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/*$$HEADER*/

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/*                    H E A D E R   I N F O R M A T I O N                     */

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// Project Name                   : ORPSoCv2

// File Name                      : jp_vpi.c

// Prepared By                    : jb, jb@orsoc.se

// Project Start                  : 2009-05-01

/*$$COPYRIGHT NOTICE*/

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/*                                                                            */

/*                      C O P Y R I G H T   N O T I C E                       */

/*                                                                            */

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/*

  This library is free software; you can redistribute it and/or

  modify it under the terms of the GNU Lesser General Public

  License as published by the Free Software Foundation;

  version 2.1 of the License, a copy of which is available from

  http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt.

  This library is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public

  License along with this library; if not, write to the Free Software

  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

*/

/*$$DESCRIPTION*/

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/*                           D E S C R I P T I O N                            */

/*                                                                            */

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//

// Implements communication between verilog simulator and RSP server

//

//

/*

Functions used via the Verilog Procedural Interface (VPI), in a verilog

simulation of an OpenRISC processor, providing a means of communication to the

simulatin for a GDB stub.

The communication between the GDB stub and this module is via a "custom"

protocol, which is decoded into the verilog debug task module and the

appropriate transactions are performed with the debug interface inside the

OpenRISC design.

Operation:

See the verilog file containing the calls to the VPI tasks  we outline in this

file for exact details of how they are  used (debug_vpi_module.v), but

following is a brief outline of how it is meant to work.

The RSP GDB stub is initialised after compile via a VPI callback

(cbEndOfCompile). A process is forked off to run the RSP server, and IPC is via

pipes. Note: This is probably an extremely ineffecient way to do this as the

fork() creates a copy of the program, including it's ~200MB memory space, so

maybe a different method should be worked out for massive sims, but for smaller

OpenRISC designs on a power machine this is not a problem.

The verilog debug module polls for incoming commands from the GDB stub at a

#delay rate set in the verilog code.

The port which the GDB server runs on is #define'd in this file by

RSP_SERVER_PORT.

When a GDB connection is established, the state of the processor is downloaded

by GDB, so expect a slight delay after connection.

To close down the simulation gracefully, issue a "detach" command from GDB.

This will close the connection with the stub and will also send a message to

$finish the simulation.

Note: Simulation reset is untested, but should probably work OK.

Note: Reading uninitialised memory which returns Xs will break things.

Specifically, the CRC generation breaks, and then many other things. So to help

avoid hours of X tracing, ensure you're reading initialised space from GDB.

To Do:

* Comment this better! Sorry, it's a little lacking in this area.

* Block transfers (ie. what happens when "load"ing from GDB) ignore any bytes

  over the word boundary at the end of a transfer. Currently a warning printf

  will appear.

* Make the RSP server process not be a complete copy of the vvp image - ie.

  don't fork() in the sim, maybe compile and exec() a separate app for this.

*/

/* EXAMPLE

// Associate C Function with a New System Task

voi

d registerHelloSystfs() {

  s_vpi_systf_data task_data_s;

  p_vpi_systf_data task_data_p = &task_data_s;

  task_data_p->type = vpiSysTask;

  task_data_p->tfname = "$hello";

  task_data_p->calltf = hello;

  task_data_p->compiletf = 0;

  vpi_register_systf(task_data_p);

}

*/

/*

To associate your C function with a system task, create a

data structure of type s_vpi_systf_data and a pointer to

that structure. The vpi_systf_data data type is defined in

the vpi_user.h include file. Below is the data structure

of s_vpi_systf_data.

 typedef struct t_vpi_systf_data {

   PLI_INT32 type;     // vpiSysTask, vpiSysFunc - task not return val, Func does

   PLI_INT32 sysfunctype; // vpiSysTask, vpi[Int,Real,Time,Sized, SizedSigned]Func - if it's a func, this is the typ of return

   PLI_BYTE8 *tfname;  // First character must be `$'

   PLI_INT32 (*calltf)(PLI_BYTE8 *); //pointer to the function

   PLI_INT32 (*compiletf)(PLI_BYTE8 *); // pointer to a function that the simulator calls

                                        // when it's compiled - can be NULL

   PLI_INT32 (*sizetf)(PLI_BYTE8 *); // For sized function callbacks only, This field is a

                                     // pointer to a routine that returns the size, in bits,

                                     // of the value that the system task or function returns.

