# Patent

## Title
Methods and apparatus to support mixed-mode execution within a single instruction set architecture process of a virtual machine

## Abstract

Methods and apparatus to support the execution of a managed application that is linked to a native library or application are disclosed. The disclosed methods and apparatus support a virtual machine that is associated with the same ISA as the executing platform, while the ISA of the native library or application is of a different ISA. The disclosed methods and apparatus also support the execution of a managed application that is linked with several native libraries or applications that are associated with several different ISAs respectively.

## Background
TECHNICAL FIELD
The present disclosure relates generally to processor systems and, more particularly, to methods and apparatus to support mixed mode execution within a single instruction set architecture.
BACKGROUND
The need for increased software application portability (i.e., the ability to execute a given software application on a variety of platforms having different hardware, operating systems, etc.), as well as the need to reduce time to market for independent software vendors (ISVs), have resulted in increased development and usage of managed runtime environments and virtual machines.
Virtual machines (VMs) are typically implemented using a dynamic programming language such as, for example, Java and C#. A software engine (e.g., a Java Virtual Machine (JVM) and Microsoft .NET Common Language Runtime (CLR), etc.), which is commonly referred to as a runtime environment, executes the dynamic program language instructions of the managed application. The VM interfaces dynamic program language instructions (e.g., a Java program or source code) to be executed and to a target platform (i.e., the hardware and operating system(s) of the computer executing the dynamic program) so that the dynamic program can be executed in a platform independent manner.
Dynamic program language instructions (e.g., Java instructions) are not statically compiled and linked directly into native or machine code for execution by the target platform (i.e., the operating system and hardware of the target processing system or platform). Native code or, machine code, is code that is compiled down to methods or instructions that are specific to the operating system and/or processor. In contrast, dynamic program language instructions are statically compiled into an intermediate language (e.g., bytecodes), which may interpreted or subsequently compiled by a just-in-time (JIT) compiler into native or machine code that can be executed by the target processing system or platform. Typically, the JIT compiler is provided by the VM that is hosted by the operating system of a target processing platform such as, for example, a computer system. Thus, the VM and, in particular, the JIT compiler, translates platform independent program instructions (e.g., Java bytecodes, Common Intermediate Language (CIL), etc.) into native code (i.e., machine code that can be executed by an underlying target processing system or platform).
VMs typically include interfaces (e.g., Java Native Interface (JNI)) to native libraries, which may be applications and/or libraries of procedures written in native programming languages (e.g., C, C++, assembly, etc.) that operate on or with the target platform. Interfacing with native libraries enables a managed application developer to call or utilize libraries that are already written, interface the managed application with hardware drivers written in native languages, and perform procedures that are not supported by the managed programming language.
A drawback to using native libraries from inside a VM is that the native libraries, unlike managed applications, are not platform-independent, unlike managed applications. Software applications written in native languages are linked directly into the native code of the platform on which they are compiled. In other words, the native libraries are not translated into the native instructions of the platform on which they are executing. Thus, the native libraries must be compiled for each ISA platform on which they are running. For example, a native library written in C and compiled on an Intel Pentium 4 processor (IA-32 instruction set architecture (ISA)) cannot be executed on an Intel Itanium processor family (IPF) ISA. Therefore, if a developer would like to move a managed application or VM from one processor platform to another, they must rewrite and/or recompile any native libraries that are required.
To enable the execution of managed applications that are linked to native libraries that are associated with ISAs different from the ISA of the operating platform, developers have created several strategies. One method utilizes one VM for each ISA with which native libraries are associated. For example, to execute a managed application linked to a 32-bit native library a 32-bit VM is used and to execute a managed application linked to a 64-bit native library a 64-bit VM is used. In such an arrangement, the VM translates the managed application bytecode to the ISA of the emulation layer (which is different than the current platform's ISA). Subsequently, the emulation layer translates the managed application bytecode to the ISA of the current platform. This double translation results in a decrease in performance when executing managed applications and is, thus, undesirable. This approach requires increased complexity due to the multiple required VMs and does not allow managed applications that link to two or more native libraries that are associated with different ISAs to be executed.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an example architecture that may be used to implement the disclosed methods and apparatus.
FIG. 2 is a block diagram of an example system for implementing the translator of FIG. 1.
FIG. 3 is a flow diagram of an example process for executing a managed application that is linked to a native library.
FIG. 4 is a flow diagram showing further detail of one example incompatible library loading process of FIG. 3.
FIG. 5 is a flow diagram showing further detail of one example locate incompatible procedure call process of FIG. 3.
FIG. 6 is a flow diagram showing further detail of one example invoke procedure process of FIG. 3.
FIG. 7 is a block diagram of one example implementation of the disclosed systems and methods using a java virtual machine.
FIG. 8 is a block diagram of an example process of loading a library according to the implementation of FIG. 6.
FIG. 9 is a block diagram of an example process for looking up a method in a native table according to the implementation of FIG. 6.
FIG. 10 is a block diagram of an example system for handling a call to a procedure in a native library.
FIG. 11 is a block diagram of an example process for invoking a procedure in a native library according to the implementation of FIG. 6.
FIG. 12 is an example processor system that may be used to implement the systems and methods disclosed herein.



