summaryrefslogtreecommitdiff
path: root/src/arch/sparc/process.cc
blob: d5a95e0c0c50721943520ec9f0493cb6685625ef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
/*
 * Copyright (c) 2003-2004 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Gabe Black
 *          Ali Saidi
 */

#include "arch/sparc/asi.hh"
#include "arch/sparc/handlers.hh"
#include "arch/sparc/isa_traits.hh"
#include "arch/sparc/process.hh"
#include "arch/sparc/types.hh"
#include "base/loader/object_file.hh"
#include "base/loader/elf_object.hh"
#include "base/misc.hh"
#include "cpu/thread_context.hh"
#include "mem/page_table.hh"
#include "mem/translating_port.hh"
#include "sim/system.hh"

using namespace std;
using namespace SparcISA;


SparcLiveProcess::SparcLiveProcess(const std::string &nm, ObjectFile *objFile,
        System *_system, int stdin_fd, int stdout_fd, int stderr_fd,
        std::vector<std::string> &argv, std::vector<std::string> &envp,
        const std::string &cwd,
        uint64_t _uid, uint64_t _euid, uint64_t _gid, uint64_t _egid,
        uint64_t _pid, uint64_t _ppid)
    : LiveProcess(nm, objFile, _system, stdin_fd, stdout_fd, stderr_fd,
        argv, envp, cwd, _uid, _euid, _gid, _egid, _pid, _ppid)
{

    // XXX all the below need to be updated for SPARC - Ali
    brk_point = objFile->dataBase() + objFile->dataSize() + objFile->bssSize();
    brk_point = roundUp(brk_point, VMPageSize);

    // Set pointer for next thread stack.  Reserve 8M for main stack.
    next_thread_stack_base = stack_base - (8 * 1024 * 1024);

    //Initialize these to 0s
    fillStart = 0;
    spillStart = 0;
}

void SparcLiveProcess::handleTrap(int trapNum, ThreadContext *tc)
{
    switch(trapNum)
    {
      case 0x03: //Flush window trap
        warn("Ignoring request to flush register windows.\n");
        break;
      default:
        panic("Unimplemented trap to operating system: trap number %#x.\n", trapNum);
    }
}

void
Sparc32LiveProcess::startup()
{
    argsInit(32 / 8, VMPageSize);

    //From the SPARC ABI

    //The process runs in user mode
    threadContexts[0]->setMiscRegWithEffect(MISCREG_PSTATE, 0x02);

    //Setup default FP state
    threadContexts[0]->setMiscReg(MISCREG_FSR, 0);

    threadContexts[0]->setMiscReg(MISCREG_TICK, 0);
    //
    /*
     * Register window management registers
     */

    //No windows contain info from other programs
    //threadContexts[0]->setMiscReg(MISCREG_OTHERWIN, 0);
    threadContexts[0]->setIntReg(NumIntArchRegs + 6, 0);
    //There are no windows to pop
    //threadContexts[0]->setMiscReg(MISCREG_CANRESTORE, 0);
    threadContexts[0]->setIntReg(NumIntArchRegs + 4, 0);
    //All windows are available to save into
    //threadContexts[0]->setMiscReg(MISCREG_CANSAVE, NWindows - 2);
    threadContexts[0]->setIntReg(NumIntArchRegs + 3, NWindows - 2);
    //All windows are "clean"
    //threadContexts[0]->setMiscReg(MISCREG_CLEANWIN, NWindows);
    threadContexts[0]->setIntReg(NumIntArchRegs + 5, NWindows);
    //Start with register window 0
    threadContexts[0]->setMiscReg(MISCREG_CWP, 0);
    //Always use spill and fill traps 0
    //threadContexts[0]->setMiscReg(MISCREG_WSTATE, 0);
    threadContexts[0]->setIntReg(NumIntArchRegs + 7, 0);
    //Set the trap level to 0
    threadContexts[0]->setMiscReg(MISCREG_TL, 0);
    //Set the ASI register to something fixed
    threadContexts[0]->setMiscReg(MISCREG_ASI, ASI_PRIMARY);
}

void
Sparc64LiveProcess::startup()
{
    argsInit(sizeof(IntReg), VMPageSize);

    //From the SPARC ABI

    //The process runs in user mode
    threadContexts[0]->setMiscRegWithEffect(MISCREG_PSTATE, 0x02);

    //Setup default FP state
    threadContexts[0]->setMiscReg(MISCREG_FSR, 0);

    threadContexts[0]->setMiscReg(MISCREG_TICK, 0);
    //
    /*
     * Register window management registers
     */

