File list (Check if you may need any files):
os20
....\alarm
....\.....\alarm.c
....\.....\alarmi.h
....\.....\alarm_c.c
....\.....\makefile
....\.....\mgr.c
....\bldenvpc.cx
....\bldenvpc.tp
....\buildenv.cx
....\buildenv.tp
....\buildlnx.cx
....\c1
....\..\c1i.h
....\..\kernel.c
....\..\ksuspend.c
....\..\ktimeslice.c
....\..\makefile
....\..\run_a.c
....\..\start.c
....\..\suspendr.S
....\c2c4
....\....\hw.c
....\....\kernel.c
....\....\kerni.h
....\....\kernvars.c
....\....\kern_cpp.c
....\....\ksuspend.c
....\....\makefile
....\....\move2d.c
....\....\run_a.c
....\....\start.c
....\....\suspendr.S
....\....\switch.c
....\....\trap.c
....\cache
....\.....\c1_c100.c
....\.....\c2_c200.c
....\.....\cachei.h
....\.....\config.c
....\.....\disabl_d.c
....\.....\disabl_i.c
....\.....\enable_d.c
....\.....\enable_i.c
....\.....\flush_d.c
....\.....\init_c.c
....\.....\inval_d.c
....\.....\inval_i.c
....\.....\lock.c
....\.....\makefile
....\.....\nocache.c
....\.....\st20dc1.c
....\.....\st20tp3.c
....\.....\start.c
....\.....\status.c
....\.....\sti5500.c
....\.....\sti5510.c
....\.....\sti5512a.c
....\.....\sti5512b.c
....\.....\vars.c
....\chan
....\....\alt.c
....\....\chani.h
....\....\channel.c
....\....\chan_c.c
....\....\chan_i.c
....\....\fail.c
....\....\list.c
....\....\makefile
....\....\unlink.c
....\clib
....\....\errno.c
....\....\heap.c
....\....\makefile
....\clibprot
....\........\clibprot.c
....\........\debprot.c
....\........\deviceprot.c
....\........\dinkumprot.c
....\........\ehprot.c
....\........\ehthread.c
....\........\genericcppprot.c
....\........\genericprot.c
....\........\heapprot.c
....\........\makefile
....\........\stdioprot.c
....\device
....\......\id.c
....\......\makefile
....\......\name.c
....\include
....\.......\alarm.h
....\.......\c1regs.h
....\.......\c1timer.h
....\.......\c1timeri.h
....\.......\c2c4regs.h
....\.......\cache.h
....\.......\callback.h
....\.......\calli.h
....\.......\chan.h