DETAILED DESCRIPTION
FIG. 1 is a block diagram of an example architecture 100 that may be used for implementing the proposed methods and apparatus. The example architecture 100 includes an operating system 102; a CPU 102; a managed application 106 that is executed within a VM 108, which includes one or more interfaces 109, one or more handle table(s) 110; a translator 112; and one or more native libraries 114. The example architecture may be implemented as a part of a computer system that is shown in FIG. 11 and will be described in detail later.
The CPU 102 has an associated ISA that defines the design of the CPU 102, such as the configuration of registers and the machine language that is implemented on the CPU 102. The CPU 102 is capable of executing machine language instructions that may be a part of a computer program. Example CPU ISAs are the Intel Itanium Architecture of the IPF and the Extended Memory Technology (EM64T) architecture. These are examples of 64-bit architectures. Another example CPU ISA is the 32-bit IA-32 architecture.
The operating system (OS) 104 is capable of controlling and allocating access to the hardware and software components in a computer system, such as the CPU 102. The OS 104 may manage the execution of the software applications by scheduling time on the processor, allowing access to memory components, and setting priority with other software applications. Example OSs 104 include Microsoft Windows XP, RedHat Linux, and BSD Unix.
The managed application 106 is a software application that may be written using a platform independent language such as, for example, Java or C#. However, any other platform independent computer language or instructions could be used instead. The managed application 106 may be stored on a memory within the example architecture 100 or may alternatively be stored on a remote architecture. The VM 108 statically compiles the managed application 106 to generate compiled code. The compiled code is intermediate language code or instructions (e.g., bytecodes in the case where the managed application 106 is written in Java) that is stored in a binary format in a memory (not shown). The VM 108 generates compiled code that is compatible with the OS 104 and the CPU 102 so that portions of the code may be executed thereon. In other words, the compiled code is compatible with the ISA of the example architecture. The VM 108 also includes one or more interface(s) 109 that allow the VM 108 to initiate communication with the translator 112, which will be further described in detail herein. Example VMs 104 include the Java Virtual Machine (JVM) and the Microsoft .NET Common Language Interpreter (CLI). Of course, any VM could be used to implement the VM 108.
The VM 108 may further include one or more handle table(s) 110. The handle table(s) 110 are capable of storing the memory locations of libraries and procedures. In particular, the handle table(s) 110 may store the mapping of the original location of a library or procedure to a translated version of that library or procedure. The handle table(s) 110 may be implemented in the memory allocated to the VM 108.
The native libraries 114 may be any libraries that are compiled into native code (machine language). The native libraries 114 may be written in a platform-dependent programming language such as C. The native library 114 may implement functions that are not available in the programming language of the managed application 106. The native libraries 114 are compiled to native code and therefore, cannot be executed on an architecture that does not implement the associated native code without translation. For example, a native library that is compiled to IA-32 native code cannot be executed on a 64-bit IPF platform.
The translator 112 is a software application that may translate machine language instructions of a compiled native library from one ISA to a different ISA. Specifically, the translator 112 is capable of translating the native libraries 114 to the ISA of the current platform. For example, the translator 112 may translate the IA-32 native library to 64-bit IPF machine language instructions. Further, the translator 112 is capable of mapping the location of procedure calls in the original machine language to the location of the translated procedure calls. The translator 112 may provide the mapping to the VM 108 so that it may store the location in the handle table(s) 110. The translator 112 may be implemented by way of a discrete software driver, a component of the operating system, or an embedded function of the CPU 102. An example of a translator 112 is the IA-32 Execution Layer (EL). The IA-32 EL is a software package from Intel for running IA-32 applications on IPF processors.