    //No windows contain info from other programs
    //threadContexts[0]->setMiscReg(MISCREG_OTHERWIN, 0);
    threadContexts[0]->setIntReg(NumIntArchRegs + 6, 0);
    //There are no windows to pop
    //threadContexts[0]->setMiscReg(MISCREG_CANRESTORE, 0);
    threadContexts[0]->setIntReg(NumIntArchRegs + 4, 0);
    //All windows are available to save into
    //threadContexts[0]->setMiscReg(MISCREG_CANSAVE, NWindows - 2);
    threadContexts[0]->setIntReg(NumIntArchRegs + 3, NWindows - 2);
    //All windows are "clean"
    //threadContexts[0]->setMiscReg(MISCREG_CLEANWIN, NWindows);
    threadContexts[0]->setIntReg(NumIntArchRegs + 5, NWindows);
    //Start with register window 0
    threadContexts[0]->setMiscReg(MISCREG_CWP, 0);
    //Always use spill and fill traps 0
    //threadContexts[0]->setMiscReg(MISCREG_WSTATE, 0);
    threadContexts[0]->setIntReg(NumIntArchRegs + 7, 0);
    //Set the trap level to 0
    threadContexts[0]->setMiscReg(MISCREG_TL, 0);
    //Set the ASI register to something fixed
    threadContexts[0]->setMiscReg(MISCREG_ASI, ASI_PRIMARY);
}

M5_32_auxv_t::M5_32_auxv_t(int32_t type, int32_t val)
{
    a_type = TheISA::htog(type);
    a_val = TheISA::htog(val);
}

M5_64_auxv_t::M5_64_auxv_t(int64_t type, int64_t val)
{
    a_type = TheISA::htog(type);
    a_val = TheISA::htog(val);
}

void
Sparc64LiveProcess::argsInit(int intSize, int pageSize)
{
    typedef M5_64_auxv_t auxv_t;
    Process::startup();

    string filename;
    if(argv.size() < 1)
        filename = "";
    else
        filename = argv[0];

    Addr alignmentMask = ~(intSize - 1);

    // load object file into target memory
    objFile->loadSections(initVirtMem);

    //These are the auxilliary vector types
    enum auxTypes
    {
        SPARC_AT_HWCAP = 16,
        SPARC_AT_PAGESZ = 6,
        SPARC_AT_CLKTCK = 17,
        SPARC_AT_PHDR = 3,
        SPARC_AT_PHENT = 4,
        SPARC_AT_PHNUM = 5,
        SPARC_AT_BASE = 7,
        SPARC_AT_FLAGS = 8,
        SPARC_AT_ENTRY = 9,
        SPARC_AT_UID = 11,
        SPARC_AT_EUID = 12,
        SPARC_AT_GID = 13,
        SPARC_AT_EGID = 14,
        SPARC_AT_SECURE = 23
    };

    enum hardwareCaps
    {
        M5_HWCAP_SPARC_FLUSH = 1,
        M5_HWCAP_SPARC_STBAR = 2,
        M5_HWCAP_SPARC_SWAP = 4,
        M5_HWCAP_SPARC_MULDIV = 8,
        M5_HWCAP_SPARC_V9 = 16,
        //This one should technically only be set
        //if there is a cheetah or cheetah_plus tlb,
        //but we'll use it all the time
        M5_HWCAP_SPARC_ULTRA3 = 32
    };

    const int64_t hwcap =
        M5_HWCAP_SPARC_FLUSH |
        M5_HWCAP_SPARC_STBAR |
        M5_HWCAP_SPARC_SWAP |
        M5_HWCAP_SPARC_MULDIV |
        M5_HWCAP_SPARC_V9 |
        M5_HWCAP_SPARC_ULTRA3;


    //Setup the auxilliary vectors. These will already have endian conversion.
    //Auxilliary vectors are loaded only for elf formatted executables.
    ElfObject * elfObject = dynamic_cast<ElfObject *>(objFile);
    if(elfObject)
    {
        //Bits which describe the system hardware capabilities
        auxv.push_back(auxv_t(SPARC_AT_HWCAP, hwcap));
        //The system page size
        auxv.push_back(auxv_t(SPARC_AT_PAGESZ, SparcISA::VMPageSize));
        //Defined to be 100 in the kernel source.
        //Frequency at which times() increments
        auxv.push_back(auxv_t(SPARC_AT_CLKTCK, 100));
        // For statically linked executables, this is the virtual address of the
        // program header tables if they appear in the executable image
        auxv.push_back(auxv_t(SPARC_AT_PHDR, elfObject->programHeaderTable()));
        // This is the size of a program header entry from the elf file.
        auxv.push_back(auxv_t(SPARC_AT_PHENT, elfObject->programHeaderSize()));
        // This is the number of program headers from the original elf file.
        auxv.push_back(auxv_t(SPARC_AT_PHNUM, elfObject->programHeaderCount()));
        //This is the address of the elf "interpreter", It should be set
        //to 0 for regular executables. It should be something else
        //(not sure what) for dynamic libraries.
        auxv.push_back(auxv_t(SPARC_AT_BASE, 0));
        //This is hardwired to 0 in the elf loading code in the kernel
        auxv.push_back(auxv_t(SPARC_AT_FLAGS, 0));
        //The entry point to the program
        auxv.push_back(auxv_t(SPARC_AT_ENTRY, objFile->entryPoint()));
        //Different user and group IDs
        auxv.push_back(auxv_t(SPARC_AT_UID, uid()));
        auxv.push_back(auxv_t(SPARC_AT_EUID, euid()));
        auxv.push_back(auxv_t(SPARC_AT_GID, gid()));
        auxv.push_back(auxv_t(SPARC_AT_EGID, egid()));
        //Whether to enable "secure mode" in the executable
        auxv.push_back(auxv_t(SPARC_AT_SECURE, 0));
    }