   PLI_BYTE8 *user_data; --optional extra data?

 } s_vpi_systf_data, *p_vpi_systf_data;

*/

/*$$CHANGE HISTORY*/

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/*                         C H A N G E  H I S T O R Y                         */

/*                                                                            */

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// Date         Version Description

//------------------------------------------------------------------------

// 090501               Imported code from "jp" VPI project             jb

//                      Changed to use pipes instead of sockets         jb

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <unistd.h>

#include <sys/types.h>

#include <sys/wait.h>

#include <sys/select.h>

#include <sys/poll.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <ctype.h>

#include <string.h>

#include <stdarg.h>

#include <stdint.h>

#include <signal.h>

#include <inttypes.h>

// VPI includes

#include <vpi_user.h>

#ifdef CDS_VPI

// Cadence ncverilog specific include

#include <vpi_user_cds.h>

#endif

// Includes for the RSP server side of things

#include "gdb.h"

#include "rsp-rtl_sim.h"

#include "rsp-vpi.h"

// Define the port we open the RSP server on

#define RSP_SERVER_PORT 50002

//Function to register the function which sets up the sockets interface

void register_init_rsp_server_functions() ;

// Function which sets up the socket interface

void init_rsp_server();

//install a callback on simulation reset which calls setup

void setup_reset_callbacks();

//install a callback on simulation compilation finish

void setup_endofcompile_callbacks();

//install a callback on simulation finish

void setup_finish_callbacks();

//callback function which closes and clears the socket file descriptors

// on simulation reset

void sim_reset_callback();

void sim_endofcompile_callback();

void sim_finish_callback();

void register_check_for_command();

void register_get_command_address();

void register_get_command_data();

void register_return_command_block_data();

void register_return_command_data();

void register_get_command_block_data();

void register_return_response();

void check_for_command();

void get_command_address();

void get_command_data();

void get_command_block_data();

void return_command_data();

void return_command_block_data();

void return_response();

#include <time.h>

uint32_t vpi_to_rsp_pipe[2]; // [0] - read, [1] - write

uint32_t rsp_to_vpi_pipe[2]; // [0] - read, [1] - write

uint32_t command_pipe[2]; // RSP end writes, VPI end reads ONLY

/* Global static to store the child rsp server PID if we want to kill it */

static pid_t rsp_server_child_pid = (pid_t) 0; // pid_t is just a signed int

/********************************************************************/

/* init_rsp_server

 *

 * Fork off the rsp server process

 *                                                                   /

/********************************************************************/

void init_rsp_server(){

  // First get the port number to start the RSP server on

  vpiHandle systfref, args_iter, argh;

  struct t_vpi_value argval;

  int value,i;

  int n;

  int portNum;

  char* send_buf;

  /*

  // Currently removed - ability to call $rsp_init_server() with a

  // port number as parameter. Hardcoded allows us to run this as

  // a callback after compiile (cbEndOfCompile)

  // Obtain a handle to the argument list

  systfref = vpi_handle(vpiSysTfCall, NULL);

  // Now call iterate with the vpiArgument parameter

  args_iter = vpi_iterate(vpiArgument, systfref);

  // get a handle on the object passed to the function

  argh = vpi_scan(args_iter);

  // now store the command value back in the sim

  argval.format = vpiIntVal;

  // Now set the data value

  vpi_get_value(argh, &argval);

  portNum = (int) argval.value.integer;

  // Cleanup and return

  vpi_free_object(args_iter);

  // We should now have our port number.

