = realloc(old, size);
@@ -2475,31 +2444,6 @@ static int rawmode(void)
tcsetattr(0, TCSANOW, &term_vi);
unsigned tics = 1;
- switch (cfgetispeed(&term_vi)) {
- case B600:
- tics = 2;
- break;
- case B300:
- tics = 4;
- break;
- case B200:
- tics = 6;
- break;
- case B150:
- tics = 7;
- break;
- case B134:
- tics = 8;
- break;
- case B110:
- tics = 10;
- break;
- case B75:
- tics = 15;
- break;
- case B50:
- tics = 21;
- } //determines how long to wait for ESCAPE sequences
ticsPerChar = tics;
return 0;
}
[1]: /s/blog/Vim_as_PID_1_Boot_to_Vim.html
[2]: https://github.com/jart/cosmopolitan
[3]: https://news.ycombinator.com/item?id=35664284
[4]: https://github.com/RaymiiOrg/viless
[5]: /s/inc/img/bare_metal_vi.png
[6]: /s/blog/Using_IceWM_and_sharing_my_config_and_tips_tricks.html
[7]: /s/inc/downloads/vi.com
---
License:
All the text on this website is free as in freedom unless stated otherwise.
This means you can use it in any way you want, you can copy it, change it
the way you like and republish it, as long as you release the (modified)
content under the same license to give others the same freedoms you've got
and place my name and a link to this site with the article as source.
This site uses Google Analytics for statistics and Google Adwords for
advertisements. You are tracked and Google knows everything about you.
Use an adblocker like ublock-origin if you don't want it.
All the code on this website is licensed under the GNU GPL v3 license
unless already licensed under a license which does not allows this form
of licensing or if another license is stated on that page / in that software:
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
Just to be clear, the information on this website is for meant for educational
purposes and you use it at your own risk. I do not take responsibility if you
screw something up. Use common sense, do not 'rm -rf /' as root for example.
If you have any questions then do not hesitate to contact me.
See https://raymii.org/s/static/About.html for details.