constructor.c

C++ 编写的EROS RTOS

/*
 * Copyright (C) 1998, 1999, 2001, Jonathan S. Shapiro.
 *
 * This file is part of the EROS Operating System.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* A constructor is responsible for building program instances.  The
 * constructor holds copies of each entry of the constituents node. In
 * addition, it holds the target process' keeper key, address space
 * key, symbol table ke, and initial PC.
 *
 * BOOTSTRAP NOTE 1:
 * 
 * To simplify system image construction, the constructor does some
 * minimal analysis at startup time.  If KC_PROD_CON0 and KC_PROD_XCON
 * are not void, they are accepted as holding the product constituents,
 * and KC_DCC should hold the domain creator for the constituents.
 * 
 * If initial constituents are found, the factory startup code assumes
 * that the factory should be initially sealed, and that no holes beyond
 * those that are apparent from the initial constituents are present,
 * and that KC_DCC is the actual domain creator.
 */

#include <eros/target.h>
#include <eros/Invoke.h>
#include <eros/DiscrimKey.h>
#include <eros/ReturnerKey.h>
#include <eros/NodeKey.h>
#include <eros/ProcessKey.h>
#include <eros/Key.h>
#include <eros/StdKeyType.h>
#include <eros/ProcessState.h>
#include <domain/domdbg.h>
#include <domain/ConstructorKey.h>
#include <domain/ProcessCreatorKey.h>
#include <domain/PccKey.h>
#include <domain/ProtoSpace.h>
#include <domain/SpaceBankKey.h>
#include <domain/Runtime.h>

#include "constituents.h"

uint32_t __rt_unkept = 1;

#define KR_SCRATCH      KR_APP(0)
#define KR_RETURNER     KR_APP(1)
#define KR_OSTREAM      KR_APP(2)
#define KR_YIELDCRE     KR_APP(3)
#define KR_YIELDBITS    KR_APP(4)
#define KR_NEWDOM       KR_APP(5)

#define KR_PROD_CON0    KR_APP(6) /* product's constituents */
#define KR_PROD_XCON    KR_APP(7) /* product's extended constituents */
#define KR_RO_YIELDBITS KR_APP(8) /* product's extended constituents */

#define KR_ARG0    KR_ARG(0)
#define KR_ARG1    KR_ARG(1)
#define KR_ARG2    KR_ARG(2)

#if 0
#define KC_DISCRIM  0
#define KC_RETURNER 1
#define KC_OSTREAM  2
#define KC_DCC      3
#define KC_PROTOSPC 4
#define KC_MYDOMCRE 5
#define KC_PROD_CON0 14
#define KC_PROD_XCON 15
#endif

/* Extended Constituents: */
#define XCON_KEEPER     0
#define XCON_ADDRSPACE  1
#define XCON_SYMTAB     2
#define XCON_PC         3

#define DEBUG if (0)

typedef struct {
  int frozen;
  int has_holes;
} ConstructorInfo;

void
CheckDiscretion(uint32_t kr, ConstructorInfo *ci)
{
  uint32_t result;
  uint32_t keyInfo;
  uint32_t isDiscreet;
  
  node_copy(KR_CONSTIT, KC_DISCRIM, KR_SCRATCH);

  result = discrim_verify(KR_SCRATCH, kr, &isDiscreet);
  if (result == RC_OK && isDiscreet)
    return;

  node_copy(KR_CONSTIT, KC_YIELDCRE, KR_SCRATCH);

  result = proccre_amplify_gate(KR_SCRATCH, kr, KR_SCRATCH, 0, &keyInfo);

  if (result == RC_OK && keyInfo == 0) {
    uint32_t isDiscreet;
    /* This key is a requestor's key to a constructor. Ask the
       constructor if it is discreet */
    result = constructor_is_discreet(kr, &isDiscreet);
    if (result == RC_OK && isDiscreet)
      return;
  }

  ci->has_holes = 1;
}

void
InitConstructor(ConstructorInfo *ci)
{
  uint32_t result;
  uint32_t keyType;

  ci->frozen = 0;
  ci->has_holes = 0;
  
  node_copy(KR_CONSTIT, KC_OSTREAM, KR_OSTREAM);

  DEBUG kdprintf(KR_OSTREAM, "constructor init\n");
  
  node_copy(KR_CONSTIT, KC_PROD_CON0, KR_PROD_CON0);

  result = key_kt(KR_PROD_CON0, &keyType, 0);
  if (result != RC_Void) {
    /* This is an initially frozen constructor.  Use the provided
       constituents, and assume that KC_YIELDCRE already holds the
       proper domain creator. */
    node_copy(KR_CONSTIT, KC_YIELDCRE, KR_YIELDCRE);
    node_copy(KR_CONSTIT, KC_PROD_CON0, KR_PROD_CON0);
    node_copy(KR_CONSTIT, KC_PROD_XCON, KR_PROD_XCON);

    ci->frozen = 1;
  }
  else {
    /* Build a new domain creator for use in crafting products */

    /* use KR_YIELDCRE and KR_DISCRIM as scratch regs for a moment: */
    node_copy(KR_CONSTIT, KC_PCC, KR_YIELDCRE);
    node_copy(KR_SELF, ProcSched, KR_SCRATCH);

