HelenOS sources
KC_LALT 101 uspace/drv/hid/adb-kbd/ctl.c [0x3a] = KC_LALT,
KC_LALT 122 uspace/drv/hid/atkbd/atkbd.c [0x11] = KC_LALT,
KC_LALT 157 uspace/drv/hid/usbhid/kbd/conv.c [0xe2] = KC_LALT,
KC_LALT 114 uspace/drv/hid/xtkbd/xtkbd.c [0x38] = KC_LALT,
KC_LALT 117 uspace/srv/hid/input/ctl/sun.c [0x13] = KC_LALT,
KC_LALT 161 uspace/srv/hid/input/input.c case KC_LALT:
KC_LALT 376 uspace/srv/hid/input/layout/cz.c case KC_LALT:
KC_LALT 49 uspace/srv/hid/input/stroke.c { KM_LALT, KC_LALT },
HelenOS homepage, sources at GitHub