塞班(Symbian)安装文件.SISX文件格式说明

禄烨然
2023-12-01

原文地址:http://homepage.ntlworld.com/thouky/software/psifs/sis.html

 

用于分析SISX文件格式,解压SISX文件,压缩SISX文件,程序自动打包S60安装程序等.

 

 

SIS File Format

Version 1.18, 19-Dec-07
by Alexander Thoukydides (alex@thouky.co.uk)

 

Copyright © Alexander Thoukydides.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. A copy of the license is included in the section entitled " GNU Free Documentation License".

Introduction

The EPOC operating system uses files with a .SIS extension to allow easy installation of applications. These are usually produced using the makesis tool, and are handled by either the control panel Add/remove program or EPOC Connect. This document attempts to provide sufficient information to allow other software to be written that can decode and use SIS files.

The format of SIS files was changed in the Symbian OS version 9.1 release of Software Install. This document describes the original format used by earlier versions. Information about the restructured and redesigned format can be found at http://www.symbian.com/developer/techlib/papers/SymbianOSv91/softwareinstallsis.pdf.

The latest version of this document will normally be available from http://www.thouky.co.uk/software/psifs/sis.html.

History

RevisionDateAuthorDescription
1.1819-Dec-07Alexander ThoukydidesCorrected conditional expression types.
1.1727-Nov-07Alexander ThoukydidesCorrected size of the Number of certificates field.
1.1618-Jul-07Alexander ThoukydidesAdded standard names and other uses for the CRC algorithm.
1.1503-Feb-07Alexander ThoukydidesAdded note about endianness.
1.1423-Sep-06Alexander ThoukydidesAdded link to Symbian 9.1 SIS file format documentation.
1.1307-Jun-06Alexander ThoukydidesExclude signature block from calculation of the Checksum field.
1.1204-Apr-06Alexander ThoukydidesCorrected description of Original file length field.
1.1105-May-04Alexander ThoukydidesAdded long option codes.
1.1004-May-04Alexander ThoukydidesAdded more language and type codes.
1.0914-Mar-04Alexander ThoukydidesAdded more details of EPOC release 6 format files.
1.0830-Apr-03Alexander ThoukydidesAdded more details of EPOC release 6 format files.
1.0708-Jul-01Alexander ThoukydidesSplit the flags field into options and type.
Corrected installer version field.
1.0607-Jul-01Alexander ThoukydidesCorrected description of requisites with multiple language versions.
1.0530-Jun-01Alexander ThoukydidesAdded desription of checksum field in the header.
Explained calculation of UID4 better.
1.0427-Jun-01Alexander ThoukydidesAdded flags field to the file header.
1.0309-Jun-01Alexander ThoukydidesAdded missing languages and clarified some descriptions.
1.0202-Jun-00Alexander ThoukydidesReleased under version 1.1 of the GNU Free Documentation License.
1.0121-Apr-00Alexander ThoukydidesCorrected HTML.
Added URL for latest version of this document.
1.0027-Mar-00Alexander ThoukydidesFirst draft.

Disclaimer

This document is supplied "as is"; no warranty, express or implied, of the merchantability of this document or its fitness for any particular purpose is given. In no circumstances shall the author, or any provider or distributor of this document, be liable for any damage, loss of profits, or any indirect or consequential loss arising out of the use or misuse of any information or particular in this document.

All trademarks are acknowledged.

Acknowledgements

The information contained within this document was collated from many different sources, including (but not restricted to):

  • Jochen Siegenthaler's document providing a partial description of the SIS file format.
  • EPOC C++ SDK, Evaluation Edition.
  • Neuon's nSISUtil.
  • Analysis of a large selection of existing SIS files.
  • Andrew de Quincey's xmakesis Perl script, as updated by Rudolf Koenig.
  • Trial and error while developing PsiFS for RISC OS computers.
  • Corrections supplied by Dalibor Jelinek, Eberhard Mattes, Neil Masson, Stephanie Freitag, Bruno Tiago Rodrigues, Jimmy Shah, Jordan Walters, David Berry, Ren Yantao, a1z0r, Luca Cassioli, Wellu Mäkinen, Marcio Faustino and Tero Suomela.

Due to the diverse and incomplete nature of these sources, the description here probably contains both errors and omissions. Please send any corrections or additions to the author for inclusion in future revisions.