In general, the VM 108 translates the managed application 106 to machine code that is executed on the CPU 102 in conjunction with the operating system 104. When a reference to the native library 114 is reached during the translation, the VM 108 directs the reference to the interfaces 109. The interfaces 109 further direct the reference to the translator 112. The translator 112 will load the library, locate a procedure, or translate a procedure depending on the type of the reference (e.g., library loading, procedure call, etc.) Throughout the execution process, the VM 108 receives handle information regarding the native library 114 and the procedures contained therein from the translator 112. The VM 108 stores the handles in the handle table 110.
FIG. 2 is a block diagram of one example implementation of the translator 112. The translator 112 may include an interface 202 and a dynamic binary translator 208. The interface 202 defines an application program interface (API) that enables communication between the VM 108 and the dynamic binary translator 208. In this example, the interface 202 includes a loader 204 and a stub 206. The interface 202 may replace a similar interface that is included with the VM 108 so that library loading and procedure calls may be redirected to the translator 112.
The loader 204 provides an interface for the VM 108 to call for the loading of one of the native libraries 114. The loader 204 is capable of redirecting a call to load one of the native libraries 114 to the dynamic binary translator 208. The loader 204 may further be capable of returning information about the one of the native libraries 114 to the VM 108.
The stub 206 provides an interface for the VM 108 to call one of the procedures in the one of the native libraries 114. The stub 206 is capable of redirecting a call to a procedure in the one of the native libraries 114 to the dynamic binary translator 208 for translation. The stub 206 may further be capable of passing returned values from the execution of the procedure to the VM 108.
The dynamic binary translator 208 is capable of translating native code from one ISA to another. The dynamic binary translator may additionally be capable of locating a procedure in a translated native code and returning the location of that procedure. One of ordinary skill in the art will recognize that a dynamic binary translator may be capable of translating native code from several ISAs or additionally that multiple dynamic binary translators may be provided in a system to support the execution of native libraries associated with several ISAs.
FIG. 3 is a flowchart of an example process supporting the execution of a managed application 106 that includes calls to native libraries 114 that are of a different ISA than the ISA of the architecture 100. The method of FIG. 3 may take place during the execution of the managed application 106 in the VM 108. The example of FIG. 3 assumes that the managed application 106 includes a call to load one of the native libraries 114 followed by a call to one of the procedures in the one of the native libraries 114.
When the VM 108 attempts to load one of the native libraries 114 that is not supported by the architecture 100, the library will fail to load. The translator 112 can locate and load the one of the native libraries 114 with the dynamic binary translator 208 (block 302).
When the VM 108 attempts to locate a procedure in the one of the native libraries 114, the VM 108 will initially fail to locate the procedure because the call is to a procedure in a library that is not supported by the architecture 100 (block 302). The translator 112 locates the procedure in the one of the native libraries 114 that was loaded in block 302 and returns the location of the procedure (block 304). After the one of the native libraries 114 has been loaded and the procedure call has been located, the VM 108 can invoke the procedure using the translator 112 (block 306).
FIG. 4 is a flowchart of one example method for implementing the loading of an incompatible library of block 302. After the VM 108 fails to load the one of the native libraries 114, the VM 108 checks to determine if the one of the native libraries 114 exists (block 402). If the one of the native libraries 114 does not exist, an error is returned to indicate that the one of the native libraries 114 is missing (block 404). If the one of the native libraries 114 does exist, it is assumed that it could not be loaded because it is not supported by the architecture 100. The VM 108 then calls the loader 204 of the interface 202 to attempt to load the one of the native libraries 114 (block 406). The loader 204 directs the request to load the one of the native libraries 114 to the dynamic binary translator 208.
