HunkFix version 1.4 Friday August 31st, 1990 Copyright © 1990 Arthur Hagen THIS PROGRAM IS LIMITED DISTRIBUTABLE SHAREWARE =============================================== Disclaimer: There are NO warranties, either expressed or implied, with respect to the software, its quality, performance, or fitness for any particular purpose. This software is provided "as is" and the entire risk to its quality and performance is with the user. The author of this software shall NOT be liable for errors contained in the software or the software's documentation, or for incidental or consequential damages of any kind in connection with the performance, use or possession of same. This program is "ShareWare", i.e. if you find this program useful, the author would be immensely pleased to find a small cheque in his mailbox. The suggested sum to send is USD 10.00, but the amount could be whatever sum you would like to pay. I cannot develop for free, as I need to buy coffee, tobacco, harddisks etc. to wrestle more programs out of the Amiga. My address (for cheques, praise, bug reports etc.) is: Arthur Hagen Johan Scharffenbergsvei 99, apt 56 N-0694 OSLO 6 Norway, Europe My bank account: ABC Bank, Oslo, Norway (SWIFT code: UBNONOKKXXX) account no: /1600.52.26531 account name: Arthur Hagen This program is also "limited distributable". That means that you may give it away under certain conditions. The conditions are as follows: a) You may NOT charge the receiver any amount for the program itself. This means that if you are a PD vendor, you may still charge your customer for disks, P&P et al, but NOT per program. b) You may NOT remove this documentation file. This file, called HunkFix.DOC should be included either in the same directory, or in the same archive as the main program. c) You may NOT change either this file or the program file. This includes crunching, translating, changing text, etc. d) You may NOT include it along with any commercial programs, or as part of a bargain including such. HUNKS - AN INTRODUCTION ----------------------- The following information is useful, but not essential to the use of this program. If you already know about hunks, or don't bother to read all this, just skip to the next chapter. The Amiga computer performs what is called "scatter-loading" of all programs that is run. This means that programs most often consists of several small parts that can be loaded anywhere in memory. These smaller parts are referred to as "hunks". The different hunks in a program are joined together with some special information to form a loadable file. Most normal program files consists of these specific hunk types: Hunk_Header: Containing info about all other hunks. Hunk_Code : Containing executable code and/or data. Hunk_Data : Containing data. Hunk_BSS : Containing "uninitialized" data, i.e. data space that the program needs, but that isn't filled in before the program is run. This shortens the load file, although the same amount of memory is required to run the program. Hunk_End : Marking the end of other hunks. The Hunk_Data can also have BSS space appended to it at the end at load time. There may be zero or more of each hunk type, although (for obvious reasons) there must be at least one Hunk_Code present to run a program. There should also be only one Hunk_Header, and this should be located at the start of the program file. Since these hunks can be anywhere in memory, AmigaDOS provide means for the different hunks to know where hunks are located in memory. This info is appended after each hunk that needs it, and is called a "Reloc-hunk". Reloc is an abbreviation for "relocatable", and is called this because the scatter-loading demands that hunks may be placed anywhere in memory. There are six different types of reloc-hunks, of which three can be used in executable programs: Hunk_Reloc32: List of 32-bits modifications to be made to hunks. Hunk_Reloc16: List of 16-bits modifications to be made to hunks. Hunk_Reloc8 : List of 8-bits modifications to be made to hunks. The number specifies the number of bits the data is referenced by, so that a Reloc16 hunk will reference 16-bit data. As the Amiga has more than 64k of memory, 32-bits references are almost always used (16-bits can only address 64k), so we will most likely never see the Reloc16 and Reloc8 hunks used. The Hunk_Reloc32's tells AmigaDOS which hunks it should modify, and how to do it. To further increase chaos, there are three other commonly used hunks that we may encounter in a program file: Hunk_Name : Gives a name to the following hunk. This is not really useful for executable files, but is mainly used during program development. Hunk_Symbol: Contains information of the names that was used on data and program routines during program development. This is only useful for debugging a program (e.g. using WACK after a Guru). Hunk_Debug : Contains information that can be used by a debugger, but it is not very useful unless you have the same debugger as the guy who wrote the program. These three hunks are not needed to run a program, and may be removed if you don't want them. Two special hunk types you may see are: Hunk_Overlay: Specifies that the program should load in segments; that means the whole file will not be loaded at once, as one would usually expect. Instead some area of memory may be overwritten by a new part of the program. This hunk will then tell how to accomplish just this. Hunk_Break: Signifies the end of a Hunk_Overlay section. In addition to all these hunks, there are several more hunk types that may be encountered, but as these are of no concern here, they will not be covered by this manual. See the "AmigaDOS manual, Bantam Books" for further information. WHY HUNKFIX? ------------ When developing a program, developers usually use a "linker" to bind all pieces of the program together to form an executable file. As these