Sections

SIS files consist of the following sections:

Section
File Header
Language Records
File Records
Requisite Records
Component Name Record
Capabilities Record
Certificates Record
Resource Data

The sections are stored contiguously, without any padding or alignment. They should also normally be in the order listed, otherwise the residual SIS files may be larger than necessary.

Conventions

Unless otherwise specified the following conventions apply:

  • Numeric values larger than a byte are stored with the least significant byte first.
  • Strings are not terminated; their length is explicitly specified.
  • Pointers are specified as offsets from the start of the SIS file.

File Header

All SIS files start with a standard header:

OffsetBytesDescription
0x0004UID 1
0x0444UID 2
0x0884UID 3
0x0c124UID 4
0x10162Checksum
0x12182Number of languages
0x14202Number of files
0x16222Number of requisites
0x18242Installation language
0x1a262Installation files
0x1c282Installation drive
0x1e302Number of capabilities
0x20324Installer version
0x24362Options
0x26382Type
0x28402Major version
0x2a422Minor version
0x2c444Variant
0x30484Languages pointer
0x34524Files pointer
0x38564Requisites pointer
0x3c604Certificates pointer
0x40644Component name pointer

The header of EPOC release 6 format SIS files is extended:

OffsetBytesDescription
0x44684Signature pointer
0x48724Capabilities pointer
0x4C764Installed space
0x50804Maximum installed space
0x548416Reserved

The UID 1, UID 2 and UID 3 fields are the first three words of the file, and indicate the type of data it contains. UID 1 is the UID of the application to be installed, or 0x10000000 if none. UID 2 is 0x1000006D for EPOC releases 3, 4 and 5, and 0x10003A12 for EPOC release 6. UID 3 is always 0x10000419.

UID 4 is a checksum calculated from the preceding fields. The least significant 16 bits are given by the CRC16 of the bytes at even offsets from the start of the file, and the most significant 16 bits are given by the CRC16 of the bytes at odd offsets from the start of the file.

The Checksum field is calculated as the CRC16 of all the data in the SIS file excluding the 2 bytes occupied by the Checksum itself and any signature block. It is not updated for the residual SIS file.

The Number of languages and Languages pointer fields specify the number of languages supported by the SIS file and the offset to the languages records respectively.

The Number of files and Files pointer fields specify the number of files included in the SIS file and the offset to the files records respectively.

The Number of requisites and Requisites pointer fields specify the number of requisites specified in the SIS file and the offset to the requisites records respectively.

The Installation language and Installation files fields are both initially zero. When the SIS file is installed, these are modified with the settings used for the installation.

The Installation drive field is initially 0x0000 for EPOC releases 3, 4 and 5, and 0x0021 (the character code for "!") for EPOC release 6. When the SIS file is installed, this is modified with the setting used for the installation.

The Installer version field specifies the version of the Add/remove program required to handle the file. This is normally 68 (0x00000044) or 100 (0x00000064) for EPOC releases 3, 4 and 5, and 200 (0x000000c8) for EPOC release 6.

The Options may combine any of the following flags:

OptionCodeDescription
0x0001IU IsUnicode (EPOC release 5)
0x0002ID IsDistributable (EPOC release 5)
0x0008NCNOCOMPRESSNoCompress (EPOC release 6)
0x0010SHSHUTDOWNAPPSShutdownApps (EPOC release 6)

The Type may be any of the following:

TypeCodeDescription
0x0000SASISAPPContains an application (the default)
0x0001SYSISSYSTEMContains a shared/system component such as a DLL or OPX (EPOC release 6)
0x0002SOSISOPTIONContains an optional component, independently selectable by the user (EPOC release 6)
0x0003SCSISCONFIGConfigures an existing application or service (EPOC release 6)
0x0004SPSISPATCHPatches an existing component (EPOC release 6)
0x0005SUSISUPGRADEUpgrades an existing component (EPOC release 6)

The Major version and Minor version fields specify the version number of the application. The Minor version number is padded to two digits with leading zeros for display.

The Variant field is used when the component is a requisite for other components. If more than one variant of the requisite component exists for different machines then this field ensures that the correct variant is present. This is usually set to 0x00000000.

The Certificates pointer specifies the offset to the certificates record.

