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Diffstat (limited to 'docs/running-openadk.txt')
| -rw-r--r-- | docs/running-openadk.txt | 53 |
1 files changed, 37 insertions, 16 deletions
diff --git a/docs/running-openadk.txt b/docs/running-openadk.txt index dcfd7451d..205b0d292 100644 --- a/docs/running-openadk.txt +++ b/docs/running-openadk.txt @@ -60,8 +60,6 @@ OpenADK is generated while producing the +base-files+ package. The main job the default inittab does is to start the +/etc/init.d/rcS+ shell script, and start one or more +getty+ programs (which provides a login prompt). -Support for systemd and s6 is very experimental at the moment. - /dev management ~~~~~~~~~~~~~~~ @@ -73,19 +71,21 @@ hardware devices, even if they are properly recognized by the Linux kernel. In OpenADK you can choose between different types of device managements. -OpenADK defaults to *dynamic device nodes using devtmpfs and mdev*. This method -relies on the _devtmpfs_ virtual filesystem in the kernel, which is enabled by -default for all OpenADK generated kernels, and adds the +mdev+ userspace -utility on top of it. +mdev+ is a program part of Busybox that the kernel will -call every time a device is added or removed. Thanks to the +/etc/mdev.conf+ -configuration file, +mdev+ can be configured to for example, set specific -permissions or ownership on a device file, call a script or application -whenever a device appears or disappear, etc. Basically, it allows _userspace_ -to react on device addition and removal events. +mdev+ is also important if you -have devices that require a firmware, as it will be responsible for pushing the -firmware contents to the kernel. +mdev+ is a lightweight implementation (with -fewer features) of +udev+. For more details about +mdev+ and the syntax of its -configuration file, see http://git.busybox.net/busybox/tree/docs/mdev.txt. +OpenADK defaults to *static device nodes using devtmpfs*. That is the simplest +way available. Most users might like to change it to *dynamic device nodes +using devtmpfs and mdev*. This method relies on the _devtmpfs_ virtual +filesystem in the kernel, which is enabled by default for all OpenADK generated +kernels, and adds the +mdev+ userspace utility on top of it. +mdev+ is a +program part of Busybox that the kernel will call every time a device is added +or removed. Thanks to the +/etc/mdev.conf+ configuration file, +mdev+ can be +configured to for example, set specific permissions or ownership on a device +file, call a script or application whenever a device appears or disappear, etc. +Basically, it allows _userspace_ to react on device addition and removal +events. +mdev+ is also important if you have devices that require a firmware, +as it will be responsible for pushing the firmware contents to the kernel. ++mdev+ is a lightweight implementation (with fewer features) of +udev+. For +more details about +mdev+ and the syntax of its configuration file, see +http://git.busybox.net/busybox/tree/docs/mdev.txt. initscripts ~~~~~~~~~~~ @@ -179,8 +179,29 @@ In both cases the default user is +root+ and the default password is either via +passwd+ on the system or you can preconfigure a password via +make menuconfig+ under +Runtime configuration+. -The default shell used in OpenADK is +mksh+ from http://www.mirbsd.org/mksh/. +The default shell used in OpenADK is +mksh+ from http://www.mirbsd.org/mksh.htm. You can change the shell in +make menuconfig+ under +Runtime configuration+. Be aware of the fact that the bootup process might use some +mksh+ features to speedup the system start. When you change the shell for system +/bin/sh+ the slower startup is used as a fallback. + +analyzing logs +~~~~~~~~~~~~~~ + +Since embedded systems usually avoid writing continously on non-volatile storage +(to avoid waer-out of the storage device) there are no logfiles under /var/log and +/var itself is mapped onto a RAM based filesystem. + +Instead the syslog daemon logs into a ciruclar memory +buffer. The size of the memory buffer is by default 32KiB and can be changed in the +busybox configuration. + +To access the content of the buffer the +logread+ utility is used to dump the buffer. +To get a continous output of the logbuffer -f has to be added as option. + +--------------------- +Usage: logread [-fF] + +-f Output data as log grows +-F Same as -f, but dump buffer first +--------------------- |