Difference between revisions of "J1939"
m (→Sources: Update sources to github) |
(→Build: update examples to github sources) |
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$ git clone <yourfavoritelinuxkernel> linux | $ git clone <yourfavoritelinuxkernel> linux | ||
$ cd linux | $ cd linux | ||
− | $ git remote add j1939 git:// | + | $ git remote add j1939 git://github.com/kurt-vd/linux |
$ git remote update j1939 | $ git remote update j1939 | ||
$ git merge j1939/j1939-vX.X | $ git merge j1939/j1939-vX.X | ||
Line 43: | Line 43: | ||
=== Build can-j1939-utils (recommended) === | === Build can-j1939-utils (recommended) === | ||
− | $ git clone git:// | + | $ git clone git://github.com/kurt-vd/can-utils |
− | $ cd can | + | $ cd can-utils |
$ make etc. | $ make etc. | ||
Line 54: | Line 54: | ||
=== Build iproute2-j1939 (recommended) === | === Build iproute2-j1939 (recommended) === | ||
− | $ git clone git:// | + | $ git clone git://github.com/kurt-vd/iproute2 |
$ cd iproute2 | $ cd iproute2 | ||
$ git checkout j1939-vX.X | $ git checkout j1939-vX.X |
Revision as of 03:17, 21 April 2015
Contents
SAE J1939 in Linux
overview
See also on Wikipedia.
SAE J1939 defines a higher layer protocol on CAN. It implements a more sophisticated addressing scheme and extends the maximum packet size above 8 bytes. Several derived specifications exists, which differ from the original j1939 on the application level, like MilCAN, NMEA2000 and especially ISO-11783 (ISOBUS). This last one specifies the so-called ETP (Extended Transport Protocol) which is has been included in this implementation. This inclusion results in a maximum packet size of ((2^24)-1)*7 bytes
Specifications
- SAE J1939-21 : data link layer
- SAE J1939-81 : network management
- ISO 11783-6 : Virtual Terminal (Extended Transport Protocol)
Sources
Support for SAE J1939 in Linux consists of 3 parts:
You probably want all 3 components to get a J1939 linux node working. The J1939 specific code resides in dedicated branches.
The final goal is to have these source trees mainlined.
Build
Build the kernel (necessary)
$ git clone <yourfavoritelinuxkernel> linux $ cd linux $ git remote add j1939 git://github.com/kurt-vd/linux $ git remote update j1939 $ git merge j1939/j1939-vX.X $ make etc.
With j1939-vX.X the branch that matches the closest, but not higher, with your linux version.
Build can-j1939-utils (recommended)
$ git clone git://github.com/kurt-vd/can-utils $ cd can-utils $ make etc.
Or you may merge the j1939 changes into any other can-utils version. This should be fairly simple.
If the branch of linux-can-j1939 that you merged into your kernel was for version 3.7 or higher, use the j1939-v6 branch of can-j1939-utils.
Build iproute2-j1939 (recommended)
$ git clone git://github.com/kurt-vd/iproute2 $ cd iproute2 $ git checkout j1939-vX.X $ make etc.
With j1939-vX.X the branch that matches the closest, but not higher, with your linux version.
Or you may merge the j1939 changes into any other iproute2 version. This may be a little more complicated.
Getting Started with J1939
First get a can0 bus on your system.
$ modprobe vcan $ ip link add can0 type vcan $ ip link set can0 up
Now start j1939.
$ modprobe can-j1939 $ ip link set can0 j1939 on
Now you should be able to use can0 as a j1939 CAN device.