The dynamic binary translator 208 then loads the one of the native libraries 114 (block 408). The dynamic binary translator 208 passes the handle of the loaded one of the native libraries 114 to the VM 108 through the loader 204 (block 410). The VM 108 may then store the handle of the loaded one of the native libraries 114 in the one or more handle table(s) 110 (block 412). The VM then proceeds with loading and execution of the managed application 106.
FIG. 5 is a flowchart of one example method for implementing the locate incompatible procedure call of block 304. The VM 108 will attempt to locate the procedure in the native library 114 (block 502). If the address of the procedure is found, the locate procedure method is complete. If the address of the procedure cannot be found, the procedure is assumed to be associated with an ISA that is different than the ISA of the current platform (block 503). The VM 108 then calls the loader 204 of the interface 202 to attempt to locate the procedure in the one of the native libraries 114 (block 504). The VM 108 passes the handle of the translated one of the native libraries 114 to the loader 204. The loader 204 locates the procedure in the translated one of the native libraries 114 (block 506). The loader 204 returns the handle of the procedure in the translated one of the native libraries 114 to the VM 108. The VM 108 then stores the handle in the handle table(s) 110.
FIG. 6 is a flowchart of an example method for implementing the invoke procedure of block 306. The VM 108 first locates the handle for the procedure in the handle table(s) 110 (block 602). The VM 108 then calls the stub 206 in the interface 202 and passes the handle for the procedure and any other parameters that are associated with the procedure call (block 604). The stub prepares the VM for executing the procedure (e.g., generates a stack frame, context, etc.) and redirects the call to the dynamic binary translator 208. The dynamic binary translator 208 translates the procedure to the ISA of the architecture 100 (block 606). The dynamic binary translator 208 then executes the translated code on the CPU 102 via the operating system 104 (block 608). The procedure may return values, which are then passed back to the VM 108 via the stub 206. After the procedure finishes executing control is returned to the VM 108 and the next line of the managed application 106 may be executed.
Turning now to FIG. 7, another example implementation of an architecture for executing a managed application that is linked with a native library that is not supported by the architecture is provided. The architecture 700 of FIG. 7 is an implementation for the Java programming language. The architecture 700 generally includes a 64-bit JVM 702, an IA-32 EL interface 704, 32-bit native library 706, and an IA-32 EL translator 708. These components may be substantially similar to the VM 108, the interface 202 of the translator 112, the one or more native libraries 114, and the dynamic binary translator 208 of the translator 112, respectively. FIG. 7 does not show a block for the managed application, operating system, and CPU that are a part of the overall architecture 700.
The 64-bit JVM 702 includes a VM Startup method 710 for startup and initialization of the 64-bit JVM. The VM Startup method 710 makes calls to initialization functions 722 of the IA-32 EL interface 704 to startup and initialize the IA-32 EL. The 64-bit JVM 702 further includes one or more library/symbol handle table(s) 712. The library/symbol handle table(s) 712 may be substantially similar to the handle table(s) 110 of FIG. 1. The 64-bit JVM 702 may make calls to the Loader32 method 724 to load libraries and locate procedures in loaded libraries. As shown in the figure, the procedure calls are java2bt_dlopen( ) and java2bt_dlsym( ) respectively. Loader32 returns the handles of the libraries and procedures to the Library/Symbol Handle Table(s) 712.
