TS-7600 initramfs

From Technologic Systems Manuals

When the unit first boots and is connected to a serial console, the output will look similar to the following:

HTLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLFLC              
>> TS-BOOTROM - built Sep  4 2013 14:49:24                                               
>> Copyright (c) 2013, Technologic Systems                                               
LLCLLLLLLLFLCLLJUncompressing Linux... done, booting the kernel.                         
Booted in 3.89s                                                                          
Initramfs Web Interface: http://ts7600-4f3029.local                                        
#       
Note: Version dates may be different depending on shiped date and the image used.


This is a minimalistic initial RAM filesystem that includes our specific utilities for the unit, and is then used to bootstrap the Linux root. The initramfs is built into the kernel image so it cannot be modified without rebuilding the kernel, but it does include 8 bits for common configuration option we call soft jumpers. These soft jumpers are set in non-volatile memory inside of the FPGA and provide persistent bits regardless of the boot media.


Soft Jumpers
Jumper Function
1 Boot automatically to Debian [1]
2 Reserved
3 Reserved
4 Enable AUFS unification on root filesystem[2]
5 Reserved
6 Reserved
7 Boot as fast as possible [3]
8 Reserved
  1. initramfs boot is default
  2. REQUIRES using the 3.14 kernel and the secondary branch mentioned in the compile instructions.
  3. This will skip all setup of networking, baseboard detection and configuration, and is not compatible with DoubleStore boot devices


There are 2 ways to manipulate soft jumpers on the board. The web interface at "http://<model>-<last 6 chars of the MAC>.local" has a list of checkboxes that will immediately change the values. The built-in 'tshwctl' command can also be used for this.

# Boot automatically to Debian:
tshwctl --setjp=1

# Or revert to the initramfs:
tshwctl --removejp=1

If a serial console is not being used, we recommend ensuring Debian's network settings are configured first before booting directly to Debian by setting JP1. Once JP1 is enabled, the initramfs does not run any network configuration utilities and Debian must set the network. See Debian's Configuring the Network section for more information.

For most development, we recommend booting to Debian. This can be accomplished by typing "exit" through the serial or telnet console from the initramfs. As discussed, setting soft jumper JP1 will cause the unit to boot automatically to Debian on future boots. Additionally, many applications are capable of running from the initramfs. The initramfs itself cannot be easily modified, and it is not recommended to do so. The initramfs however has several hooks for applications to use. Debian is mounted at "/mnt/root/" as a read only filesystem which includes the "ts/" directory which offers several hooks and config files. Note that once booted to Debian, these files are available at "/ts/" rather than "/mnt/root/ts/".


/mnt/root/ts/init

For headless applications you can create a bash script with any initialization you require in /ts/init. This does not use the same $PATH as Debian, so you should enter the full path to any applications you intend to run from this environment. The init file does not exist by default and must be created:

#!/bin/sh

/path/to/your/application &


USB update mechanism, tsinit

For implementing a custom production process or applying updates in the field, this SBC is capable of detecting a USB device and running a script. The behavior of this process can be tuned, see the config information section below. There are a few requirements of this script: the USB device itself must be the first or only USB storage device connected, the script must be on the first partition of said USB device and be named "tsinit", and the script must be world executable. PATH is passed to the tsinit script, it is what the initramfs environment PATH is, if additional PATHs are required that can be added in the tsinit script. Standard in/out are the standard console port, this means either the serial debug port, or telnet. Please note that if using telnet, output may be missed as the scripts will not wait for a telnet connection to establish, it is recommended to use a real serial port because of this.

During the USB update process, the first partition of the USB drive is mounted to "/mnt/usbdev/" of the initramfs. Then the update mechanism attempts to execute "/mnt/usbdev/tsinit" and thus launches the script. As stated above, PATH is passed to the script as well as standard in and out (linked to the console port) allowing for printed information in the script to appear on the terminal.


/mnt/root/ts/initramfs-xinit

Graphical applications should use /ts/initramfs-xinit. The xinit file is used to start up a window manager and any applications. The default initramfs-xinit starts a webbrowser viewing localhost:

#!/bin/sh
# Causes .Xauthority and other temp files to be written to /root/ rather than default /
export HOME=/root/
# Disables icewm toolbars
export ICEWM_PRIVCFG=/mnt/root/root/.icewm/

# minimalistic window manager
icewm-lite &

# this loop verifies the window manager has successfully started
while ! xprop -root | grep -q _NET_SUPPORTING_WM_CHECK
do
    sleep 0.1
done

# This launches the fullscreen browser.    If the xinit script ever closes, x11 will close.  This is why the last
# command is the target application which is started with "exec" so it will replace the xinit process id.
exec /usr/bin/fullscreen-webkit http://localhost


/mnt/root/ts/config

This config file can be used to alter many details of the initramfs boot procedure.