linkers (and those who use them) are far from perfect, surplus information is often stored along with the file. We, the users, often get files that are bigger and crave for more memory than what is actually needed. The Lattice development tools often gives us programs that contain empty hunks, and the Manx development tools automatically adds 4 unused bytes to all programs, making the load file 16 bytes larger than necessary. HunkFix will try to remove the parts of load files that are not required to run a program, thereby making the program smaller. It will also try to rearrange the program parts so that "think time" during loading is reduced to a minimum. As HunkFix will remove all unused parts of a program, it can also be used to "chop" executable files that are received over modem. No guarantees are given, though. Note that HunkFix is NOT a cruncher or packer, and that HunkFix does NOT break any rules made by Commodore (as far as I know). This means that all programs that have been hunkfixed should function fine under all versions of the O/S and with no special requirements (i.e. if the programs would do so in the first place). But, as there is NO way to recover the original file from an hunkfixed one, consider keeping backups of the files. HOW TO USE HUNKFIX: ------------------- To use HunkFix on a program, you have to enter the CLI or Shell environ- ment of the Amiga. Then make sure that the file you want to fix really is a loadable file that is NOT crunched or written in BCPL. (You may use VScan by the same author to do this.) Then, if you decide to go on, use the following command: 1> HunkFix InFile [OutFile] Here "InFile" is the name of the file you want to fix, and "[OutFile]" is the optional name of the file to create. If you don't enter an OutFile parameter, the original file will be overwritten. NEVER DO THIS if you don't have a backup of the file! Even though HunkFix will work fine on almost all files, you MIGHT find files that won't function properly after HunkFix has been employed on them. These files are most probably not written after Commodore's specifications, but always keep backups of your programs no matter what. If you decide to stop HunkFix during execution, you may do so by holding the keys CTRL and C down. Entering "HunkFix ?" or just "HunkFix" will give you some short onscreen instructions. Some examples of files that HunkFix will optimize: C:Avail C:SetPatch most files in LIBS: (Yes, libraries are loadfiles!) most files written with Aztec C or Lattice C Itself :-) Some files that should NOT be HunkFixed: C:Install All files crunched with TurboImploder(TM) 3.0 Files made with MultiForth (TM). HOW HUNKFIX WORKS: ------------------ If commands are entered correctly, you will see something like this on screen: HunkFix version ?.?, ©1990 Arthur Hagen Loading file XXXX Filesize: ???? bytes Runsize: ???? bytes Program contains ?? hunks Pass 1 Hunk #0: ???? bytes Hunk_Code Hunk_Reloc32 Hunk_Symbol removed Hunk_End etc... Pass 2 Hunk #0: etc... Hunk total: ?? hunks Hunks used: ?? hunks Pass 3 Hunk #0: Reloc32 sorted Hunk #4: Reloc32 sorted Hunk #4: Reloc32 squeezed etc... Pass 4 Hunk #0: unchanged Hunk #1: unchanged Hunk #2: merged with hunk #1 Hunk #3: removed etc... Saving file YYYY Writing hunk #? Old filesize: ???? bytes New filesize: ???? bytes Task completed. HunkFix will first load the entire program into memory. If successful, it will then start working on the program in four passes. Pass 1: Here HunkFix will scan all hunks of the program to ensure that it recognizes them. In addition, Hunk_Name's, Hunk_Symbol's and Hunk_Debug's will be removed. Pass 2: Here HunkFix checks what hunks are actually needed to run the program, and mark those that are needed with the hunk number they will receive in later passes. Pass 3: Here HunkFix scans through all Hunk_Reloc32's, and sort their contents. If several Reloc32 sections can be joined together to save memory, this will also be done in this pass. Pass 4: HunkFix will now reshuffle the remaining hunks in the order that HunkFix established in pass 2. All empty hunks will be removed, and the first hunk to be loaded will always be hunk #0. If hunk #2 is a BSS hunk, and hunk #1 is a data-hunk, the BSS hunk will be merged with the latter. After these four passes, if the program was changed in any way, HunkFix will try to save the modified program hunk by hunk. You will receive a progress report while HunkFix is saving, and should any error occur, this will also be told. ERRORS: ------- You may find in certain cases that HunkFix aborts with an error message. These error messages are explained below: ***ERROR - Empty file! You have tried to use HunkFix on an empty file. Just delete the file instead. ***ERROR - Hunk_Overlay (segmented program), cannot touch it! Some programs may be written "segmented", i.e. they will not be loaded in full at once, but partwise as segments are needed. These files are more difficult to handle than others, and the current version of HunkFix will not do anything to them to avoid damage. ***ERROR - Unknown hunk: 0x???????? HunkFix covers only the most commonly used hunks, but if it finds a hunk that it doesn't recognize, it will abort with this error message. Note that some programs that are "crunched" to reduce size also will generate this error message. In this case it is most often because the crunched programs doesn't follow the normal Commodore-approved file format. The files themselves may run fine now, but maybe not under future versions of the operating system. ***ERROR - AmigaDOS error #??? If the AmigaDOS encounters an error during program execution, HunkFix will abort with this error message. Use 'Fault ???' to determine the exact cause of the error. Missspelling a filename or having a write-protected disk can lead to this error. Greeting to everyone that has bothered to read this far! *Art