I checked out the vxworks branch (commit 18ac6b0, the last one on that branch) and tried to build ML for the 40D.
I am on Win7 + Cygwin at the moment and did:
cd platform/40D.111
make zip
Many modules were not built, other modules had comments such as "Will not load on 40D".
In the end I have a zip named magiclantern-Nightly.2019Jul28.40D111.zip containing, among the rest, the following modules:
$ ls -l
total 1028
-rwxr-xr-x 1 ... 33118 Jul 28 15:58 40D_111.sym
-rwxr-xr-x 1 ... 21828 Jul 28 16:03 adv_int.mo
-rwxr-xr-x 1 ... 11816 Jul 28 16:03 arkanoid.mo
-rwxr-xr-x 1 ... 17800 Jul 28 16:03 autoexpo.mo
-rwxr-xr-x 1 ... 18068 Jul 28 16:03 bench.mo
-rwxr-xr-x 1 ... 7632 Jul 28 16:03 deflick.mo
-rwxr-xr-x 1 ... 11636 Jul 28 16:03 dot_tune.mo
-rwxr-xr-x 1 ... 15488 Jul 28 16:03 dual_iso.mo
-rwxr-xr-x 1 ... 324544 Jul 28 16:03 edmac.mo
-rwxr-xr-x 1 ... 28240 Jul 28 16:03 ettr.mo
-rwxr-xr-x 1 ... 14600 Jul 28 16:03 file_man.mo
-rwxr-xr-x 1 ... 304104 Jul 28 16:03 lua.mo
-rwxr-xr-x 1 ... 42224 Jul 28 16:03 mlv_lite.mo
-rwxr-xr-x 1 ... 44372 Jul 28 16:03 mlv_play.mo
-rwxr-xr-x 1 ... 62596 Jul 28 16:03 mlv_rec.mo
-rwxr-xr-x 1 ... 5772 Jul 28 16:03 pic_view.mo
-rwxr-xr-x 1 ... 30576 Jul 28 16:03 raw_rec.mo
-rwxr-xr-x 1 ... 22028 Jul 28 16:03 silent.mo
This is my very first attempt to build ML: would you please let me know if I'm on the right track, or is there anything evidently broken?
I have disassembled my ROM dump, my next step would be trying to understand more about stubs...