View source for Alpine Source Map by boot sequence

= Alpine Source Map by boot sequence =

{{Draft|Alternate message.}}

There are many different running mode/environment for Alpine. Here I try to describe what I've learned by tracing the source code.

== Boot Sequence ==

A typical boot sequence of Alpine is:

# Hardware BIOS
# Boot Loader (syslinux's isolinux)
# Initramfs (linux-grsec)
# Kernel (linux-grsec)
# Init System(openrc)
## /etc/inittab https://github.com/alpinelinux/aports/blob/master/main/alpine-baselayout/inittab
## /etc/runlevels/boot/bootmisc https://github.com/OpenRC/openrc/blob/master/init.d/bootmisc.in
## ...
# Shell(busybox's ash)

For Embedded System:

# Boot Loader(UBOOT)
# Kernel
# Init System
# Shell

For docker:
# Shell (docker image https://hub.docker.com/_/alpine/)

=== syslinux ===
The 'syslinux.cfg' of {{Pkg|syslinux}} in put in https://github.com/alpinelinux/alpine-iso/blob/master/Makefile

=== linux-grsec ===
The package kernel into ISO file method in https://github.com/alpinelinux/alpine-iso/blob/master/Makefile.

The source of kernel in {{Pkg|linux-grsec}}

=== openrc ===
The Alpine customized scripts are in https://github.com/alpinelinux/aports/tree/master/main/openrc

=== shell ===
By 'apk info -W /etc/profile', we know the default profile is customized in {{Pkg|alpine-baselayout}}  https://github.com/alpinelinux/aports/tree/master/main/alpine-baselayout

== Developer Environment ==

=== Trace code in docker ===
In any modern Linux distribution, run docker will let you get the same developer environment.
  docker run -it --name alpine alpine /bin/sh


Create the build/development inside docker
  apk update
  apk add tmux vim diffutils # my tools
  apk add alpine-sdk xorriso syslinux
  adduser YOUR_ID # There are some build scripts can't work under 'root' account.
  su - YOUR_ID
  abuild-keygen -i -a

Build one package sample(eg. openrc)
  git clone https://github.com/alpinelinux/aports
  cd aports/main/openrc  # change this line to the package which you want to change
  abuild -r
  ls -l ~/packages/x86_64/openrc*

When you shut down your PC, you can recall the docker 'alpine' container by
  docker start alpine
  docker attach alpine


=== Test ===
* Test ISO file
  qemu-system-x86_64 -enable-kvm -localtime -m 512M -vga std  \
    -drive file=YOUR_ISO_FILE ,cache=none,if=virtio

* Test Package in docker
To make sure you got the same environment of default package environment, just use docker.
  docker run --it --rm --name alpine-test alpine /bin/sh
  apk update

   # on other window copy your new apk into the 'alpine-test' container
  docker cp foo.apk alpine-test:/tmp

   # back to 'alpine-test' container
  apk fix /tmp/foo.apk

[[Category:Development]]