The Component name pointer field specifies the offset to the component name record.

The Signature pointer field specifies the offset to the signature block.

The Number of capabilities and Capabilities pointer fields specify the number of capabilities specified in the SIS file and the offset to the capabilities record respectively.

The Installed space field is initially 0x00000000. When the SIS file is installed, this is modified with the space used by the installed files.

The Maximum installed space field specifies the maximum space required for installation. This is usually the total size of all the files when uncompressed. If the SIS file contains alternates then the size of the larger alternate is used.

The Reserved field is for use by future revisions of the file format.

Cyclic Redundancy Check

The standard x16 + x12 + x5 + 1 polynomial is used with an initial remainder of zero to generate a 16 bit CRC. This is the CRC-16-CCITT algorithm (also known as CRC-CCITT), as used by the XMODEM, X.25, V.41, Bluetooth, PPP and IrDA protocols.

The following C code calculates a lookup table to allow efficient calculation of this CRC:

const unsigned int polynomial = 0x1021;
unsigned int table[256], index;
table[0] = 0;
for (index = 0; index < 128; index++)
{
    unsigned int carry = table[index] & 0x8000;
    unsigned int temp = (table[index] << 1) & 0xffff;
    table[index * 2 + (carry ? 0 : 1)] = temp ^ polynomial;
    table[index * 2 + (carry ? 1 : 0)] = temp;
}

The following line can then be used to add a byte (value) to a 16 bit CRC (old_crc) to give the new 16 bit CRC (new_crc):

new_crc = (old_crc << 8) ^ table[((old_crc >> 8) ^ value) & 0xff];

The CRC value should be initialised to 0 before any bytes are processed. It may be necessary to use unsigned values to prevent implementation dependant problems on systems with 16 bit integers.

Language Records

The Languages pointer field in the header points to the language records that specify which languages are supported by the SIS file. The Number of languages field in the header specifies the number of records. Each record consists of a 2 byte value from the following table:

LanguageCodeDescription
0x00000 Test
0x00011ENUK English
0x00022FRFrench
0x00033GEGerman
0x00044SPSpanish
0x00055ITItalian
0x00066SWSwedish
0x00077DADanish
0x00088NONorwegian
0x00099FIFinnish
0x000A10AMAmerican English
0x000B11SFSwiss French
0x000C12SGSwiss German
0x000D13POPortuguese
0x000E14TUTurkish
0x000F15ICIcelandic
0x001016RURussian
0x001117HUHungarian
0x001218DUDutch
0x001319BLBelgian Flemish
0x001420AUAustralian English
0x001521BGBelgian French
0x001622ASAustrian German
0x001723NZNew Zealand English
0x001824IFInternational French
0x001925CSCzech
0x001A26SKSlovak
0x001B27PLPolish
0x001C28SLSlovenian
0x001D29TCTaiwan Chinese
0x001E30HKHong Kong Chinese
0x001F31ZHPRC Chinese
0x002032JAJapanese
0x002133THThai
0x002234AFAfrikaans
0x002335SQAlbanian
0x002436AHAmharic
0x002537ARArabic
0x002638HYArmenian
0x002739TLTagalog
0x002840BEBelarussian
0x002941BNBengali
0x002A42BGBulgarian
0x002B43MYBurmese
0x002C44CACatalan
0x002D45HRCroatian
0x002E46CECanadian English
0x002F47IEInternational English
0x003048SFSouth African English
0x003149ETEstonian
0x003250FAFarsi
0x003351CFCanadian French
0x003452GDScots Gaelic
0x003553KAGeorgian
0x003654ELGreek
0x003755CGCyprus Greek
0x003856GUGujarati
0x003957HEHebrew
0x003A58HIHindi
0x003B59INIndonesian
0x003C60GAIrish
0x003D61SZSwiss Italian
0x003E62KNKannada
0x003F63KKKazakh
0x004064KMKhmer
0x004165KOKorean
0x004266LOLaothian
0x004367LVLatvian
0x004468LTLithuanian
0x004569MKMacedonian
0x004670MSMalay
0x004771MLMalayalam
0x004872MRMarathi
0x004973MOMoldavian
0x004A74MNMongolian
0x004B75NNNorwegian-Nynorsk
0x004C76BPBrazilian Portuguese
0x004D77PAPunjabi
0x004E78RORomanian
0x004F79SRSerbian
0x005080SISinhalese
0x005181SOSomali
0x005282OSInternational Spanish
0x005383LSLatin American Spanish
0x005484SHSwahili
0x005585FSFinland Swedish
0x005787TATamil
0x005888TETelugu
0x005989BOTibetan
0x005A90TITigrinya
0x005B91CTCyprus Turkish
0x005C92TKTurkmen
0x005D93UKUkrainian
0x005E94URUrdu
0x006096VIVietnamese
0x006197CYWelsh
0x006298ZUZulu

