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

Pocket Arcade Story (Games)
Pocket Arcade Story 1.00 Device: iOS Universal Category: Games Price: $4.99, Version: 1.00 (iTunes) Description: Here comes a new challenger: it's the arcade simulation game you've been waiting for! Build your very own gaming... | Read more »
How to get coins faster in Rodeo Stamped...
There comes a time in a cowboy or cowgirl's life when all the riding and lassoing skills in the world aren't enough. You're going to need some cold, hard cash to keep your sky zoo expanding in Rodeo Stampede. [Read more] | Read more »
How to out-do Cam Newton in Can You Dab?
The thing about dance crazes is that you're never really sure when they've run their course. Take the Dab, for instance. Propelled by its adoption as the touchdown celebration of choice for Carolina Panthers quarterback Cam Newton, the Dab seemed... | Read more »
Artik Games releases Splashy Cats for An...
Splashy Cats had us hooked from the title alone, and when we found out the game was literally just zig-zagging one of our favourite pop-culture references, guised as a playable cat character, down a river – our appetites were whetted to say the... | Read more »
Battle Cars (Games)
Battle Cars 1.1 Device: iOS Universal Category: Games Price: $1.99, Version: 1.1 (iTunes) Description: Welcome to the world of Battle Cars. Battle Cars is a classic arcade top-down racing game with fast mini cars and funny weapons to... | Read more »
How to get started with live.ly
One could be forgiven for thinking that there are already plenty of streaming video apps out there. It's just that the App Store charts would insist that you're mistaken. [Read more] | Read more »
Rodeo Stampede: Guide to all Savannah an...
A "gotta catch 'em all" joke seems appropriate here, even though we're talking animals in Rodeo Stampede and not pocket monsters. By now you've probably had plenty of rides, tamed some animals and built yourself a pretty nice zoo | Read more »
Is there cross-platform play in slither....
So you've sunken plenty of hours into crawling around in slither.io on your iPhone or iPad. You've got your stories of tragedy and triumph, the times you coiled four snakes at one time balanced out by the others when you had a length of more than... | Read more »
Rodeo Stampede guide to running a better...
In Rodeo Stampede, honing your skills so you can jump from animal to animal and outrun the herd as long as possible is only half the fun. Once you've tamed a few animals, you can bring them home with you. [Read more] | Read more »
VoxSyn (Music)
VoxSyn 1.0 Device: iOS Universal Category: Music Price: $6.99, Version: 1.0 (iTunes) Description: VoxSyn turns your voice into the most flexible vocal sound generator ever. Instantly following even subtle modulations of pitch and... | Read more »

Price Scanner via MacPrices.net

Save up to $600 with Apple refurbished Mac Pr...
Apple has Certified Refurbished Mac Pros available for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The following... Read more
21-inch 2.8GHz iMac on sale for $1199, save $...
Amazon has the 21″ 2.8GHz iMac (model #MK442LL/A) on sale for $1199.99 including free shipping. Their price is $100 off MSRP, and it’s the lowest price available for this model. Read more
13-inch 2.5GHz MacBook Pro (Apple refurbished...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more
MacBook Airs on sale for up to $50-$100 off M...
B&H Photo has 13″ and 11″ MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 1.6GHz/128GB MacBook Air: $849 $50 off list price - 11″ 1.... Read more
Brexit Vote Result Forecast To Slash UK 2016...
Uncertainty and economic volatility can be expected to increase over the next nine months, as the Brexit and concerns over the future of the EU hit IT investment, say Canalys market analysts, with... Read more
13-inch 256GB MacBook Air on sale for $1149,...
Amazon has the 2016 13″ 1.6GHz/256GB MacBook Air (model MMGG2LL/A) on sale for $1149.99 including free shipping. Their price is also $50 off MSRP. Read more
Haven App Launches New Age Of Wirless 911 Eme...
Haven from RapidSOS represents a transformation in access to emergency services from a phone call solely dependent on voice to a robust data connection for voice, text, medical/demographic data.... Read more
Cu Parachute 1.1 Retirement Success PLanning...
Tucson, Arizona based Indie developer Bradley McCarthy has announce the release of Cu (Copper) Parachute 1.1 for iPhone, iPad, and iPod touch devices — a tool with which users can continuously... Read more
Research and Markets Releases iPhone 6s Plus...
A new analysis report from Dublin-based Research and Markets observes that with the iPhone 6s Plus, Apple introduced a new rear camera module. The new device has similar structure and technology than... Read more
Apple refurbished Retina MacBook Pros availab...
Apple has Certified Refurbished 2015 13″ and 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free... Read more

Jobs Board

*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
*Apple* Retail - Multiple Positions, Willow...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
*Apple* iPhone 6s and New Products Tester Ne...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.