  */

  // Fork. Let the child run the RSP server

  pid_t pid;

  int rv;

  if(DBG_JP_VPI) printf("jp_vpi: init_rsp_server\n");

  // Setup pipes

  if(pipe(vpi_to_rsp_pipe) == -1)

    {

      perror("jp_vpi: init_rsp_server pipes");

      exit(1);

    }

  if(pipe(rsp_to_vpi_pipe) == -1)

    {

      perror("jp_vpi: init_rsp_server pipes");

      exit(1);

    }

  if(pipe(command_pipe) == -1)

    {

      perror("jp_vpi: init_rsp_server pipes");

      exit(1);

    }

  // Set command pipe to be non-blocking

#if defined (STRIDE) || (defined (pfa) && defined (HAVE_PTYS)) || defined (AIX)

  {

    int one = 1;

    ioctl (command_pipe[0], FIONBIO, &one);

  }

#endif

#ifdef O_NONBLOCK /* The POSIX way */

  fcntl (command_pipe[0], F_SETFL, O_NONBLOCK);

#elif defined (O_NDELAY)

  fcntl (command_pipe[0], F_SETFL, O_NDELAY);

#endif /* O_NONBLOCK */

  // Check on the child process. If it has not been started it will

  // be 0, else it will be something else and we'll just return

  if ((int) rsp_server_child_pid > 0)

    return;

  switch(pid=fork())

    {

    case -1:

      perror("fork");

      exit(1);

      break;

    case 0: // Child

      run_rsp_server(RSP_SERVER_PORT);

      // exit if it ever returns, which it shouldn't

      exit(0);

      break;

    default:

      //  We're the parent process, so continue on.

      rsp_server_child_pid = pid;

      break;

    }

  // Parent will only ever get this far...

  return;

}

void register_init_rsp_server_functions() {

  s_vpi_systf_data data = {vpiSysTask,

                           0,

                           "$init_rsp_server",

                           (void *)init_rsp_server,

                           0,

                           0,

                           0};

  vpi_register_systf(&data);

  return;

}

void print_command_string(unsigned char cmd)

{

  switch(cmd)

    {

    case 0x1 :

      printf("  TAP instruction register set\n");

      break;

    case 0x2 :

      printf("  set debug chain\n");

      break;

    case 0x3 :

      printf("  CPU control (stall/reset) reg write\n");

      break;

    case 0x4 :

      printf("  CPU control (stall/reset) reg read\n");

      break;

    case 0x5 :

      printf("  CPU reg write\n");

      break;

    case 0x6 :

      printf("  CPU reg read\n");

      break;

    case 0x7 :

      printf("  WB write\n");

      break;

    case 0x8 :

      printf("  WB read 32\n");

      break;

    case 0x9 :

      printf("  WB block write 32\n");

      break;

    case 0xa :

      printf("  WB block read 32\n");

      break;

    case 0xb :

      printf("  reset\n");

      break;

    case 0xc :

      printf("  read jtag id\n");

      break;

    case 0xd :

      printf("  detach\n");

      break;

    case 0xe :

      printf("  WB read 8\n");

      break;

    }

}

// See if there's anything on the FIFO for us

void check_for_command(char *userdata){

  vpiHandle systfref, args_iter, argh;

  struct t_vpi_value argval;

  int value,i;

  int n;

  unsigned char data;

  //if(DBG_JP_VPI) printf("check_for_command\n");

  //n = read(rsp_to_vpi_pipe[0], &data, 1);

  n = read(command_pipe[0], &data, 1);

  if ( ((n < 0) && (errno == EAGAIN)) || (n==0) )

    {

      // Nothing in the fifo this time, let's return

      return;

    }

  else if (n < 0)

    {

      // some sort of error

      perror("check_for_command");

      exit(1);

    }

  if (DBG_JP_VPI)

