CM-iGT: Linux: Mint

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Overview

  • Linux on CM-iGT is Linux Mint 17 LTS with full-featured MATE desktop environment
  • All necessary drivers and tools are already installed
  • Networking, sound, video acceleration, 2D and 3D graphics and other features work out of the box
Admolition note.png Features such as TPM and CAN are unsupported in this release

ATI Catalyst video driver

The proprietary ATI Catalyst video driver for Radeon HD 6250 GPU provides the following features:

  • GPU accelerated video decoding XvBA (X-video Bitstream Acceleration)
  • Dual-head support
  • Up to 1920x1200 at 60 Hz resolution
  • 1080p playback with media players that support XvBA (Kodi and VLC)

GPIO

GPIO interface on SB-iGT consists of 15 I/Os provided by AMD FCH (Fusion Controller Hub) and 8 I/Os by sio1007 Super I/O chip

  • The responsible kernel modules are gpio-fch and gpio-sio1007
  • The kernel modules uses the following pin naming convention:


GPIO pin naming convention on SB-iGT
GPIO name HW source Name on SB-iGT board Pin on SB-iGT board Notes
GPIO11 FCH FCH_GPIO11 P15-4
GPIO14 FCH FCH_GPIO14 P15-18
GPIO201 FCH FCH_GPIO201_S5 P15-29 Active in S0 and S5 power states
GPIO202 FCH FCH_GPIO202_S5 P15-31 Active in S0 and S5 power states
GPIO204 FCH FCH_GPIO204_S5 P15-33 Active in S0 and S5 power states
GPIO205 FCH FCH_GPIO205_S5 P15-35 Active in S0 and S5 power states
GPIO54 FCH FN2PW M_GPIO54 P14-11
GPIO56 FCH FNTH_GPIO56 P14-15
GPIO57 FCH FNTH1_GPIO57 P14-17
GPIO58 FCH FNTH2_GPIO58 P14-21
GPIO170 FCH AZ_SI3_GPIO170 P14-28
GPIO172 FCH TIN1_GPIO172 P14-5
GPIO173 FCH TIN1_GPIO173 P14-7
GPIO197 FCH TMR0_GPIO197 P14-4
GPIO198 FCH TMR0_GPIO198 P14-6
GPIO246 SIO1007 SIO_GPIO16 P15-5
GPIO247 SIO1007 SIO_GPIO17 P15-7
GPIO248 SIO1007 SIO_GPIO30 P15-9
GPIO249 SIO1007 SIO_GPIO31 P15-11
GPIO250 SIO1007 SIO_GPIO31 P15-13
GPIO251 SIO1007 SIO_GPIO33 P15-15
GPIO252 SIO1007 SIO_GPIO34 P15-14
GPIO253 SIO1007 SIO_GPIO35 P15-16


  • The GPIO sysfs interface allows users to manipulate any GPIO from userspace dynamically.
  • A basic example of GPIO usage (as root user):
$ modprobe fch_gpio
$ echo 11 > /sys/class/gpio/export
$ echo out > /sys/class/gpio/gpio11/direction
$ echo 1 > /sys/class/gpio/gpio11/value
## at this point voltage measuring on P15-4 (FCH_GPIO11) should give 3.3V
$ echo 0 > /sys/class/gpio/gpio11/value
## at this point voltage measuring on P15-4 (FCH_GPIO11) should give 0.0V
$ echo 11 > /sys/class/gpio/unexport

Serial communication

  • COM1: Full modem control circuitry, baud rate from 30 bps to 250 Kbps, device node /dev/ttyS0
  • COM2: 2-wire, baud rate from 50 bps to 460 Kbps, device node /dev/ttyS1
  • Autologin from the serial console COM2 as root is enabled:

/etc/init/ttyS1.conf:

start on stopped rc RUNLEVEL=[2345]
stop on runlevel [!2345]

respawn
exec /sbin/getty -l /usr/bin/autologin -n -8 115200 ttyS1

/usr/bin/autologin (with chmod +x):

#!/bin/sh
exec /bin/login -f root
  • Connect your host PC to the COM2 on SB-iGT via the serial cable
  • Start terminal emulation on your host PC. Set baud rate to 115200 bps, 8 bit per frame, 1 stop bit, no parity, no flow control
  • As a result, you automatically login on CM-iGT as root

Watchdog

The AMD FCH supports a user configurable watchdog.

Once the watchdog is enabled the system restarts once the timeout period elapses, so in order to prevent it the user needs to either feed the watchdog or to disable it.

  • By default the timeout value is 60 sec and the watchdog deamon feeds the watchdog every 10 sec
  • The responsible kernel module is sp5100_tco
  • You can overwrite the default settings in /etc/watchdog.conf and /etc/default/watchdog
  • Watchdog is already installed and configured on the Linux image provided by CompuLab
  • As example you can simulate kernel panic (as root user):
$ echo c > /proc/sysrq-trigger
  • As a result, the watchdog is not fed and the system will reboot after 60 sec

CAN bus

  • currently unsupported


TPM

  • currently unsupported


See also