example folio

Folios are a form of dynamically loaded shared libraries. Similar to dlopen on Unix but instead of loading individual functions you load the a collection of functions. Folios can contain both "user" and "privilaged" (SWI) functions.

3DO did not advertise the existence Folios besides how to use the ones they created. In early revisions of the official SDK you can find a simple example showing how to build a folio but strictly for user space functions. However, the example was incomplete and later removed.

Using the Portfolio OS source we have pieced together how to build a proper Folio allowing for both user and SWI functions. With SWI functions it is possible to interact with the hardware directly.

As seen in the Makefile it is necessary to:

• Give the file the extension .privfolio if using privileged features.
• Sign with 3DO key.
• Set the executable's flags to 2 (to indicate it is to run privileged).
• Set the executable's folio subtype to 1 (KERNELNODE).
• Set the executable's node type to 4 (FOLIONODE).
• Set the executable's name to match that of the Folio name used in the code.

Building

1. Get 3do-devkit
2. source 3do-devkit/activate-env
3. make
4. make install will install the header and library into 3do-devkit