  {

    printf("jp_vpi: c = %x:",data);

    print_command_string(data);

    fflush(stdout);

  }

  // Return the command to the sim

  // Obtain a handle to the argument list

  systfref = vpi_handle(vpiSysTfCall, NULL);

  // Now call iterate with the vpiArgument parameter

  args_iter = vpi_iterate(vpiArgument, systfref);

  // get a handle on the variable passed to the function

  argh = vpi_scan(args_iter);

  // now store the command value back in the sim

  argval.format = vpiIntVal;

  // Now set the command value

  vpi_get_value(argh, &argval);

  argval.value.integer = (uint32_t) data;

  // And vpi_put_value() it back into the sim

  vpi_put_value(argh, &argval, NULL, vpiNoDelay);

  // Cleanup and return

  vpi_free_object(args_iter);

  n = write(vpi_to_rsp_pipe[1],&data,1);

  if (DBG_JP_VPI) printf("jp_vpi: r");

  if (DBG_JP_VPI) printf("\n");

  return;

}

void get_command_address(char *userdata){

  vpiHandle systfref, args_iter, argh;

  struct t_vpi_value argval;

  int value,i;

  int n;

  uint32_t data;

  char* recv_buf;

  recv_buf = (char *) &data; // cast data as our receive char buffer

  n = read(rsp_to_vpi_pipe[0],recv_buf,4);

  if (n<0)

    {

      //client has closed connection

      //attempt to close and return gracefully

      return;

    }

  if (DBG_JP_VPI) printf("jp_vpi: get_command_address adr=0x%.8x\n",data);

  // now put the address into the argument passed to the task

  // Obtain a handle to the argument list

  systfref = vpi_handle(vpiSysTfCall, NULL);

  // Now call iterate with the vpiArgument parameter

  args_iter = vpi_iterate(vpiArgument, systfref);

  // get a handle on the variable passed to the function

  argh = vpi_scan(args_iter);

  // now store the command value back in the sim

  argval.format = vpiIntVal;

  // Now set the address value

  vpi_get_value(argh, &argval);

  argval.value.integer = (uint32_t) data;

  // And vpi_put_value() it back into the sim

  vpi_put_value(argh, &argval, NULL, vpiNoDelay);

  // Cleanup and return

  vpi_free_object(args_iter);

   return;

}

void get_command_data(char *userdata){

  vpiHandle systfref, args_iter, argh;

  struct t_vpi_value argval;

  int value,i;

  int n = 0;

  uint32_t data;

  char* recv_buf;

  recv_buf = (char *) &data; // cast data as our receive char buffer

 read_command_data_again:

  n = read(rsp_to_vpi_pipe[0],recv_buf,4);

  if ((n < 4) && errno==EAGAIN)

    goto read_command_data_again;

  else if (n < 4)

    {

      printf("jp_vpi: get_command_data errno: %d\n",errno);

      perror("jp_vpi: get_command_data read failed");

    }

  if (DBG_JP_VPI) printf("jp_vpi: get_command_data = 0x%.8x\n",data);

  // Obtain a handle to the argument list

  systfref = vpi_handle(vpiSysTfCall, NULL);

  // Now call iterate with the vpiArgument parameter

  args_iter = vpi_iterate(vpiArgument, systfref);

  // get a handle on the variable passed to the function

  argh = vpi_scan(args_iter);

  // now store the command value back in the sim

  argval.format = vpiIntVal;

  // Now set the data value

  vpi_get_value(argh, &argval);

  argval.value.integer = (uint32_t) data;

  // And vpi_put_value() it back into the sim

  vpi_put_value(argh, &argval, NULL, vpiNoDelay);

  // Cleanup and return

  vpi_free_object(args_iter);

   return;

}

void get_command_block_data(){ // $get_command_block_data(length, mem_array)

  vpiHandle systfref, args_iter, argh;

  struct t_vpi_value argval;

  int value,i;

  int n;

  uint32_t data;

  uint32_t length;

  char* recv_buf;

