fork.c

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/*****************************************************************************************
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 All rights reserved.

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 $Id$

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

#include <ubixos/fork.h>
#include <ubixos/types.h>
#include <ubixos/sched.h>
#include <ubixos/tty.h>
#include <ubixos/vitals.h>
#include <vmm/vmm.h>
#include <string.h>
#include <assert.h>

/*****************************************************************************************
 Functoin: static int fork_copyProcess(struct taskStruct *newProcess,long ebp,long edi,
             long esi, long none,long ebx,long ecx,long edx,long eip,long cs,long eflags,
             long esp,long ss)
 
 Desc: This function will copy a process

 Notes:

*****************************************************************************************/
/* Had to remove static though tihs function is only used in this file */
int fork_copyProcess(struct taskStruct *newProcess,long ebp,long edi,long esi,long none,long ebx,long ecx,long edx,long eip,long cs,long eflags,long esp,long ss) {
  volatile struct taskStruct * tmpProcPtr = newProcess;
  assert(newProcess);
  assert(_current);
  
  /* Set Up New Tasks Information */
  memcpy(newProcess->oInfo.cwd,_current->oInfo.cwd,1024);
  
  newProcess->tss.eip          = eip;
  newProcess->oInfo.vmStart    = _current->oInfo.vmStart;
  newProcess->term             = _current->term;
  newProcess->term->owner      = newProcess->id;
  newProcess->uid              = _current->uid;
  newProcess->gid              = _current->gid;
  newProcess->tss.back_link    = 0x0;
  newProcess->tss.esp0         = _current->tss.esp0;
  newProcess->tss.ss0          = 0x10;
  newProcess->tss.esp1         = 0x0;
  newProcess->tss.ss1          = 0x0;
  newProcess->tss.esp2         = 0x0;
  newProcess->tss.ss2          = 0x0;
  newProcess->tss.eflags       = eflags;
  newProcess->tss.eax          = 0x0;
  newProcess->tss.ebx          = ebx;
  newProcess->tss.ecx          = ecx;
  newProcess->tss.edx          = edx;
  newProcess->tss.esi          = esi;
  newProcess->tss.edi          = edi;
  newProcess->tss.ebp          = ebp;
  newProcess->tss.esp          = esp;
  newProcess->tss.cs           = cs & 0xFF;
  newProcess->tss.ss           = ss & 0xFF;
  newProcess->tss.ds           = _current->tss.ds & 0xFF;
  newProcess->tss.fs           = _current->tss.fs & 0xFF;
  newProcess->tss.gs           = _current->tss.gs & 0xFF;
  newProcess->tss.es           = _current->tss.es & 0xFF;
  newProcess->tss.ldt          = 0x18;
  newProcess->tss.trace_bitmap = 0x0000;
  newProcess->tss.io_map       = 0x8000;
  /* Create A Copy Of The VM Space For New Task */
  newProcess->tss.cr3 = (uInt32)vmmCopyVirtualSpace(newProcess->id);
  newProcess->state = FORK;
 
  /* Fix gcc optimization problems */
  while (tmpProcPtr->state == FORK) sched_yield();

  /* Return Id of Proccess */
  return(newProcess->id);
  }
  
/*****************************************************************************************
 Functoin: void sysFork();
 
 Desc: This function will fork a new task

 Notes:
 
   08/01/02 - This Seems To Be Working Fine However I'm Not Sure If I
              Chose The Best Path To Impliment It I Guess We Will See
              What The Future May Bring 

*****************************************************************************************/
asm(
  ".globl sysFork           \n"
  "sysFork:                 \n"
  "  xor   %eax,%eax        \n"
  "  call  schedNewTask     \n"
  "  testl %eax,%eax        \n"
  "  je fork_ret            \n"
  "  pushl %esi             \n"
  "  pushl %edi             \n"
  "  pushl %ebp             \n"
  "  pushl %eax             \n"
  "  call  fork_copyProcess \n"
  "  movl  %eax,(%ebx)      \n"
  "  addl  $16,%esp         \n"
  "fork_ret:                \n"
  "  ret                    \n"
  );

/***
 END
 ***/

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