Top level multishell/bios override

-- Begin
parentTerm.clear()
setMenuVisible( false )
selectProcess( launchProcess( {
    ["shell"] = shell,
    ["multishell"] = multishell,
}, "/rom/programs/shell" ) )
redrawMenu()
-- Run processes
while #tProcesses > 0 do
    -- Get the event
    local tEventData = { os.pullEventRaw() }
    local sEvent = tEventData[1]
    if sEvent == "term_resize" then
	    -- Resize event
	    w,h = parentTerm.getSize()
	    resizeWindows()
	    redrawMenu()
    elseif sEvent == "char" or sEvent == "key" or sEvent == "paste" or sEvent == "terminate" then
	    -- Keyboard event
	    -- Passthrough to current process
	    resumeProcess( nCurrentProcess, unpack( tEventData ) )
	    if cullProcess( nCurrentProcess ) then
		    setMenuVisible( #tProcesses >= 2 )
		    redrawMenu()
	    end
    elseif sEvent == "mouse_click" then
	    -- Click event
	    local button, x, y = tEventData[2], tEventData[3], tEventData[4]
	    if bShowMenu and y == 1 then
		    -- Switch process
		    local tabStart = 1
		    for n=1,#tProcesses do
			    tabEnd = tabStart + string.len( tProcesses[n].sTitle ) + 1
			    if x >= tabStart and x <= tabEnd then
				    selectProcess( n )
				    redrawMenu()
				    break
			    end
			    tabStart = tabEnd + 1
		    end
	    else
		    -- Passthrough to current process
		    resumeProcess( nCurrentProcess, sEvent, button, x, (bShowMenu and y-1) or y )
		    if cullProcess( nCurrentProcess ) then
			    setMenuVisible( #tProcesses >= 2 )
			    redrawMenu()
		    end
	    end
    elseif sEvent == "mouse_drag" or sEvent == "mouse_scroll" then
	    -- Other mouse event
	    local p1, x, y = tEventData[2], tEventData[3], tEventData[4]
	    if not (bShowMenu and y == 1) then
		    -- Passthrough to current process
		    resumeProcess( nCurrentProcess, sEvent, p1, x, (bShowMenu and y-1) or y )
		    if cullProcess( nCurrentProcess ) then
			    setMenuVisible( #tProcesses >= 2 )
			    redrawMenu()
		    end
	    end
    else
	    -- Other event
	    -- Passthrough to all processes
	    local nLimit = #tProcesses -- Storing this ensures any new things spawned don't get the event
	    for n=1,nLimit do
		    resumeProcess( n, unpack( tEventData ) )
	    end
	    if cullProcesses() then
		    setMenuVisible( #tProcesses >= 2 )
		    redrawMenu()
	    end
    end
    if bWindowsResized then
	    -- Pass term_resize to all processes
	    local nLimit = #tProcesses -- Storing this ensures any new things spawned don't get the event
	    for n=1,nLimit do
		    resumeProcess( n, "term_resize" )
	    end
	    bWindowsResized = false
	    if cullProcesses() then
		    setMenuVisible( #tProcesses >= 2 )
		    redrawMenu()
	    end
    end
end