  // Now setup the handles to verilog objects and check things

  // Obtain a handle to the argument list

  systfref = vpi_handle(vpiSysTfCall, NULL);

  // Now call iterate with the vpiArgument parameter

  args_iter = vpi_iterate(vpiArgument, systfref);

  // get a handle on the length variable

  argh = vpi_scan(args_iter);

  argval.format = vpiIntVal;

  // get the value for the length object

  vpi_get_value(argh, &argval);

  // now set length

  length = argval.value.integer;

  int num_words = length/4;

  //if((length % 4) != 0) vpi_printf("length of %d bytes is not exactly word-aligned\n",length);

  // If non-word aligned we throw away remainder

  int throw_away_bytes = length %4;

  int loaded_words = 0;

  if(DBG_JP_VPI)printf("jp_vpi: get_command_block_data: length=%d, num_words=%d\n",length,num_words);

  // now get a handle on the next object (memory array)

  argh = vpi_scan(args_iter);

  // check we got passed a memory (array of regs)

  if (!((vpi_get(vpiType, argh) == vpiMemory)

#ifdef MODELSIM_VPI

        || (vpi_get(vpiType, argh) == vpiRegArray)

#endif

        ))

    {

      vpi_printf("jp_vpi: ERROR: did not pass a memory to get_command_block_data\n");

      vpi_printf("jp_vpi: ERROR: was passed type %d\n", (int)vpi_get(vpiType, argh));

      return;

    }

  // check the memory we're writing into is big enough

  if (vpi_get(vpiSize, argh) < num_words )

    {

      vpi_printf("jp_vpi: ERROR: buffer passed to get_command_block_data too small. size is %d words, needs to be %d\n",

                 vpi_get(vpiSize, argh), num_words);

      return;

    }

  vpiHandle array_word;

  // Loop to load the words

  while (loaded_words < num_words) {

    recv_buf = (char *) &data;

    // blocking receive for data block

    n = read(rsp_to_vpi_pipe[0],recv_buf,4);

    // now get a handle on the current word we want in the array that was passed to us

    array_word = vpi_handle_by_index(argh, loaded_words);

    if (array_word != NULL)

      {

        argval.value.integer = (uint32_t) data;

        // And vpi_put_value() it back into the sim

        vpi_put_value(array_word, &argval, NULL, vpiNoDelay);

      }

    else

      return;

    loaded_words++;

  }

  // TODO: This is a quick fix, should be delt with properly!!

  if (throw_away_bytes)

    {

      //printf("reading off %d extra data bytes\n",throw_away_bytes);

      n = read(rsp_to_vpi_pipe[0],&data,throw_away_bytes);

      //printf("read off %d bytes \n",n);

    }

  // Cleanup and return

  vpi_free_object(args_iter);

  return;

}

void return_command_data(char *userdata){

  vpiHandle systfref, args_iter, argh;

  struct t_vpi_value argval;

  int value,i;

  int n, length;

  uint32_t data;

  char* send_buf;

  // Obtain a handle to the argument list

  systfref = vpi_handle(vpiSysTfCall, NULL);

  // Now call iterate with the vpiArgument parameter

  args_iter = vpi_iterate(vpiArgument, systfref);

  // get a handle on the length variable

  argh = vpi_scan(args_iter);

  argval.format = vpiIntVal;

  // get the value for the length object

  vpi_get_value(argh, &argval);

  // now set length

  length = argval.value.integer;

  // get a handle on the object passed to the function

  argh = vpi_scan(args_iter);

  // now store the command value back in the sim

  argval.format = vpiIntVal;

  // Now set the data value

  vpi_get_value(argh, &argval);

  data = (uint32_t) argval.value.integer;

  // Cleanup and return

  vpi_free_object(args_iter);

  if (DBG_JP_VPI) printf("jp_vpi: return_command_data %d bytes, 0x%.8x\n",length,data);