Using BusyBox to make Iniramfs

One of the ways to start Linux kernel is Initramfs + kernel. Where INIRAMFS can be made using BusyBox. This example uses BusyBox v1.22.1 to make Iniramfs in Ubuntu 16.04 64bit.

# # Download BusyBox
[BusyBox]: https://busybox.net/

# # Configure, compile
1. Configure
"Shell
$ make Menuconfig
```
> If ' Make Menuconfig ' encounters errors, consider installing Libcurses5-dev

Busybox Settings-> Build Options-> build Busybox as a static binary (no shared libs)
Busybox Settings-> Build Options-> Cross Compiler Prefix # arm-linux-gnueabi-

2. Compile
"Shell
$ make-j5 Arch=arm Install
```
Notice the Echo
> would probably need to make your busybox binary
Setuid root to ensure all configured applets would
Work properly.

The results of the compilation are stored in _install/.
"Shell
# in _install/bin
$ chmod +s BusyBox
# in _install
$ find. | Cpio-o--FORMAT=NEWC >. /rootfs.img
$ cd ...
$ gzip-c rootfs.img > rootfs.img.gz
```
Thus, ' rootfs.img.gz ' is Iniramfs.

# # Use
If you have previously compiled a completed Linux kernel (zimage), you can use it in a manner similar to the following
"Shell
$./qemu-system-arm-m versatilepb-m 128m-kernel zimage-initrd rootfs.img.gz-append "Root=/dev/ram rdinit=/bin/sh cons Ole=ttyama0 "-nographic
```
The current situation is to stay in the Ramfs file system, the observed warning is "/bin/sh:can ' t access tty;" Job control turned off.

# # Refenrece
[BusyBox for Arm on QEMU]: https://balau82.wordpress.com/2010/03/27/busybox-for-arm-on-qemu/