TweetFollow Us on Twitter

SimpleAPP
Volume Number:10
Issue Number:4
Column Tag:Demonstration

Building The SimpleAPP Demonstration Application

By Richard Clark

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

Even though a program written for a Power Macintosh can use the same source code as a 68K Macintosh, the build process is different. Power Macintosh development uses a new set of compilers and linkers, and introduces the first fundamentally new Macintosh development system in several years - Metrowerks’ “Code Warrior.”

Not only are the tools different, but “native” Power Macintosh executables use a different format than 68K executables. “Native” application code is stored in the data fork of a file, and requires a ‘cfrg’ resource to notify the system that PowerPC code is present. The ‘cfrg’ resource describes several major things about the fragment or fragments in the current file:

• Code type (only PowerPC is supported at present)

• Whether this is a stand-alone fragment, or an overpatch to another fragment

• Version information for this fragment

• Is this a library or an application? (There’s also a value for “is a drop-in”, but the system only looks for ‘cfrg’ resources in applications and shared libraries. The third value is supplied for applications which include cfrg resources in their extensions and parse these resources directly. The “ModApp” sample included with both the MetroWerks and Apple development environments includes a cfrg parser.)

• Is this on disk, or in memory? (An additional value, “on disk segmented” is reserved for future use.)

• If this is on disk, what is the offset to the start of the container? This allows applications to reserve the first part of the data fork for application-specific information (though Apple is discouraging developers from writing to the data fork of a running application.) Also, what is the length of the container.

These two fields serve another purpose besides allowing an application to store information in the data fork - the data fork may contain multiple containers, and the associated ‘cfrg’ resource may have an entry for each container.

• The name of this fragment. This is especially important for shared libraries as it allows the name of a shared library to be independent from the name of its file. If the user renames a shared library, nothing will break. This also supports packing multiple fragments into the same file as described above.

• If this is an application, the stack size (or 0 for the default.) Also, the “appSubFolderID” field can be used if an application maintains a folder full of shared libraries. The application can include an ‘alis’ folder alias resource in its resource fork, and place the ID number of that resource into the cfrg.

This resource has to be added as part of the build process.

Building with Code Warrior

SimpleApp is easy to build with code warrior, though you have to set the appropriate ‘cfrg’ and ‘SIZE’ resource values in the Preferences Dialog. Code Warrior accepts only a subset of the ‘cfrg’ information at present (whether this is an application or a Shared Library, the fragment’s name, and the default stack size), but these are adequate for our purposes.

Building the SimpleApp code resources is a bit more interesting. You have to specify that you are building a stand-alone module and set the file’s type and creator. (This type and creator indicates to SimpleApp that this is disk-based code.)

The other important setting specifies the code’s main entry point, initialization, and termination routines. In an application, these routines (typically called __start, __initialize, and __terminate) are supplied by the runtime library. Since our code resource has its own special routines, those names must be supplied to the “Linker” part of the Preferences Dialog.

If you’re building disk-based code, that’s all you have to do. If you want to create resource-based code, SimpleApp comes with an auxiliary application (DataToRes) which will take a SimpleApp ‘DPEF’ file (with code in the data fork) and turn it into a ‘RPEF’ file with code in a ‘RPEF’ resource.

Building with MPW

SimpleApp also comes with a MPW makefile. Building the application and the external code is a simple matter of compiling and linking, with one complication. The compiler and linker emit code in the XCOFF (Extended Common Object File Format) used by IBM, but the Power Macintosh prefers PEF. The Macintosh on RISC SDK supplies a “MakePEF” tool to convert XCOFF to PEF. When you run this tool, you must supply not only the file to be converted, but also a set of “library name mapping” rules that remove the “.xcoff” extension from the shared library names:


/* 1 */
SimpleApp ƒƒ SimpleApp.xcoff
 MakePEF SimpleApp.xcoff -o {targ} 
 -l InterfaceLib.xcoff=InterfaceLib

Another option to MakePEF lists the Main, Initialization, and Termination routines. (If the “main” routine was specified to the linker, it doesn’t have to be supplied to MakePEF.)


/* 2 */
'PICT Viewer' ƒƒ PICTViewer.xcoff
 MakePEF {deps} -o {targ} 
 -i OurInitRoutine -t OurTerminationRoutine 
 -l InterfaceLib.xcoff=InterfaceLib

The PowerPC linker performs dead code stripping, so you have to tell the linker to retain the Initialization and Termination routines. You can do this with the “-dead off” option, or by exporting the Initialization and Termination routines:


/* 3 */
PICTViewer.xcoff ƒ PICTViewer.c.o {XCOFFLibs}
 PPCLink {deps} -o {targ} -main OurMainRoutine -sym {SYM} 
 -export OurInitRoutine,OurTerminationRoutine

Finally, just as Code Warrior creates code in the data fork, so does MakePEF. This could create a problem if you wanted to create resource-based code, but MPW users can use a “Rez” script to read a PEF file into a resource:


/* 4 */
// File: Chaos.r
//
// This file includes the resources from a resource file
// (Unlike SimpleApp, an external don't need a 'cfrg' or
// 'SIZE' resource)

read 'RPEF' (128) "Chaos.PEF";