Note that SF is used for both Swiss French and South African English.

File Records

The Files pointer field in the header points to the file records that specify the details of the files to be installed. The Number of Files field in the header specifies the number of records. These are stored contiguously, in the reverse of the order required for installation. Each record starts with a 4 byte File record type field specifying the type of record that follows:

TypeDescription
0x00000000Simple file line
0x00000001Multiple language files line
0x00000002Options line
0x00000003If line
0x00000004ElseIf line
0x00000005Else line
0x00000006EndIf line

Simple File or Multiple Language Files Line Record

If the File record type field at the start of the record is 0x00000000 or 0x00000001 then the record specifies a single file to be installed. It is in the following format:

OffsetBytesDescription
0x0004File record type
0x0444File type
0x0884File details
0x0c124Source name length
0x10164Source name pointer
0x14204Destination name length
0x18244Destination name pointer
0x1c284nFile length(s)
0x1c
+ 4n
28
+ 4n
4nFile pointer(s)

The file records of EPOC release 6 format SIS files are extended:

OffsetBytesDescription
0x1c
+ 8n
28
+ 8n
4nOriginal file length(s)
0x1c
+ 12n
28
+ 12n
4MIME type length
0x20
+ 12n
32
+ 12n
4MIME type pointer

The File type consists of one of the following types:

File typeCodeDescription
0x000FFFILEStandard file (the default)
0x011FTFILETEXTText file to display during installation
0x022  SIS component file
0x033FRFILERUNFile to be run during installation and/or removal
0x044FNFILENULLFile does not yet exist, but will be created when the application is run
0x055FMFILEMIMEOpen file

The File details give extra information for the specified File type.

If the File type identifies a standard file (FF) then the file is installed on the target machine and File details is always 0x00000000.

If the File type identifies a text file (FT) then the file is not installed; it is just displayed during installation. The buttons to use are specified by the File details field:

File detailsCodeDescription
0x00000TCTEXTCONTINUEContinue (continue installation)
0x00011TSTEXTSKIPYes (continue installation), No (skip next file)
0x00022TATEXTABORTYes (continue installation), No (abort installation)
0x00033TETEXTEXITYes (continue installation), No (abort and undo installation)

If the File type identifies a SIS component file then the SIS component is installed, and File details is set to the UID of the application that the SIS file installs. Pointers within component SIS files are specified as offsets from the start of that file. Component SIS files are usually used for components that may be shared between multiple applications; they ensure that existing installations are not overwritten by earlier versions.

If the File type identifies a file to be run (FR) then it is installed on the target machine, and the File details field specifies when it should be run:

File detailsCodeDescription
0x00000RIRUNINSTALLRun during installation only
0x00011RRRUNREMOVERun during removal only
0x00022RBRUNBOTHRun during both installation and removal
0x0100256RERUNSENDENDClose when installation complete
0x0200512RW Wait until closed before continuing

If the File type field identifies a file that does not yet exist (FN) then the file will be created by the running application, and will be deleted when the application is removed. Note that the file will not be deleted when upgrading to a later version, ensuring that application preferences are not lost in an upgrade. The File details are always 0x00000000.

If the File type field identifies a file to open (FM) then the file will be opened during installation using the application associated with the MIME type, and the File details field specifies when it should be run:

File detailsCodeDescription
0x0100256OCClose when installation complete
0x0200512OWWait until closed before continuing

The Source name length and Source name pointer specify the length and offset of the source filename respectively. This is the path of the original file on the machine used to construct the SIS file; it does not affect the installation or removal process. The name is usually blank if the File type field identifies a file that does not yet exist (FN).

