Ts75XX initrd

From Technologic Systems Manuals

After the board is first booted you will be at this shell:

  >> TS-BOOTROM - built Oct 12 2011 13:35:38
  >> Copyright (c) 2009, Technologic Systems
  >> Booting from SD card...
  .
  .
  .
  >> Booted from: SD card                 Booted in: 3.93 seconds
  >> SBC Model number: TS-XXXX            SBC Sub-model number: 0
  >> CPU clock rate: 250MHz               RAM size: 64MB
  >> NAND Flash size: 256MB               NAND Flash Type: 0xdcec (Samsung)
  >> MAC number: 00:D0:69:4F:6F:04        SBC FPGA Version: 7
  >> Temperature Sensor: 37.500 degC      MODE1 bootstrap: ON
  >> RTC present: YES                     Date and Time: Jan  1 1970 00:00:03
  >> MODE2 bootstrap: OFF                 SD card size: 1886MB
  >> Offboard SPI flash type: Micron      Offboard SPI flash size: 8MB
  >> XUARTs detected: 3                   CAN present: NO
  >> Linux kernel version: 2.6.24.4       Linux kernel date: Jun 8 2011
  >> Bootrom date: Oct 12 2011            INITRD date: Dec 27 2011
  >> ts7500ctl date: Jun  8 2011          sdctl date: Jun  8 2011
  >> canctl date: Jun  8 2011             nandctl date: Aug 15 2011
  >> spiflashctl date: Aug 15 2011        xuartctl date: Aug 15 2011
  >> dioctl date: Feb 10 2011             spictl date: Jan 24 2011
  >> dmxctl date: Jun  8 2011             busybox date: Jun 30 2010 (v1.14.2)
  >> ts7500.subr date: Jun 10 2011        daqctl date: Aug 15 2011
  >> linuxrc date: Aug 31 2011            rootfs date: Jan  1 1970
  >> MBR date: Jul 14 2009
  
  Type 'tshelp' for help
  # 
Note: Your version dates may be different depending on ship date and the image used. On newer units, "Offboard SPI" and "Onboard SPI" flashes may show "unknown" for the type. This is purely cosmetic and is no cause for concern. The SPI flash can be queried with the 'spiflashctl' tool which will return a proper manufacturer and device ID.

This is a busybox shell which presents you with a very minimalistic system. While this has access to many Debian applications, it is important to note that this is not Debian. This environment will allow very fast boot times closer to 2-4 seconds, while Debian takes closer to 30-45 seconds but provides an init system and a more standard environment. As described in the previous section, the kernel and initrd are copied into RAM so any changes to this filesystem are temporary. You can commit changes using the "save" command.

For most development you will want to boot to the Debian filesystem which can be reached by typing "exit" through the serial console, or by relinking the linuxrc script to make the board automatically boot to Debian:

rm linuxrc; ln -s /linuxrc-sdroot /linuxrc; save

The linuxrc-sdroot script will actually mount and boot to the Debian filesystem on the SD or XNAND depending which device you used to boot. You can boot to a different Debian partition by using one of the other linuxrc scripts:

Script Function
linuxrc-fastboot (default) Boots immediately to a shell in ramdisk. This will mount whichever boot medium you have selected to /mnt/root/. When you type 'exit', it will boot to that medium.
linuxrc-nandmount Same as the linuxrc-fastboot script, but will mount and boot the debian partition from NAND.
linuxrc-sdmount Same as the linuxrc-fastboot script, but will mount and boot the debian partition from SD.
linuxrc-sdroot Boots immediately to the Debian stored on either SD or NAND depending on which media the SBC was booted from.
linuxrc-sdroot-readonly Same as linuxrc-sdroot, except it will mount the Debian partition read only while creating a unionfs with a ramdisk. Changes will only happen in memory and not on disk.
linuxrc-usbroot Mounts the first partition of the first detected USB mass storage device and boots there.

Once you have booted to Debian you can force the boot process to stop in the fastboot shell/initd on next bootup with:

touch /fastboot

The small default initrd is only 2Mbyte but there is space for approximately 800 Kbyte of additional user applications. This constraint is important if you are running your application without Debian, but only from the initrd. If you have the Debian partition available you can access that partition under /mnt/root/ to run your application.

The compiled instance of busybox includes several internal commands listed below:

   # /bin/busybox --help
   BusyBox v1.14.2 (2009-08-07 14:43:48 MST) multi-call binary
   Copyright (C) 1998-2008 Erik Andersen, Rob Landley, Denys Vlasenko
   and others. Licensed under GPLv2.
   See source distribution for full notice.
   
   Usage: busybox [function] [arguments]...
      or: function [arguments]...
   
           BusyBox is a multi-call binary that combines many common Unix
           utilities into a single executable.  Most people will create a
           link to busybox for each function they wish to use and BusyBox
           will act like whatever it was invoked as!
   
   Currently defined functions:
           [, [[, ash, basename, cat, chgrp, chmod, chown, chroot, cmp, cp,
           cpio, cttyhack, cut, date, dd, depmod, devmem, df, dirname, dmesg,
           du, echo, egrep, env, expr, false, fdisk, fgrep, find, grep, gunzip,
           gzip, halt, head, hostname, hush, ifconfig, insmod, kill, killall,
           ln, login, ls, lsmod, md5sum, mdev, mkdir, mknod, modprobe, more,
           mount, msh, mv, netstat, ping, pivot_root, poweroff, printf, ps,
           pwd, reboot, rm, rmdir, rmmod, route, rx, sed, setconsole, setsid,
           sh, sleep, stty, sync, tail, tar, telnetd, test, tftp, top, tr,
           true, udhcpc, umount, unzip, usleep, uudecode, uuencode, vi, wget,
           xargs, yes, zcat

Also on the initrd are the TS specific applications: sdctl, spiflashctl, nandctl, daqctl, ts7500ctl, canctl, and xuartctl. We also provide the ts7500.subr which provides the following functions:

 cvtime()
 usbload()
 sdsave()
 spiflashsave()
 save()
 sd2spiflash()
 spiflash2sd()
 setdiopin()
 getdiopin()
 setrelay()
 setout()
 getin()
 tshelp()
 gettemp()

To use these functions you must source the subr file:

. /ts7500.subr
## or from Debian 
# . /initrd/ts7500.subr
tshelp