  
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

The best scanner app on mobile
People always say that the best camera is the one you have with you. Well, the same is true with scanners, and your phone can be a pretty great tool for scanning receipts and other documents while you're on the go. [Read more] | Read more »
MARVEL Avengers Academy guide - How to g...
MARVEL Avengers Academy lets you build your own superhero school and fill it with heroes from the Marvel universe. It can be a little slow going to get your school's attendance up though, so we've gathered together somesome tips to help you do this... | Read more »
Shadow Blade: Reload guide - How to hack...
Shadow Blade: Reload is the kind of action-platformer that would have happily sucked up hours of your time on a console a few years back.Now, you can take it with you wherever you go, and its mobile conversion is not too shabby at all. To help you... | Read more »
Tomb of the Mask guide - How to increase...
Tomb of the Mask is a great endless arcade game from Happymagenta in which quick reflexes and a persistent attitude can go a long way toward earning a top score. Check out these tips to see if you can give yourself an edge on the leaderboards. [... | Read more »
Smooth Operator! (Games)
Smooth Operator! 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Smooth Operator is a weird, weird two-player kissing game. Squeeze in for 2 player fun on a single iPad, creating awkward... | Read more »
Sinless: Remastered (Games)
Sinless: Remastered 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: | Read more »
_PRISM Guide - How to solve those puzzle...
_PRISM is a rather delightful puzzle game that’s been tailor made for touch screens. While part of the fun is figuring things out as you go along, we thought we’d offer you a helping hand at getting in the right mindset. Don’t worry about messing... | Read more »
Fractal Space (Games)
Fractal Space 1.3.1 Device: iOS Universal Category: Games Price: $.99, Version: 1.3.1 (iTunes) Description: Live the memorable experience of Fractal Space, a unique first person adventure & puzzle game by Haze Games! Will you... | Read more »
Set off on an adventure through the Cand...
Like match three puzzlers? If so, Jelly Blast, the innovative iOS and Android game which launched last year, is worth a look. Jelly Blast sees you head off on an epic adventure through the Candy Kingdom with your friends Lily, Mr. Hare, and Mr.... | Read more »
Ellipsis - Touch. Explore. Survive. (...
Ellipsis - Touch. Explore. Survive. 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »

Price Scanner via MacPrices.net

cb Hardcase – Handmade and Premium Protective...
Baden-Baden, Germany based company cb innovations has introduced the new cb Hardcase for iPhone. Featuring fine Italian Premium leather that makes for a unique look and feel, the cb Hardcase... Read more
Sale! B&H Photo offers 12-inch Retina Mac...
B&H Photo has 12″ Retina MacBooks on sale for $300 off MSRP for a limited time. Shipping is free, and B&H charges NY tax only: - 12″ 1.1GHz Gray Retina MacBook: $999 $300 off MSRP - 12″ 1.... Read more
App Annie Reveals Future of the App Economy:...
App Annie, a San Francisco based mobile app data and insights platform, has launched its first comprehensive app economy forecast. This new offering will provide brands, agencies, investors and app... Read more
Apple restocks Certified Refurbished Mac mini...
Apple has restocked Certified Refurbished 2014 Mac minis, with models available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz Mac mini: $419 $... Read more
What iPad Pro Still Needs To Make It Truly Pr...
I love my iPad Air 2. So much that I’m grudgingly willing to put up with its compromises and limitations as a production tool in order to take advantage of its virtues. However, since a computer for... Read more
21-inch 3.1GHz 4K on sale for $1399, $100 off...
B&H Photo has the 21″ 3.1GHz 4K iMac on sale $1399 for a limited time. Shipping is free, and B&H charges NY sales tax only. Their price is $100 off MSRP: - 21″ 3.1GHz 4K iMac (MK452LL/A): $... Read more
Apple price trackers, updated continuously
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: - 15″... Read more
Save up to $240 with Apple Certified Refurbis...
Apple is now offering Certified Refurbished 12″ Retina MacBooks for up to $240 off the cost of new models. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The... Read more
Apple refurbished 13-inch Retina MacBook Pros...
Apple has Certified Refurbished 13″ Retina MacBook Pros available for up to $270 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz... Read more
Apple refurbished Time Capsules available for...
Apple has certified refurbished Time Capsules available for $120 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $179, $120 off - 3TB... Read more

Jobs Board

Infrastructure Engineer - *Apple* /Mac - Rem...
…part of a team Requires proven problem solving skills Preferred Additional: Apple Certified System Administrator (ACSA) Apple Certified Technical Coordinator (ACTC) Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Simply Mac *Apple* Specialist- Service Repa...
Simply Mac is the largest premier retailer of Apple products in the nation. In order to support our growing customer base, we are currently looking for a driven Read more
*Apple* Reporter - Business Insider, Inc. (U...
Business Insider is looking for a reporter to cover Apple , the biggest and arguably most important company in tech. As our primary Apple reporter, you will: * Read more
Infrastructure Engineer - *Apple* /Mac - Rem...
…part of a team Requires proven problem solving skills Preferred Additional: Apple Certified System Administrator (ACSA) Apple Certified Technical Coordinator (ACTC) Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.