Setting home position using gcode

How do I set the current position to x=0,y=0,u=0,v=0 (hot wire machine....) using gcode ?  At this stage, I don't want to move the location, I just want to emulate setting home via the Axis home buttons

Try:

G10 L20 P0 X0 Y0 U0 V0

linuxcnc.org/docs/2.6/html/gcode/gcode.html#sec:G10-L20

That works - but only if the axes are already homed. I want to get rid of the need to home each axis separately in Axis when I start LinuxCNC. I will use GladeVCP to create a button to run the G10

So is there a way to emulate manually homing each axis using Axis?

You can set the home search velocity to zero in the INI file for any joints that you want to home where they are. But this means that you have no soft limits.

It's much better to actually home the axes, if you can.

I'm happy with homing the axes, I just want to add a button using gladevcp that will set all four once I have jogged the wire to where I want home to be. Not at all important, just being a bit pernickety

Try halui.home-all bit in  pin for requesting home-all (only available when a valid homing sequence is specified)