FIG. 7 includes one or more calls to a procedure in a native library shown as JNICall 714. If the procedure that is called by JNICall 714 is in a native library that is not supported by the platform, the JVM 702 must translate the call. The JVM 702 redirects the JNICall 714 from the actual procedure call to a call to the Stub32 method 726 using java2bt_stub32( ). The Stub32 method 726 retrieves the handle for the procedure from the library/symbol handle table(s) 712. The Stub32 method 726 then calls the JNI method 734 of the 32-bit native library 706 using the handle of the procedure. The JNI method 734 is translated and executed via the IA-32 EL translator 708. Any values returned from the JNI method 734 may be passed back to the JNICall 714 in the 64-bit JVM 702.
To enable the JNI method 734 to reference objects in the 64-bit JVM, the 64-bit JVM 702 includes JNIEnv64 716 and the IA-32 EL interface 704 includes the JNIEnv32 732. The JNIEnv32 732 is capable of intercepting calls to objects in the 64-bit JVM 702 by the JNI method 734 and translating the calls to reference the 64-bit objects. The JNIEnv32 732 then passes the calls to the JNIEnv64 716 via Up-Call. The JNIEnv32 732 is capable of handling object marshalling to convert 32-bit calls into 64-bit calls. One of ordinary skill in the art will recognize that values and calls may be passed back to the JNI method 734 via the JNIEnv64 716 and the JNIEnv32 732.
To handle any exceptions or errors that may occur, the 64-bit JVM 702 includes Signal Handler 718 and the IA-32EL includes Signal Handler Module 728. The Signal handler 718 and Signal Handler Module 728 can determine if an exception has occurred in the java code related to a managed application or in the code of a native library such as 32-bit native library 706 and handle the exception accordingly via the procedure ExceptionHandler( ).
The 64-bit JVM 702 includes a thread information block (TIB) 720 and the IA-32 EL interface 704 includes a thread local storage (TLS) 730. The TIB 720 and the TLS 730 support the emulation of threads and multi-threading for the managed application and the native library 706 respectively. Initializing a thread creates and initializes a segment of memory for execution a some set of instructions (e.g., instructions of a managed application). Using the interface method java2bt_init( ) the TIB 720 can signal to the TLS 730 to initialize a thread and process information can be transferred between the JVM 702 and the IA-32 EL interface 704.
FIG. 8 is a block diagram of a method for loading a native library in the architecture 700. The diagram includes managed application 802, which includes instruction 804 for loading the native library 810. When a JVM 806 reaches the instruction 804 the JVM 806 calls java2bt_dlopen( ), which attempts to load the native library 810 via a dynamic translator 808. The dynamic translator 808 may be substantially similar to the IA-32 EL translator 708 shown in FIG. 7. The dynamic translator 808 may then pass a handle for the library 812 to the JVM 806 for storage in the handle table 814.
FIG. 9 is a block diagram of a method for locating a procedure in native library 810 in the architecture 700. When the JVM 806 reaches an instruction 902 for calling a procedure in native library 810 during execution of managed application 802, the JVM 806 calls java2bt_dlsym( ). This method directs the call to the dynamic translator 808 which locates the handle of the native library 810 that includes the procedure in the handle table 814 and then locates the procedure in the native library 810. The dynamic translator 808, then returns the handle of the procedure to the JVM 806 for storage in the handle table 814.
FIG. 10 is a block diagram of an example system 1000 for handling a call to a procedure in the native library. The example system 1000 includes an IPF MRTE 1002, a data marshalling table 1004, a translator 1006, and a native library 1008.
The IPF MRTE 1002 is an IPF implementation of the JVM. The IPF MRTE may include a JNI 1010, a JNI Call procedure 1012, and JNI Up-Call procedures 1014. The JNI 1010 is a set of procedures for enabling managed applications that are executed inside of the IPF MRTE 1002 to access native libraries, such as native library 1008. The JNI 1010 includes the JNI Call procedure 1012 to enable a managed application to make a call to a procedure in the native library 1008. The JNI 1010 includes the JNI Up-Call 1014 procedures to enable the native library to pass data to and make calls to procedures in the managed application.
