System Verilog DPI-C for pointer

SystemVerilog
1

Dear All,
I would like to allocate a buffer with only 32b-pointer at SystemVerilog for a 32b-pointer C system.
Following is my example code, printf at C shows the pointer always be 64b.
How can I generate buffer allocated at SystemVerilog with only 32b-pointer?
Many thanks~

SystemVerilog

import "DPI-C" function void C_FUNC(output int unsigned dwBaseAddr   [`MAX_SIZE]
                                      output chandle m_Buff);
  import "DPI-C" function chandle malloc(int unsigned size); 

  int unsigned    dwBaseAddr   [`MAX_SIZE];
  chandle         m_Buff;

  initial begin
      C_FUNC(dwBaseAddr);
      m_Buff = malloc(10);
  end

=======================================================
C code

void C_FUNC(int unsigned dwMemBuff
                  void* h_Buff)
{
    printf("[C] Addr = %16lx\n", dwMemBuff);
    printf("[C] Addr = %16lx\n", h_Buff);
}

=======================================================

2

In reply to vatics_r89162:

It’s not clear what you want to do. Please include a complete testcase.

To match your DPI-C import of C_FUNC, its header should be

void
C_FUNC(
    unsigned int* dwBaseAddr,
    void** m_Buff);
3

Thanks for your kindly reply, I describe my question more clearly as below.

module SIM_FUNC();
  import "DPI-C" function chandle malloc(input  int unsigned size);
  import "DPI-C" function void C_FUNC(output int unsigned  static_Buff[256],
                                        output chandle       Hdl_Buff);

  int unsigned  static_Buff   [256];
  chandle       Hdl_Buff;

  initial begin

      Hdl_Buff = malloc(512);
      C_FUNC(static_Buff, Hdl_Buff);
  end
endmodule:SIM_FUNC

==============================================================

void
C_FUNC(unsigned int* pStatic_Buff
       void** pHdl_Buff)
{
    unsigned int* ptC_Buff;   // In C system, pointer's bits only 32

    ptC_Buff = pStatic_Buff;

    printf("First data pStatic_Buff = %2x\n", pStatic_Buff[0]);  // It'ok, program ran smoothly
    printf("First data C_Buff       = %2x\n", ptC_Buff[0]);      // when program step this, it always gets segmentation fault


    //printf("[C_printf] SV_Addr = 0x%16lx, C_Addr = 0x%16lx \n", pStatic_Buff, ptC_Buff);
    //printf("[C_printf] Addr = %16lx\n", pHdl_Buff);
}

=================================================================
When I ran SIM_FUNC simulation with C_FUNC, it got segmentation fault.
After printf message,

[C_printf] SV_Addr = 0x2aad532c4000, C_Addr = 0x532c4000

It was easy to find that the buffer pointer(pStatic_Buff) at SIM_FUNC was 64 bit-width base, but in C_FUNC, ptC_Buff was declared as 32 bit-width. so C can’t identify ptC_Buff0.
In my C code, I have developed programs for 32 bit-width pointer. I would like to know if SV’s pointer could be as 32-bitwidth.

4

In reply to vatics_r89162:

You don’t declare pointers as being 32 or 64-bit; it’s determined how you compile your code, You need to make sure your C compiler and simulators are both using the same size pointers.

5

In reply to dave_59:

In reply to vatics_r89162:
You don’t declare pointers as being 32 or 64-bit; it’s determined how you compile your code, You need to make sure your C compiler and simulators are both using the same size pointers.

Actually, I force pointer type as 32-bit(company’s policy). So is it possible to force pointer type as 32-bit?