    {
      Message msg;

      msg.snd_key0 = KR_BANK;
      msg.snd_key1 = KR_SCRATCH;
      msg.snd_key2 = KR_VOID;
      msg.snd_key3 = KR_VOID;
      msg.snd_data = 0;
      msg.snd_len = 0;
      msg.snd_code = OC_PCC_CreateProcessCreator;
      msg.snd_invKey = KR_YIELDCRE;

      msg.rcv_key0 = KR_YIELDCRE;
      msg.rcv_key1 = KR_VOID;
      msg.rcv_key2 = KR_VOID;
      msg.rcv_key3 = KR_VOID;
      msg.rcv_len = 0;		/* no data returned */

      result = CALL(&msg);
      DEBUG kdprintf(KR_OSTREAM, "GOT DOMCRE Result is 0x%08x\n", result);
    }
  
    spcbank_buy_nodes(KR_BANK, 2, KR_PROD_CON0, KR_PROD_XCON, KR_VOID);
  }
    

  /* Create a runtime bits node appropriate for our yields: */
  spcbank_buy_nodes(KR_BANK, 1, KR_YIELDBITS, KR_VOID, KR_VOID);
  node_clone(KR_YIELDBITS, KR_RTBITS);
  node_swap(KR_YIELDBITS, RKT_CREATOR, KR_YIELDCRE, KR_VOID);

  /* Now make the yieldbits key read-only. */
  {
    uint16_t keyData;

    node_get_key_data(KR_YIELDBITS, &keyData);
    node_make_node_key(KR_YIELDBITS, SEGMODE_RO | EROS_PAGE_BLSS,
		       KR_RO_YIELDBITS); 
  }

  node_copy(KR_CONSTIT, KC_RETURNER, KR_RETURNER);
}

/* In spite of unorthodox fabrication, the constructor self-destructs
   in the usual way. */
void
Sepuku()
{
  /* FIX: giving up the constituent nodes breaks our products */
  
  /* Give up the first constituent node. */
  /* Give up the second constituent node */
  spcbank_return_node(KR_BANK, KR_PROD_CON0);
  spcbank_return_node(KR_BANK, KR_PROD_XCON);
  spcbank_return_node(KR_BANK, KR_YIELDBITS);

  /* node_copy(KR_CONSTIT, KC_MYDOMCRE, KR_DOMCRE); */
  node_copy(KR_CONSTIT, KC_PROTOSPACE, KR_PROD_CON0);

  spcbank_return_node(KR_BANK, KR_CONSTIT);

  /* Invoke the protospace with arguments indicating that we should be
     demolished as a small space domain */
  protospace_destroy(KR_RETURNER, KR_PROD_CON0, KR_SELF,
		     KR_CREATOR, KR_BANK, 1);
}

uint32_t
MakeNewProduct(Message *msg)
{
  uint32_t result;
  struct Registers regs;

  DEBUG kdprintf(KR_OSTREAM, "Making new product...\n");

  result = proccre_create_process(KR_YIELDCRE, KR_ARG0, KR_NEWDOM);
  if (result != RC_OK)
    return result;

  /* NOTE that if proccre_create_process succeeded, we know it's a good
     space bank. */
  
  /* Build a constiuents node, since we will need the scratch register
     later */
  result = spcbank_buy_nodes(KR_ARG0, 1, KR_SCRATCH, KR_VOID, KR_VOID);
  if (result != RC_OK)
    goto destroy_product;

  /* clone the product constituents into the new constituents node: */
  node_clone(KR_SCRATCH, KR_PROD_CON0);

  (void) process_swap_keyreg(KR_NEWDOM, KR_CONSTIT, KR_SCRATCH, KR_VOID);
  (void) process_swap_keyreg(KR_NEWDOM, KR_RTBITS, KR_RO_YIELDBITS, KR_VOID);

  DEBUG kdprintf(KR_OSTREAM, "Populate new domain\n");

  (void) node_copy(KR_CONSTIT, KC_PROTOSPACE, KR_SCRATCH);

  /* Install protospace into the domain root: */
  (void) process_swap(KR_NEWDOM, ProcAddrSpace, KR_SCRATCH, KR_VOID);

  DEBUG kdprintf(KR_OSTREAM, "Installed protospace\n");

  /* Install the schedule key into the domain: */
  (void) process_swap(KR_NEWDOM, ProcSched, KR_ARG1, KR_VOID);
  
  DEBUG kdprintf(KR_OSTREAM, "Installed sched\n");

  /* Keeper constructor to keeper slot */
  (void) node_copy(KR_PROD_XCON, XCON_KEEPER, KR_SCRATCH);
  (void) process_swap(KR_NEWDOM, ProcKeeper, KR_SCRATCH, KR_VOID);

  /* Fetch out the register values, mostly for the benefit of
     Retrieving the PC -- this prevents us from needing to hard-code
     the PC, which will inevitably change. */
  (void) process_get_regs(KR_NEWDOM, &regs);

  DEBUG kdprintf(KR_OSTREAM, "Got regs\n");

  /* Unless we set them otherwise, the register values are zero.  The
     PC has already been set.  We now need to initialize the stack
     pointer and the segment registers. */
  regs.CS = DOMAIN_CODE_SEG;
  regs.SS = DOMAIN_DATA_SEG;
  regs.DS = DOMAIN_DATA_SEG;
  regs.ES = DOMAIN_DATA_SEG;
  regs.FS = DOMAIN_DATA_SEG;
  regs.GS = DOMAIN_DATA_SEG;
  regs.pc = 0;			/* Place Holder!! */
  regs.EFLAGS = 0x200;