From 1fae0a8d8228995cd54bd70a36473f7e662ebaac Mon Sep 17 00:00:00 2001
From: Pavel 'LEdoian' Turinsky <ledoian@matfyz.cz>
Date: Thu, 27 Feb 2025 02:08:21 +0100
Subject: [PATCH] asm version

---
 .gitignore          |  1 +
 create.sh           |  9 +++++----
 myinit/Makefile     |  3 +++
 myinit/justreboot.S | 10 ++++++++++
 4 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 myinit/Makefile
 create mode 100644 myinit/justreboot.S

diff --git a/.gitignore b/.gitignore
index d3b8d86..e3de845 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /initrd/
 /initrd.img
+/myinit/init
diff --git a/create.sh b/create.sh
index 8e656db..c2e32a1 100755
--- a/create.sh
+++ b/create.sh
@@ -4,11 +4,12 @@
 
 set -eu
 
-mkdir "initrd"
-cp "./init" "initrd/"
+pushd myinit
+make
+popd
 
-busybox="$(which busybox)"
-cp "$busybox" "initrd/busybox"
+mkdir "initrd"
+cp "./myinit/init" "initrd/"
 
 pushd "./initrd"
 find . | cpio -o -H newc > ../initrd.img
diff --git a/myinit/Makefile b/myinit/Makefile
new file mode 100644
index 0000000..bb98cc9
--- /dev/null
+++ b/myinit/Makefile
@@ -0,0 +1,3 @@
+init: justreboot.S
+	musl-gcc -nostdlib --static justreboot.S -o init
+	strip init
diff --git a/myinit/justreboot.S b/myinit/justreboot.S
new file mode 100644
index 0000000..a859dff
--- /dev/null
+++ b/myinit/justreboot.S
@@ -0,0 +1,10 @@
+#include <sys/syscall.h>
+
+.globl _start
+
+_start:
+	movq $__NR_reboot, %rax;
+	movq $0xfee1dead, %rdi;
+	movq $0x05121996, %rsi;
+	movq $0x4321fedc, %rdx;
+	syscall;