Running the RI

Invoke cref using cref.bat from JC_CLASSIC_HOME\bin

To run the RI:

Enter the following command (options are described in Table 10-2):
```
cref.bat [options]
```

Installer Mask

The development kit installer, the Java Card virtual machine interpreter, and the Java Card platform framework are built into the Installer mask. You can use it as-is to load and run applets. Other than the installer, it does not contain any applets.

The RI requires no other files to start proper interpretation and execution of the mask image's Java Card technology-based bytecode.

Obtaining Resource Consumption Statistics

Use the RI -z command line option to print memory usage at startup and at shutdown. Although memory usage statistics vary among Java Card RE implementations, this give you general idea of the amount of memory needed to install and execute an applet.

Note:

The Java Card API provides programmatic mechanisms for determining resource usage. For more information, see the javacard.framework.JCSystem.getAvailableMemory() method in the Application Programming Interface, Java Card Platform, Version 3.0.5, Classic Edition.

Getting Resource Statistics With the PhotoCard Sample

This example shows the resources used to download and execute a single application. These statistics can also be used to install a set of applications and execute several transactions.

The PhotoCard sample program downloads and installs an applet, illustrating using the large address space available in the 32-bit version of the RI (see PhotoCard Sample). The sample uses the large address space of the smart card's EEPROM memory to store up to four GIF images. Statistics are provided regarding the following resources: EEPROM, transaction buffer, stack usage, clear-on-reset RAM, and clear-on-deselect RAM. The statistics are printed twice, once at RI start up and once when it shuts down.

To get resource statistics with the photocard sample:

Enter the following command to run the PhotoCard sample program:
```
JC_CLASSIC_HOME\bin> cref_tdual -z -o e2p
```
Example 10-1 shows the output from running the PhotoCard sample program from the bin directory with the -z option.

Example 10-1 PhotoCard Sample Showing Resource Statistic Output

Java Card 3.0.5 C Reference Implementation Simulator
32-bit Address Space implementation - with cryptography support
T=1 / T=CL Dual interface APDU protocol (ISO 7816-4)
Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved.
 
Memory configuration -
        Type    Base    Size    Max Addr
        RAM     0x0     0x1000  0xfff
        ROM     0x2000  0xe000  0xffff
        E2P     0x10020 0xffe0  0x1ffff
 
        ROM Mask size =                 0xcec9 =        52937 bytes
        Highest ROM address in mask =   0xeec8 =        61128 bytes
        Space available in ROM =        0x1137 =        4407 bytes
EEPROM will be saved in file "e2p"
Mask has now been initialized for use
        0 bytecodes executed.
        Stack size: 00384 (0x0180) bytes,          00000 (0x0000) maximum used
        EEPROM use: 06994 (0x1b52) bytes consumed, 58510 (0xe48e) available
Transaction buffer: 00000 (0x0000) bytes consumed, 03560 (0x0de8) available
Clear-On-Reset RAM: 00000 (0x0000) bytes consumed, 00576 (0x0240) available
Clear-On-Dsel. RAM: 00000 (0x0000) bytes consumed, 00256 (0x0100) available
CREF was powered down.
   132232 bytecodes executed.
        Stack size: 00384 (0x0180) bytes,          00252 (0x00fc) maximum used
        EEPROM use: 09558 (0x2556) bytes consumed, 55946 (0xda8a) available
Transaction buffer: 00000 (0x0000) bytes consumed, 03560 (0x0de8) available
Clear-On-Reset RAM: 00198 (0x00c6) bytes consumed, 00378 (0x017a) available
Clear-On-Dsel. RAM: 00025 (0x0019) bytes consumed, 00231 (0x00e7) available
Temporary memory usage:
    Java stack: 0 bytes
    Clear on Deselect, channel space 0 : 0 bytes
    Clear on Deselect, channel space 1 : 0 bytes
    Clear on Deselect, channel space 2 : 0 bytes
    Clear on Deselect, channel space 3 : 0 bytes
    Clear on Deselect, channel space 4 : 0 bytes
    Clear on Deselect, channel space 5 : 0 bytes
    Clear on Deselect, channel space 6 : 0 bytes
    Clear on Deselect, channel space 7 : 0 bytes
    Clear on Reset: 0 bytes
 
C:\JCDK3.0.5\bin>cref_tdual -z -i e2p
Java Card 3.0.5 C Reference Implementation Simulator
32-bit Address Space implementation - with cryptography support
T=1 / T=CL Dual interface APDU protocol (ISO 7816-3)
Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved.
 
Memory configuration -
        Type    Base    Size    Max Addr
        RAM     0x0     0x1000  0xfff
        ROM     0x2000  0xe000  0xffff
        E2P     0x10020 0xffe0  0x1ffff
 
        ROM Mask size =                 0xcec9 =        52937 bytes
        Highest ROM address in mask =   0xeec8 =        61128 bytes
        Space available in ROM =        0x1137 =        4407 bytes
EEPROM (0xffe0 bytes) restored from file "e2p"
Using a pre-initialized Mask
        0 bytecodes executed.
        Stack size: 00384 (0x0180) bytes,          00000 (0x0000) maximum used
        EEPROM use: 09558 (0x2556) bytes consumed, 55946 (0xda8a) available
Transaction buffer: 00000 (0x0000) bytes consumed, 03560 (0x0de8) available
Clear-On-Reset RAM: 00198 (0x00c6) bytes consumed, 00378 (0x017a) available
Clear-On-Dsel. RAM: 00025 (0x0019) bytes consumed, 00231 (0x00e7) available
CREF was powered down.
  4624835 bytecodes executed.
        Stack size: 00384 (0x0180) bytes,          00250 (0x00fa) maximum used
        EEPROM use: 56993 (0xdea1) bytes consumed, 08511 (0x213f) available
Transaction buffer: 00000 (0x0000) bytes consumed, 03560 (0x0de8) available
Clear-On-Reset RAM: 00198 (0x00c6) bytes consumed, 00378 (0x017a) available
Clear-On-Dsel. RAM: 00125 (0x007d) bytes consumed, 00131 (0x0083) available
Temporary memory usage:
    Java stack: 0 bytes
    Clear on Deselect, channel space 0 : 0 bytes
    Clear on Deselect, channel space 1 : 0 bytes
    Clear on Deselect, channel space 2 : 0 bytes
    Clear on Deselect, channel space 3 : 0 bytes
    Clear on Deselect, channel space 4 : 0 bytes
    Clear on Deselect, channel space 5 : 0 bytes
    Clear on Deselect, channel space 6 : 0 bytes
    Clear on Deselect, channel space 7 : 0 bytes
    Clear on Reset: 0 bytes

Running the RI

Installer Mask

Obtaining Resource Consumption Statistics

Getting Resource Statistics With the PhotoCard Sample

Table of Contents

Java Card: 3 Platform Development Kit User Guide, Classic Edition