[ArtiiP]

well it's not that hard

Changing end of koreader\frontend\device\pocketbook\device.lua
to somthing like this:

local PocketBook840 = PocketBook:new{
    isTouchDevice = no, -- yes,
    hasKeys = yes,
    display_dpi = 200,
    emu_events_dev = "/var/dev/shm/emu_events",
}

function PocketBook840:init()
    self.screen = require("ffi/framebuffer_mxcfb"):new{device = self, debug = DEBUG}
    self.powerd = require("device/pocketbook/powerd"):new{device = self}
    self.input = require("device/input"):new{
        device = self,
        event_map = {
            [24] = "LPgBack",
            [25] = "LPgFwd",
            [1002] = "Power",
            [0x11] = "Up",
            [0x12] = "Down",
            [0x13] = "Back", --"Left",
            [0x14] = "Menu", -- "Right",
            [0x0a] = "Press" , -- "Menu","Press" , "Home", "ScreenKB", "Enter"
        }
    }
    PocketBook.init(self)
end

i got usable (but unstable) menus on 515.