## This file is included by the early init system to set various bootup settings.
## if $jp7 is enabled none of these settings will be used.

## Used to control whether the FPGA is reloaded through software.
## 1 to enable reloading (default)
## 0 to disable reloading
#CFG_FPGARELOAD="0"

## By default dns-sd is started which advertises the ts<model>-<last 6 of mac> 
## telnet and http services using zeroconf.
## 1 to enable dns-sd (default)
## 0 to disable dns-sd
#CFG_DNSSD_EN="0"

## This is used to discover hosts and advertise this host over multicast DNS.
## 1 to enable mdns (default)
## 0 to disable mdns
#CFG_MDNS_EN="0"

## ifplugd is started in the initramfs to start udhcpc, and receive an ipv4ll
## address.
## 1 to enable ifplugd (default)
## 0 to disable ifplugd
#CFG_IFPLUGD_EN="0"

## By default telnet is started on port 2323.
## 1 to enable telnet (default)
## 0 to disable telnet
##CFG_TELNET_EN="0"

## The busybox webserver is used to display a diagnostic web interface that can
## be used for development tasks such as rewriting the SD or uploading new
## software
## 1 to enable (default)
## 0 to disable
##CFG_HTTPD_EN="0"

## This eanbles a reset switch on DIO 29 (TS-7700), or DIO 9 on all of the 
## boards.  Pull low to reset the board immediately.
## 1 to enable the reset sw (default)
## 0 to disable
#CFG_RESETSW_EN="0"

## The console is forwarded through xuartctl which makes the cpu console available
## over telnet or serial console.
## 1 to enable network console (default)
## 0 to disable network console
#CFG_NETCONS_EN="0"

## By default Alsa will put the SGTL5000 chip into standby after 5 seconds of 
## inactivity.  This is desirable in that it results in lower power consumption,
## but it can result in an audible popping noise.  This setting prevents 
## standby so the pop is never heard.  
## 1 to disable standby
## 0 to enable standby (default)
#CFG_SGTLNOSTBY="1"

## xuartctl is used to access the FPGA uarts.  By default it is configured to
## be IRQ driven which is optimized for best latency, but at the cost of 
## additional CPU time.  You can reduce this by specifying a polling rate.
## The xuartctl process also binds to all network interfaces which can provide a 
## simple network API to access serial ports remotely.  You can restrict this to
## the local network with the bind option.
## Configure XUART polling 100hz
## Default is IRQ driven
CFG_XUARGS="--irq=100hz"
## Configure xuartctl to bind on localhost
## Default binds on all interfaces
#CFG_XUARGS="--bind 127.0.0.1 --irq=100hz"
## For a full list of arguments, see the xuartctl documentation here:
## http://wiki.embeddedarm.com/wiki/Xuartctl#Usage

## By default the system will probe for up to 10s on USB for a mass storage device
## and mount the first partition.  If there is an executable /tsinit script in the
## root this will be executed.  This is intended for production or updates.
## 2 to enable USB init always (adds 10s or $CFG_USBTIME to startup)
## 1 to enable USB init when jp1=0 (default)
## 0 to disable USB init always
#CFG_USBINIT="2"

## The USB init script by default blocks for 10s to detect a thumb drive that 
## contains the tsinit script.  Most flash media based drives can be detected 
## in 3s or less.  Some spinning media drives can take 10s, or potentially longer.
## This options is the number of seconds to wait before giving up on the 
## mass storage device.
#CFG_USBTIME="3"

### TS-8700
## Using the TS-8700 baseboard the board will by default initialze all of the 
## ethernet ports as individual vlan ports, eg eth0.1, eth0.2, eth0,3, and eth0.4
## The alterantive option sets Port A to eth0.1, and Ports B-D to eth0.2, or
## you can configure all ethernet ports as a single eth0 port.
## See http://wiki.embeddedarm.com/wiki/TS-8700 for more information
## 2 disables any vlan and passes through all interfaces to eth0
## 1 enables "WLAN" mode setting "A" as eth0.1, and all others as eth0.2
## 0 enables "VLAN" mode for 4 individual ports (default)
#CFG_4ETH="1"

### TS-4712 / TS-4720
## These boards include an onboard switch with 2 external ports.  By default
## the switch will detect if it is on a known baseboard that supports the second
## ethernet switch port, and set up VLAN rules to define eth0.1 and eth0.2.  The
## other option is to configure the switch to pass through the packets to eth0
## regarless of port.
## 2 Disable VLAN and pass through to eth0
## 1 Enable VLAN on all baseboards
## 0 Enable VLAN on supported baseboards (Default)
#CFG_2ETH="1"