The Destination name length and Destination name pointer specify the length and offset of the target filename respectively. The drive letter may be specified as an exclamation mark ("!") to allow a choice of drive during installation. The name is usually blank if the File type field identifies a text file (FT).

The File length and File pointer specify the length and offset of the file contents respectively. The Original file length specifies the size of the file when uncompressed. If the File record type field specifies that there are multiple language versions, then the File length, File pointer and Original file length fields are individually repeated for each language version supported by the SIS file. These are specified in the same order as the language records.

Unless the NC option is set in the header, file data in EPOC release 6 format files is compressed using zlib's compress method.

The MIME type length and MIME type pointer fields specify the length and offset of the file's MIME type. If the file does not have a MIME type then the MIME type length field is set to 0x00000000 and the MIME type pointer field specifies the offset to the first byte after the end of the source and target filenames.

Options Line Record

If the File record type field at the start of the record is 0x00000002 then the record specifies selectable installation options. It has the following format:

OffsetBytesDescription
0x0004File record type
0x0444Number of options
0x0888mnOption strings
0x08
+ 8mn
8
+ 8mn
16Selected options

The Number of options field specifies the number of options defined by the Options strings field. Each option consists of a record in the following form:

OffsetBytesDescription
0x0004nOption string length(s)
4n4n4nOption string pointer(s)

The Option string length and Option string pointer specify the length and offset of the option description respectively. The Option string length and Option string pointer fields are individually repeated for each language version supported by the SIS file. These are specified in the same order as the language records.

The Selected options field is a bitmap with one bit for each of up to 128 options. Initially all bits are set, but when the SIS file is installed this is modified to record the selected options.

Options are displayed to the user at the stage of the installation at which they appear within the SIS file. They behave as global attributes (affecting embedded SIS files) and are tested within If and ElseIf line records. The attributes corresponding to option n is identified by 0x2000+n.

If or ElseIf Line Record

If the File record type field at the start of the record is 0x00000003 or 0x00000004 then the record specifies a conditional record in the following format:

OffsetBytesDescription
0x0004File record type
0x0444Size of conditional expression
0x088nConditional expression

The Size of conditional expression field specifies the size of the following Conditional expression.

The Conditional expression if recursively constructed from records that start with a Conditional type field:

TypeDescription
0x00000000(Attribute) = (Value)
0x00000001(Attribute) <> (Value)
0x00000002(Attribute) > (Value)
0x00000003(Attribute) < (Value)
0x00000004(Attribute) >= (Value)
0x00000005(Attribute) <= (Value)
0x00000006(Conditional expression) AND (Conditional expression)
0x00000007(Conditional expression) OR (Conditional expression)
0x00000008exists(Filename)
0x00000009devcap(Capability)
0x0000000aappcap(UID, Capability)
0x0000000bNOT(Conditional expression)
0x0000000cString
0x0000000dAttribute
0x0000000eNumber

If the Conditional type is 0x00000000 to 0x00000007 or 0x0000000a then it specifies a binary operator applied to two sub-expressions (each recursively constructed as for Conditional expression):

OffsetBytesDescription
0x0004Conditional type
0x044nLeft-hand side conditional sub-expression
0x04
+ n
4
+ n
mRight-hand side conditional sub-expression

The two sub-expressions for Conditional type 0x0000000a are always numbers (Conditional type 0x0000000e).

If the Conditional type is 0x00000008, 0x00000009 or 0x0000000b then it specifies a unary operator applied to a sub-expression (recursively constructed as for Conditional expression):

OffsetBytesDescription
0x0004Conditional type
0x044nConditional sub-expression

The sub-expression for Conditional type 0x00000008 is always a string (Conditional type 0x0000000c), and the sub-expression for Conditional type 0x00000009 is always a number (Conditional type 0x0000000e).

