eeprom.c

轻量嵌入JVM,可用于掌上设备手机等手持消息设备．

/**************************************************************************************
*  EEProm.c
*
*  This file implements all native methods declared in the EEProm class.
*  IMPORTANT:
*       As there are many different types of EEPROMs this file contains only
*       function stubs assuming that wite operation is internally performed by
*       the EEPROM's internal circuitry.
*
*
* NOTE:
*  Be careful when accessing the native methods arguments. If native method is
*  declared as static then the first argoment starts at index zero. Non-static native
*  methods have arguments starting at index one, while argument at index zero is
*  a reference to the object on which the method is being invoked.
**************************************************************************************
*
* This file is covered by the GNU GPL with the following exception:
*   As a special exception, the copyright holders of this library give you permission
*   to link this library with independent modules to produce an executable, regardless
*   of the license terms of these independent modules, and to copy and distribute the
*   resulting executable under terms of your choice, provided that you also meet, for
*   each linked independent module, the terms and conditions of the license of that
*   module. An independent module is a module which is not derived from or based on
*   this library. If you modify this library, you may extend this exception to your
*   version of the library, but you are not obligated to do so. If you do not wish
*   to do so, delete this exception statement from your version.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY,  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL RTJ COMPUTING BE LIABLE FOR ANY CLAIM, DAMAGES
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Copyright (c) 2000-2002 RTJ Computing Pty. Ltd. All rights reserved.
**************************************************************************************/

#include "javavm.h"

extern vm_config_t vmconfig;

#define EEPROM_BASE      ((uint8 *)0x10000)
#define EEPROM_SIZE      0x8000


/****************************************************************************
* Verifies if the requested EEPROM memory area is valid.
*
* Java prototype:
*       protected static native boolean regionOk0(int start, int length);
*
****************************************************************************/
int16 javax_memory_EEProm_regionOk0(int32 param[], int32 *retval)
{
    *retval = false;
    if (param[0] >= EEPROM_BASE && (param[0] + param[1]) < (EEPROM_BASE + EEPROM_SIZE))
        *retval = true;
    return NO_EXCEP;
}

/****************************************************************************
* Writes a byte into memory.
*
* Java prototype:
*       protected static native boolean writeByte0(int address, int value);
*
****************************************************************************/
int16 javax_memory_EEProm_writeByte0(int32 param[], int32 *retval)
{
    *retval = true;
    *((uint8 *)param[0]) = (uint8)param[1];
    return NO_EXCEP;
}

/****************************************************************************
* Writes a short into memory MSB first.
*
* Java prototype:
*       protected static native boolean writeShort0(int address, int value);
*
****************************************************************************/
int16 javax_memory_EEProm_writeShort0(int32 param[], int32 *retval)
{
    *retval = true;
    *((uint8 *)param[0]) = (uint8)(param[1] >> 8);
    *((uint8 *)(param[0] + 1)) = (uint8)(param[1];
    return NO_EXCEP;
}

/****************************************************************************
* Writes an int  into memory MSB first.
*
* Java prototype:
*       protected static native boolean writeInt0(int address, int value);
*
****************************************************************************/
int16 javax_memory_EEProm_writeInt0(int32 param[], int32 *retval)
{
    *retval = true;
    *((uint8 *)param[0]) = (uint8)(param[1] >> 24);
    *((uint8 *)(param[0] + 1)) = (uint8)(param[1] >> 16);
    *((uint8 *)(param[0] + 2)) = (uint8)(param[1] >> 8);
    *((uint8 *)(param[0] + 3)) = (uint8)param[1];
    return NO_EXCEP;
}

/****************************************************************************
* Writes a byte array into memory.
*
* Java prototype:
*       protected static native boolean writeBytes0(int address, byte[] src, int start, int length);
*
****************************************************************************/
int16 javax_memory_EEProm_writeBytes0(int32 param[], int32 *retval)
{
    uint8 *arr;
    int16 i;

    *retval = true;
    arr = (uint8 *)vmconfig.vmGetArray(param[1]);
    if (arr != NULL)
    {
        for (i=0; i < param[3] && *retval; i++)
            *((uint8 *)(param[0] + i)) = arr[(int16)param[2] + i]);
    }
    return NO_EXCEP;
}