The translator 1006 is implemented by a IA-32 EL in the example system 1000. The translator 1006 translates procedures in the native library 1008 to the ISA of the platform. In the example system 1000, the translator 1006 translates the native library procedures from IA-32 ISA to 64-bit IPF ISA. The translator 1006 includes a JNI Call Stub 1016 that receives calls from the JNI Call 1012. The JNI Call Stub 1016 receives the procedure call and directs the call to a copy of the procedure that has been translated to the 64-bit IPF ISA by the translator 1006. The JNI Up-Call Stub 1018 enables procedures in the native library 1008 to make calls or pass data to the managed application via the JNI 1010 and the JNI Up-Call procedures 1014.
The procedure calls and data passed between the JVM 1002 and the translator 1006 must be transformed because the JVM 1002 and the translator 1006 are associated with different ISA platforms. The translation of procedure calls and data is handled by the JNI Call Stub 1016. When the JNI Call Stub 1016 receives a pointer or reference associated with the location of the data in the IPF ISA space, the pointer or reference is written to the data marshalling table 1004. The address of the pointer or reference in the data marshalling table 1004 is then passed to the call in the native library 1008. When the procedure that is called from the native library 1008 attempts to access the data using the JNI Up-Call Stub 1018 the original pointer or reference is retrieved from the data marshalling table 1004 using the address that was passed to the call in the native library 1008. The request is then sent to the JNI Up-Call 1014 using the retrieved original pointer or reference. One of ordinary skill in the art will recognize that the same procedure happens in the opposite direction when a procedure in the native library 1008 calls a procedure in the managed application and passes a pointer or reference to some data.
The data marshalling table 1004 may capable of transforming requests for many different combinations of ISA platform. For example, the data marshalling table 1004 may translate references from 64-bit IPF to SPARC-64 and back, from 64-bit IPF to IA-32 and back, or any other combination.
While FIG. 10 shows a specific implementation of a system for handling calls to procedures, one of ordinary skill in the art will recognize that FIG. 10 is merely an example implementation and that any suitable programming language, platform, and/or translation architecture may be utilized.
FIG. 11 is a block diagram of a process for invoking a procedure in the native library 810 in the architecture 700. FIG. 11 includes a portion of a Java application 1102, a symbol lookup table 1104, a portion of a JVM code generator 1106, a portion of generated code 1108, a dynamic translator 1110, a translated version of a native code procedure 1112. The portion of the JVM code generator 1106 executes on the portion of the Java application 1102. The JVM code generator 1106 includes the symbol lookup table 1104 that contains handles to native libraries and procedures. The JVM code generator 1106 generates the portion of generated code 1108 from the portion of the Java application 1102 replacing calls to native code that is not supported by the platform with calls to a stub function java2bt_stub32( ) 1114. The stub function java2bt_stub32( ) 1114 directs the procedure call to the translated version of the native code procedure 1112 generated by the dynamic binary translator 1110. The translated version of the native cod procedure 1112 is then executed by the platform.
In general, the portion of the Java application 1102 includes an instruction that references the native code procedure 1112. When executing the portion of the Java application 1102 generates the machine code of the generated code 1108 using the JVM code generator 1106. The JVM code generator 1106 replaces the reference to the native code 1112 with a call to the stub function java2bt_stub32( ) 1114. Then generated code is then executed. Once the call to the stub function java2bt_stub32( ) is reached during execution, the stub function java2bt_stub32( ) directs the reference to the native code procedure 1112 to the dynamic translator 1110. The dynamic translator 1110 translates the native code procedure 1112 to machine code that is compatible with the platform. The translated native code procedure is then executed.
Turning now to FIG. 12, an example processor system 1200 includes a processor 1202, having associated system memory 1204. The processor 1202 may be substantially similar to the CPU 122 of FIG. 1. The system memory 1204 may include one or more of a random access memory (RAM) 1206, a read only memory (ROM) 1208 and a flash memory 1210. The ROM 1208 and the flash memory 1210 of the illustrated example may respectively include boot blocks 1209 and 1212.
