Migrating from ARMLINK to LD script with overlays

I have a app.sct ARMLINK script file with overlay section:

OVERLAY_A ImageLimit(RAM_DATA_ON) OVERLAY
{
    *(.app.overlay_a)
}

I'm trying to achive the same result with gcc linker script as follows:

OVERLAY SIZEOF(RAM_DATA_ON) : 
{
    OVERLAY_A 
    {
            *(.app.overlay_a)
    }
}

ARMLINK automatically defines these symbols for overlay section:

Image$$OVERLAY_A$$ZI$$Length

Image$$OVERLAY_A$$RW$$Length

Image$$OVERLAY_A$$RO$$Length

Image$$OVERLAY_A$$RW$$Base

Image$$OVERLAY_A$$RO$$Base

Load$$OVERLAY_A$$RW$$Base

Load$$OVERLAY_A$$RO$$Base

which are actively used by application.

How to correctly define these in ld script file overlay? How do I get RO, RW, ZI parts from .app.overlay_a input section?