[coyotos-dev] Progress update

Jonathan S. Shapiro shap at eros-os.com
Mon May 28 19:28:59 EDT 2007

We seem overdue for a progress update. Some is good news!

Today, Coyotos ran a small, contrived, hand-crafted application far
enough to execute an illegal instruction and a breakpoint instruction.
This means that the page fault handling code is working for simple
cases, and the trap handling code is fairly well exercised. The rest of
the page fault logic is a Simple Matter Of Debugging. :-)

Particular credit on this is due to Jonathan Adams, who spent a fair bit
of time hitting his head with hammers to make this work.

If you have not had the pleasure of building your own OS, you may not
realize that this is a substantial accomplishment. In order to get this
far, an awful lot of the kernel has to be working.

The next few objectives, are (in order):

1. Perform a simple kernel capability invocation.
2. Perform a simple IPC
3. Deliver a fault message to a contrived keeper.
4. Perform a complex IPC
5. Finish implementing the individual capability types.

If you are inclined to count things, two metrics you might start keeping
track of are:

  Number of calls to "bug" in the kernel code base. (grep for 'bug('):

    Currently 41. Goal: 0. Number will go up and down for a while.
  Number of unimplemented kernel capability types: (grep for 'bug(',
    pipe to grep for '/cap_')

    Currently 15, Goal: 3 for embedded version

We're very close to switching to the core system application code. The
onus for the capability invocation code is on me (shap).


Jonathan S. Shapiro, Ph.D.
Managing Director
The EROS Group, LLC

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