The processor 1202, in the example of FIG. 12, is coupled to an interface, such as a bus 1214 to which other peripherals or devices are interfaced. In the illustrated example, the peripherals interfaced to the bus 1214 include an input device 1216, a disk controller 1220 communicatively coupled to a mass storage device 1222 (i.e., hard disk drive) having a host protected area 1224, and a removable storage device drive 1226. The removable storage device drive 1226 may include associated removable storage media 1228, such as magnetic or optical media.
The example processor system 1200 of FIG. 12 also includes an adapter card 1230, which is a peripheral coupled to the bus 1214 and further coupled to a display device 1232.
The example processor system 1200 may be, for example, a conventional desktop personal computer, a notebook computer, a workstation or any other computing device. The processor 1202 may be any type of processing unit, such as a microprocessor from the Intel® Pentium® family of microprocessors, the Intel® Itanium® family of microprocessors, and/or the Intel XScale® family of processors.
The memories 1206, 1208, and 1210, which form some or all of the system memory 1204, may be any suitable memory devices and may be sized to fit the storage demands of the system 1200. The ROM 1208, the flash memory 1210, and the mass storage device 1222 are non-volatile memories. Additionally, the mass storage device 1222 may be, for example, any magnetic or optical media that is readable by the processor 1202.
The input device 1216 may be implemented by a keyboard, a mouse, a touch screen, a track pad or any other device that enables a user to provide information to the processor 1202.
The display device 1232 may be, for example, a liquid crystal display (LCD) monitor, a cathode ray tube (CRT) monitor, or any other suitable device that acts as an interface between the processor 1202 and a user via the adapter card 1230. The adapter card 1230 is any device used to interface the display device 1232 to the bus 1214. Such cards are presently commercially available from, for example, Creative Labs and other like vendors.
The removable storage device drive 1226 may be, for example, an optical drive, such as a compact disk-recordable (CD-R) drive, a compact disk-rewritable (CD-RW) drive, a digital versatile disk (DVD) drive or any other optical drive. It may alternatively be, for example, a magnetic media drive. The removable storage media 1228 is complimentary to the removable storage device drive 1226, inasmuch as the media 1228 is selected to operate with the drive 1226. For example, if the removable storage device drive 1226 is an optical drive, the removable storage media 1228 may be a CD-R disk, a CD-RW disk, a DVD disk or any other suitable optical disk. On the other hand, if the removable storage device drive 1226 is a magnetic media device, the removable storage media 1228 may be, for example, a diskette, or any other suitable magnetic storage media.
The example processor system 1200 also includes a network adapter 1236 (i.e., a processor peripheral), such as, for example, an Ethernet card or any other card that may be wired or wireless. The network adapter 1236 provides network connectivity between the processor 1202 and a network 1240, which may be a local area network (LAN), a wide area network (WAN), the Internet, or any other suitable network. As shown in FIG. 12, further processor systems 1244 may be coupled to the network 1240, thereby providing for information exchange between the processor 1202 and the processors of the processor systems 1244.
Of course, one of ordinary skill in the art will recognize that the order, size, and proportions of the memory illustrated in the example systems may vary. For example, the user/hardware variable space may be sufficiently larger than the main firmware instructions space. Additionally, although the forgoing discloses example systems including, among other components, software or firmware executed on hardware, it should be noted that such systems are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of these hardware and software components could be embodied exclusively in hardware, exclusively in software, exclusively in firmware or in some combination of hardware, firmware and/or software. Accordingly, while the following describes example systems, persons of ordinary skill in the art will readily appreciate that the examples are not the only way to implement such systems.

