Abstract: Systems, methods, and computer program products for embedding a foreign data block in a host data file. In general, in one aspect, the computer-implemented method includes receiving a host data file, the host data file having a host data file format, receiving a packet to be embedded into the host data file, the packet including a foreign data block and further including a header and a trailer that delimit the foreign data block, the header including an identifier designed to be distinguishable from all other data in the host data file, a byte pattern that indicates a presence of the header, and a character encoding format of the foreign data block, the byte pattern selected based on the character encoding format of the foreign data block, and embedding the packet in the host data file.

Abstract: Methods and apparatus, including computer programs, implementing a technique for creating and using marked foreign data blocks. In general, in one aspect, the technique includes receiving a host data file and a foreign data block. The host data file has a host data file format that is a native file format for a host application. The foreign data block is not native to the host data file format. The technique includes determining characteristics of the foreign data block and generating information describing the characteristics of the foreign data block, including information marking the beginning and end of the foreign data block and further including an identifier designed to be distinguishable from all other data in the host data file. The technique includes embedding the information and the foreign data block as a foreign data block packet in the host data file.

Abstract: Methods and apparatus, including computer programs, implementing a technique for creating and using marked foreign data blocks. In general, in one aspect, the technique includes receiving a host data file and a foreign data block. The host data file has a host data file format that is a native file format for a host application. The foreign data block is not native to the host data file format. The technique includes determining characteristics of the foreign data block and generating information describing the characteristics of the foreign data block, including information marking the beginning and end of the foreign data block and further including an identifier designed to be distinguishable from all other data in the host data file. The technique includes embedding the information and the foreign data block as a foreign data block packet in the host data file.

Abstract: The invention provides a method and apparatus for switching between execution of a plurality of object code types having different conventions for invoking program procedures and performing stack manipulations. The invention may also be used to switch between different calling conventions within a single object code type. Briefly according to the invention, a computer system comprises a routine descriptor, a stack switch frame, a mode switching mechanism for switching from a first processor, code or calling convention type to a second processor, code or calling convention type and means for executing instructions in various code types. A routine descriptor describes a program or code segment and its code type and calling conventions. A routine descriptor contains, among other information, a “mixed mode” field which is set to a specific, predetermined value such as a value indicating an instruction which is not legal in the runtime environment of a first processor, code or calling convention type.

Abstract: The invention provides a method and apparatus for switching between execution of a plurality of object code types having different conventions for invoking program procedures and performing stack manipulations. The invention may also be used to switch between different calling conventions within a single object code type. Briefly according to the invention, a computer system comprises a routine descriptor, a stack switch frame, a mode switching mechanism for switching from a first processor, code or calling convention type to a second processor, code or calling convention type and means for executing instructions in various code type codes. A routine descriptor describes a program or code segment and its code type and calling conventions. A routine descriptor contains, among other information, a "mixed mode" field which is set to a specific, predetermined value such as a value indicating an instruction which is not legal in the runtime environment of a first processor, code or calling convention type.