If the Conditional type is 0x0000000c then it specifies a string:

OffsetBytesDescription
0x0004Conditional type
0x0444String length
0x0884String pointer
If the Conditional type is 0x0000000d then it specifies an attribute:

OffsetBytesDescription
0x0004Conditional type
0x0444Attribute
0x0884Unused

The Attribute may be one of the following:

FlagCodeDescription
0x00000000Manufacturer0=Ericsson, 1=Motorola, 2=Nokia, 3=Panasonic, 4=Psion, 5=Intel, 6=Cogent, 7=Cirrus, etc
0x00000001ManufacturerHardwareRev0x0100 = 1.00 (manufacturer specific)
0x00000002ManufacturerSoftwareRev0x0100 = 1.00 (manufacturer specific)
0x00000003ManufacturerSoftwareBuild(manufacturer specific)
0x00000004Model 
0x00000005MachineUidDevice specific values for products as defined in epoc32/include/hal_data.h
0x00000006DeviceFamily0=Crystal, 1=Pearl, 2=Quartz
0x00000007DeviceFamilyRev0x0100 = 1.00
0x00000008CPU0=ARM, 1=MCORE, 2=x86
0x00000009CPUArch0x400=ARM4, 0x410=ARM4T, 0x500=ARM5, 0x300=M340
0x0000000aCPUABI0=ARM4, 1=ARMI, 2=THUMB, 3=MCORE, 4=MSVC
0x0000000bCPUSpeedCPU clock speed / 1024, e.g. 36864=36MHz
0x0000000eSystemTickPeriodTick period in microseconds
 SystemSpeedApproximate speed relative to Psion Series 5 = 100
0x0000000fMemoryRAMTotal RAM size in bytes
0x00000010MemoryRAMFreeFree RAM size in bytes
0x00000011MemoryROMTotal ROM size
0x00000012MemoryPageSizeSize of memory management unit pages
0x00000015PowerBackup0=none, 1=supported
0x00000018Keyboard0=none, 1=keypad, 2=full, 3=both
0x00000019KeyboardDeviceKeysNumber of device specific keys
0x0000001aKeyboardAppKeysNumber of application keys
0x0000001bKeyboardClick0=none, 1=supported
0x0000001eKeyboardClickVolumeMax 
0x0000001fDisplayXPixelsScreen width in pixels
0x00000020DisplayYPixelsScreen height in pixels
0x00000021DisplayXTwipsScreen width in twips (1/1440 inch)
0x00000022DisplayYTwipsScreen height in twips (1/1440 inch)
0x00000023DisplayColors2, 4, 16, 256, 65536, etc
0x00000026DisplayContrastMax 
0x00000027Backlight0=none, 1=supported
0x00000029Pen0=none, 1=supported
0x0000002aPenXPen horizontal resolution
0x0000002bPenYPen vertical resolution
0x0000002cPenDisplayOn0=no 1=yes
0x0000002dPenClick0=none, 1=supported
0x00000030PenClickVolumeMax 
0x00000031Mouse0=none, 1=supported
0x00000032MouseXMouse horizontal resolution
0x00000033MouseYMouse vertical resolution
0x00000037MouseButtonsNumber of mouse buttons
0x0000003aCaseSwitch0=none, 1=supported
0x0000003dLEDsNumber of LEDs
0x0000003fIntegratedPhone0=none, 1=supported
0x00000041DisplayBrightnessMax 
0x00000042KeyboardBacklightState 
0x00000043AccessoryPower 
0x00000059NumHalAttributesNumber of supported HAL attributes
0x00001000LanguageMachine language
0x00001001RemoteInstall0=Symbian OS based install, 1=installation via a PC
0x00002000
+ n
Option<n>0=option not selected, 1=option selected

If the Conditional type is 0x0000000e then it specifies a number:

OffsetBytesDescription
0x0004Conditional type
0x0444Number
0x0884Unused

Else or EndIf Line Record

If the File record type field at the start of the record is 0x00000005 or 0x00000006 then the record consists of just the type field:

OffsetBytesDescription
0x0004File record type

Requisite Records

The Requisites pointer field in the header points to the requisites records that specify the files that are required by the component being installed. The Number of requisites field in the header specifies the number of records. These are stored contiguously in the following format:

OffsetBytesDescription
0x0004UID
0x0442Major version
0x0662Minor version
0x0884Variant
0x0c124nRequisite name length(s)
0x0c
+ 4n
12
+ 4n
4nRequisite name pointer(s)

The UID field specifies the UID of the component that is required, i.e. the first word of its residual SIS file.

The Major version and Minor version fields specify the minimum version number of the component required. The Minor version number is padded to two digits with leading zeros for display. This is not checked by the control panel Add/remove program.

