FAQ

java command may not be for JRE.
Change setting by alternative.
# alternatives --install /usr/bin/java java /usr/java/default/bin/java 16023

#Change default setting alternatives --config java
#Show detailed list alternatives --display java

All the access to unit is via system CPU and direct access is not permitted.
Access to system CPU from Linux is through the MELSEC I/F sample Driver provided in BSP.

Shared memory is used for data transfer.

MELSEC I/F sample Driver in BSP enables access to peripheral unit.

The passwd command in BSP is a busybox package applet and links to/bin/busybox.
Furthermore, SETUID is not set in /bin/busybox, general user cannot change password of any user including his/her own.

$ passwd
passwd: must be suid to work properly
 

Use the setting below to allow changing own password to general user.

Note:

When setting SETUID bit in /bin/busybox, the following command is enabled for general user. (Within a command by default setting of BSP busybox.)

passwd / su

Refer to "Enable passwd command only" for such settings.

Set SETUID bit in /bin/busybox

How to set SETUID bit

1. Login as root

2. Set SETUID bit in /bin/busybox

# chmod 4755 /bin/busybox

Enable passwd command only

Have two busybox binaries and set SETUID bit to one of them

Copy busybox binary, set SETUID bit to one of the binaries and link passwd command to a busybox binary with SETUID bit.

Procedures

1. Login as root

2. Copy /bin/busybox

# cd /bin
# cp -a busybox busybox.suid

3. Set SETUID bit in /bin/busybox

# chmod 4755 /bin/busybox.suid

4. Recreate /sbin/passwd link

# cd /usr/bin
# rm -f passwd
# ln -s ../../busybox.suid passwd

It is possible in Linux, with some exceptional instance where system restart is required.
As to stand-alone user application, just restart application.

It cannot carry out any process beyond capability of ATOM processor (user CPU).
Also confirm necessary service and whether it is provided as BSP in advance.

Sorry! This information is only available for registered users.

Sorry! This information is only available for registered users.

Although Q24DHCCPU-LS BSP does not provide shutdown command, busybox has the poweroff/reboot command,
so use poweroff command to shutdown the target.

Japanese input is not supported.

Sorry! This information is only available for registered users.
 

Interrupt latency on Linux drastically changes depending on existing process at the point and their priorities.

Although latency has improved compared to previously adopted kernel, it may be necessary to use PreemptRT kernel or to modify driver depending on operational status considering the fact that periodic response is 10ms. However, necessity of these workaround must be determined by carrying out actual operation and validation.

The kernel BSP provides is not PreemptRT, so the PreemptRT Patch will be necessary to use it as PreemptRT.
Lineo is able to undertake customized development.

It depends on network driver to use. For C Controller module, the following driver is adopted and it supports jumbo frame as seen in the source code.

- Intel(R) PRO/1000 PCI-Express Gigabit Ethernet support

SD card is not mounted automatically, so manually mount after card insertion.
To mount an SD card, execute the following command.

ex) Mount the 1st partition of SD card

# mount /dev/mmcblk0p1 /mnt

Refer to the following article in Document: BSP Q24DHCCPU-LS Addendum for more details.

CHAPTER 8 INSTALLATION AND WIRING - 8.4 Inserting and Removing an SD Memory Card

If you use relevant Q24DHCCPU-LS (details below), installation procedures require some changes due to firmware function addition.

First five digits of serial number (on front and side of Q24DHCCPU-LS unit) "15082" and subsequent numbers.

To install Linux on relevant Q24DHCCPU-LS, power up the unit while holding the U EVENT button down.

*Until POWER lights up on power-supply unit.

Installation using ISO image is supported, so USB flash drive and SD card are also available.
Target boot via network (netboot etc.) or installation to the target using network are unsupported.
It is possible to start kernel (alone) from C Controller unit and have rootfs on a network though.

Deploy wizard guides how to install with USB CD-ROM drive, but if USB CD-ROM drive is not functional, use USB memory (or SD card) for installation.

Preliminary preparation

Install syslinux package to host OS, OR use isohybrid command.

*To acquire syslinux package, download from the following link or install by yum command.

syslinux package

Download and install

# rpm -i <download RPM>

Use yum command and install

# yum install syslinux

1. Execute up until "Booting Target Board" by Deploy Wizard.

Installation ISO is created at the following location.

<projectdir>/installcd.iso

2. Move to a project directory.

# cd <projectdir>

3. Update ISO file by using isohybrid command provided in syslinux package.

# isohybrid installcd.iso <= ISO file is overwritten.

4. Write updated ISO file to USB memory by using dd command.

# dd if=installcd.iso of=/dev/sdX oflag=direct bs=1M

5. Connect USB memory to the target.

6. Turn on the target while pressing U EVENT switch of C Controller module.

Target is started from USB memory and installation is carried out.

*It works the same for SD card. (Note that SDHC/SDXC card are not usable.)

*ISO file updated by isohybrid is installable with CD as well.

Yes. We perform operation check by jre-7u9-linux-i586.tar.gz.

VxWorks runs for system CPU and Linux runs for user CPU.