asm version

.gitignore

@@ -1,2 +1,3 @@
 /initrd/
 /initrd.img
+/myinit/init

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

myinit/Makefile

@@ -0,0 +1,3 @@
+init: justreboot.S
+	musl-gcc -nostdlib --static justreboot.S -o init
+	strip init

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;