when the joint beyond the soft limit, I want it can jog into the limits.

Hi, I am a new for linuxcnc redevelopment. I want to  implement this function. When machine homing, the joint exceeds the soft limit. I hope it can be homed normally and the joint can jog into the limits by the handwheel. How should I modify the source code ? 
Thank you sincerely!
 

It sounds you just just need to set homing up properly.

You can have the home switch outside the soft limits. After finding the home switch, LinuxCNC will move the amount you specify in the ini file.
You just need to set the correct values.

I want to implement my functionality from source. Thank you all the same.

It is not clear what you really want to do

pippin88 wrote:

It is not clear what you really want to do
 
I am sorry for my unclear expression. I will give an example.  The  [AXIS_X] MAX_LIMIT is -5  and the [JOINT_0] (which is belong to axis_x)MAX_LIMIT = -2. I have made it homed by modifying the code like the first picture. And then  I want to move the axis x into the limit by pin halui.axis.x.minus or the minus sign on the interface (which is shown as the second picture )so that is can work. I  think I should modify the code, but I don't know how to do. 
Thank you for your reply and help. 

I am sorry for my unclear expression. I give an example as follow. Thank you, it is very nice of you