## Claims

1. A method for executing a managed application that calls a procedure in a native library comprising:
storing a reference associated with data to allow the data to be passed from the managed application executing in a virtual machine compatible with a first instruction set architecture (ISA) platform to the procedure in the native library, the procedure in the native library compatible with a second ISA platform different from the first ISA platform;
executing the procedure in the native library; and
when the data is called for by the procedure in the native library, retrieving the reference associated with the data, the reference stored in a data marshalling table and comprising first data location information compatible with the first ISA platform, the native library using second data location information compatible with the second ISA platform to call for the data, the second data location information comprising an address of the reference stored in the data marshalling table, the address being passed to the procedure in the native library, the reference being retrieved from the data marshalling table using the address.

2. A method as defined in claim 1 wherein retrieving the reference associated with the data comprises locating the reference stored at the address that was passed to the procedure.

3. A method as defined in claim 1 further comprising:
translating the called procedure; and
directing the procedure call to the translation of the called procedure.

4. A method as defined in claim 3 wherein the call to the procedure is directed by a stub function.

5. A method as defined in claim 1 wherein the managed application is at least one of a java application or a C# application.

6. A method as defined in claim 1 wherein the managed application is executed by a managed runtime environment that is associated with an instruction set architecture that is the same as a platform on which the managed runtime environment is executed.

7. An article of manufacture storing machine readable instructions that, when executed, cause a machine to:
store a reference associated with data to allow the data to be passed from the managed application executing in a virtual machine compatible with a first instruction set architecture (ISA) platform to the procedure in the native library, the procedure in the native library compatible with a second ISA platform different from the first ISA platform;
execute the procedure in the native library; and
retrieve the reference associated with the data, the reference stored in a data marshalling table and comprising first data location information compatible with the first ISA platform, when the data is called for by the procedure in the native library, the native library using second data location information compatible with the second ISA platform to call for the data, the second data location information comprising an address of the reference stored in the data marshalling table, the address being passed to the procedure in the native library, the reference being retrieved from the data marshalling table using the address.

8. An article of manufacture as defined in claim 7 wherein the machine readable instructions further cause the machine to locate the reference stored at the address that was passed to the procedure.

9. An article of manufacture as defined in claim 7 wherein the machine readable instructions further cause the machine to:
translate the called procedure; and
direct the procedure call to the translation of the called procedure.

10. An article of manufacture as defined in claim 9 wherein the machine readable instructions further cause the machine to direct the call to the procedure with a stub function.

11. An article of manufacture as defined in claim 7 wherein the managed application is at least one of a java application or a C# application.

12. An article of manufacture as defined in claim 9 wherein the procedure is translated by an IA-32 Execution Layer.

13. An apparatus to execute a managed application that calls a procedure in a native library comprising:
an interface implemented by at least one of hardware or a computer processor, the interface to store a reference associated with data to allow the data to be passed from the managed application executing in a virtual machine compatible with a first instruction set architecture (ISA) platform to the procedure in the native library, the procedure in the native library being compatible with a second ISA platform different from the first ISA platform, the interface to retrieve the reference associated with the data, the reference stored in a data marshalling table and comprising first data location information compatible with the first ISA platform, when the data is called for by the procedure in the native library, the native library using second data location information compatible with the second ISA platform to call for the data, the second data location information comprising an address of the reference stored in the data marshalling table, the address being passed to the procedure in the native library, the reference being retrieved from the data marshalling table using the address; and
a translator capable of executing the procedure in the native library.

14. An apparatus as defined in claim 13 wherein the interface is further capable of locating the reference stored at the address that was passed to the procedure.

15. An apparatus as defined in claim 13 wherein the translator is further capable of translating the called procedure.

16. An apparatus as defined in claim 15 wherein the interface is further capable of directing the procedure call to the translation of the called procedure.

17. An apparatus as defined in claim 16 further comprising a stub function that is capable of directing the procedure call to the translation of the called procedure.

18. An apparatus as defined in claim 13 wherein the managed application is at least one of a java application or a C# application.

19. An apparatus as defined in claim 13 wherein the translator is an IA-32 Execution Layer.