{{tag>[hardware apu sms initramfs]}}
=====Arch Linux - send SMS from initramfs=====
This is just a proof of concept. Might be useful to notify someone when a system has been booted and reached initramfs, and it is waiting for the decryption pass phrase.
====Install packages====
  * Install the required tools:<code>pacman -S screen expect</code>
====Configure HSDPA module====
Huawei MU609
  * The module might be configured for packet switched (PS) only. To be able to send SMS via AT commands, the module needs to be configured for CP_PS, CS or CS_ONLY, CS = circuit switched. If you also want to set up a dataconnection, configure CS_PS. If you don't include CS, you will receive the error: ''+CMS ERROR: 500'' when sending an SMS. <code># screen /dev/ttyUSB0 115200
at^syscfg=2,2,3FFFFFFF,1,2</code>

====Configure initramfs====
  * Edit the mkinitcpio configuration file: ''/etc/mkinitcpio.conf'':<code>
# Load these modules before any boot hooks are run
MODULES="ehci_hcd ohci_pci usbserial option ohci_hcd ehci_pci"

# Include these binaries
BINARIES="/usr/bin/expect /usr/bin/stty"

# Include the script and TCL dependency
FILES="/usr/lib/tcl8.6/init.tcl /usr/local/bin/init-sms.sh"

# Add custom 'sms' hook
HOOKS="base udev autodetect modconf block keyboard sms encrypt filesystems fsck"
</code>
====Create custom hook====
  * ''/usr/lib/initcpio/hooks/sms'':<code>#!/usr/bin/ash

run_hook() {
  /usr/local/bin/init-sms.sh 
}</code>
  * ''/usr/lib/initcpio/install/sms''<code>#!/bin/bash

build() {
  add_runscript
}</code>

====Create SMS script====
  * This is just a simple quick expect script. <code>
#!/usr/bin/expect

# device
set modem /dev/ttyUSB0

# keep it open
exec sh -c "sleep 3 < $modem" &

# serial port parameters (probably not needed for USB)
exec stty -F $modem 9600 raw -clocal -echo -istrip -hup

# connect
spawn -open [open $modem w+]
send "at\r"
expect "OK"

# Unlock SIM if needed.
send "at^cpin?\r"
expect { 
         # ^CPIN: SIM PIN,3,10,3,10,3
         "*CPIN: SIM PIN*" {
           send_user "SIM is locked, trying PIN...\n"
           send "at^cpin=123456\r"
           expect { 
             "OK" {
             }
             "+CME ERROR: incorrect password" {
               send_user "Wrong PIN, please configure the right PIN.\n"
             }
           }
         }

         # ^CPIN: READY,,10,3,10,3
         "*CPIN: READY*" {
           send_user "SIM is ready.\n"
         }
}

# Wait 5 seconds, device is connecting to network...
sleep 5

# set text mode
send "at+cmgf=1\r"
expect "OK"

# set GSM encoding
send "at+csmp=,,,0\r"
expect "OK"

# Configure SMS service center
send {AT+CSCA="+31653131313"}
send "\r"
expect "OK"

# Select TE character set
send {at+cscs="GSM"}
send "\r"
expect "OK"

# Send SMS to number...
send {at+cmgs="0612345678"}
send "\r"
expect "> "

# Text to send, end with \x1A = ctrl-z
send "System has reached initramfs."
send "\x1a"
</code>
====Generate new initramfs====
  * Generate new initramfs:<code>mkinitcpio -p linux</code>
  * Reboot and test!