The Variant field specifies the variant of the component that is required. This is usually set to 0x00000000, and is not checked by the control panel Add/remove program.

The Requisite name length and Requisite name pointer specify the length and offset of the requite name respectively. The Requisite name length and Requisite name pointer fields are individually repeated for each language version supported by the SIS file. These are specified in the same order as the language records.

The requisite name is only used for display during installation; it does not need to match for the requisite to be satisfied.

Component Name Record

The Component name pointer field in the header points to the component name record that specifies the name of the component to be installed. This is used both during installation and for the list of installed applications in the control panel Add/remove program. The record is in the following format:

OffsetBytesDescription
0x0004nName length(s)
4n4n4nName pointer(s)

The Name length and Name pointer specify the length and offset of the component name respectively. The Name length and Name pointer fields are individually repeated for each language version supported by the SIS file. These are specified in the same order as the language records.

Capabilities Record

The Capabilities pointer field in the header points to the capabilities record. The record is in the following format:

OffsetBytesDescription
0x0004nKey
4n4n4nValue

 

Certificates Record

The Certificates pointer field in the header points to the certificates records. The record is in the following format:

OffsetBytesDescription
0x0002Year
0x0222Month
0x0442Day
0x0662Hour
0x0882Minute
0x0A102Second
0x0C124Number of certificates

The Year, Month, Day, Hour, Minute and Second fields form a timestamp.

The Number of certificates field specifies the number of certificates.

Resource Data

The remainder of the SIS file consists of the data referenced from the other sections. This is stored uncompressed and unpadded, usually in the following order:

Section
String Block, containing:
  • File Names
  • Requisite Name
  • Component Name
Code Block
Signature Block

If, for some reason, the resource data is arranged with the code block (containing the file data) before the component name, then the residual SIS file will be larger than necessary.

Installation

Installation of an SIS file requires several steps to be performed. These are described in the following sections.

These operations need to be repeated for any embedded component SIS files.

Select Language

SIS files may support more than one language, as indicated by the Number of languages field in the header and the language records. The control panel Add/remove program attempts to use the current language of the machine, but EPOC Connect prompts the user to choose from the available options.

Check Requisites

The requisite records specify a list of other components that need to be installed. The residual SIS files on the target machine should be searched to verify that a suitable version of the required component has been installed.

Check Previous Version

The residual SIS files on the target machine are used to check for any previous versions of the application being installed. Any previous installation needs to be removed before installing the new version.

If the previous version is older than the version being installed then it is replaced without warning. However, if the previous version is newer then the behaviour depends on the installation program; the control panel Add/remove program requires the user to first uninstall the more recent version, but EPOC Connect displays a confirmation prompt to allow the existing application to be removed and replaced.

Copy Files

The file records should be processed in the reverse of the order that they are stored in the SIS file. Text files should be displayed and component SIS files installed as they are encountered.

SIS files sometimes allow the user to select the installation drive. This is indicated by the destination file names having an exclamation mark ("!") specified as the drive letter. In this case the user should be prompted to select from the available drives.

Directories should be created automatically to accommodate files being copied.

Residual SIS File

A residual SIS file is created in the C:/System/Install/ directory on the target machine. This allows the control panel to display a list of installed programs, and provides the dependency information required for removing the component or installing other applications.

The main modification is that the file is truncated after the file name and component name strings. This usually means that the file data is omitted, but this relies upon the SIS file contents being in a sensible order.

Finally, three fields in the header are modified with the settings used for the installation. The Installation language field is set to the language selected for the installation, the Installation files field is set to the number of files installed, and the Installation drive field is set to the drive letter where the files were installed.

Removal

Removing an application consists of deleting all the files listed within the residual SIS file. This includes any component SIS files and the residual SIS file itself.

Before a component is removed, all other residual SIS files need to be checked to verify that it is not required by another application. When uninstallation of a component involves the removal of another component's requisite files, the user is warned that continuing may prevent other programs from working.

If the application is being removed to allow a newer version to be installed then files with a File type field indicating a file created by the application (FN) should not be removed.

Partial Installation

If an installation or removal is aborted, the Installation files field is set to the number of files that are left installed. The control panel Add/remove program marks any such installations as "Partial" in the list of installed applications, and offers options to either resume the installation or to uninstall the application.

 

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