    //Figure out how big the initial stack needs to be

    // The unaccounted for 0 at the top of the stack
    int mysterious_size = intSize;

    //This is the name of the file which is present on the initial stack
    //It's purpose is to let the user space linker examine the original file.
    int file_name_size = filename.size() + 1;

    int env_data_size = 0;
    for (int i = 0; i < envp.size(); ++i) {
        env_data_size += envp[i].size() + 1;
    }
    int arg_data_size = 0;
    for (int i = 0; i < argv.size(); ++i) {
        arg_data_size += argv[i].size() + 1;
    }

    //The info_block needs to be padded so it's size is a multiple of the
    //alignment mask. Also, it appears that there needs to be at least some
    //padding, so if the size is already a multiple, we need to increase it
    //anyway.
    int info_block_size =
        (file_name_size +
        env_data_size +
        arg_data_size +
        intSize) & alignmentMask;

    int info_block_padding =
        info_block_size -
        file_name_size -
        env_data_size -
        arg_data_size;

    //Each auxilliary vector is two 8 byte words
    int aux_array_size = intSize * 2 * (auxv.size() + 1);

    int envp_array_size = intSize * (envp.size() + 1);
    int argv_array_size = intSize * (argv.size() + 1);

    int argc_size = intSize;
    int window_save_size = intSize * 16;

    int space_needed =
        mysterious_size +
        info_block_size +
        aux_array_size +
        envp_array_size +
        argv_array_size +
        argc_size +
        window_save_size;

    stack_min = stack_base - space_needed;
    stack_min &= alignmentMask;
    stack_size = stack_base - stack_min;

    // map memory
    pTable->allocate(roundDown(stack_min, pageSize),
                     roundUp(stack_size, pageSize));

    // map out initial stack contents
    Addr mysterious_base = stack_base - mysterious_size;
    Addr file_name_base = mysterious_base - file_name_size;
    Addr env_data_base = file_name_base - env_data_size;
    Addr arg_data_base = env_data_base - arg_data_size;
    Addr auxv_array_base = arg_data_base - aux_array_size - info_block_padding;
    Addr envp_array_base = auxv_array_base - envp_array_size;
    Addr argv_array_base = envp_array_base - argv_array_size;
    Addr argc_base = argv_array_base - argc_size;
#ifndef NDEBUG
    // only used in DPRINTF
    Addr window_save_base = argc_base - window_save_size;
#endif

    DPRINTF(Sparc, "The addresses of items on the initial stack:\n");
    DPRINTF(Sparc, "0x%x - file name\n", file_name_base);
    DPRINTF(Sparc, "0x%x - env data\n", env_data_base);
    DPRINTF(Sparc, "0x%x - arg data\n", arg_data_base);
    DPRINTF(Sparc, "0x%x - auxv array\n", auxv_array_base);
    DPRINTF(Sparc, "0x%x - envp array\n", envp_array_base);
    DPRINTF(Sparc, "0x%x - argv array\n", argv_array_base);
    DPRINTF(Sparc, "0x%x - argc \n", argc_base);
    DPRINTF(Sparc, "0x%x - window save\n", window_save_base);
    DPRINTF(Sparc, "0x%x - stack min\n", stack_min);

    // write contents to stack

    // figure out argc
    uint64_t argc = argv.size();
    uint64_t guestArgc = TheISA::htog(argc);

    //Write out the mysterious 0
    uint64_t mysterious_zero = 0;
    initVirtMem->writeBlob(mysterious_base,
            (uint8_t*)&mysterious_zero, mysterious_size);

    //Write the file name
    initVirtMem->writeString(file_name_base, filename.c_str());

    //Copy the aux stuff
    for(int x = 0; x < auxv.size(); x++)
    {
        initVirtMem->writeBlob(auxv_array_base + x * 2 * intSize,
                (uint8_t*)&(auxv[x].a_type), intSize);
        initVirtMem->writeBlob(auxv_array_base + (x * 2 + 1) * intSize,
                (uint8_t*)&(auxv[x].a_val), intSize);
    }
    //Write out the terminating zeroed auxilliary vector
    const uint64_t zero = 0;
    initVirtMem->writeBlob(auxv_array_base + 2 * intSize * auxv.size(),
            (uint8_t*)&zero, 2 * intSize);

    copyStringArray(envp, envp_array_base, env_data_base, initVirtMem);
    copyStringArray(argv, argv_array_base, arg_data_base, initVirtMem);

    initVirtMem->writeBlob(argc_base, (uint8_t*)&guestArgc, intSize);

    //Stuff the trap handlers into the processes address space.
    //Since the stack grows down and is the highest area in the processes
    //address space, we can put stuff above it and stay out of the way.
    int fillSize = sizeof(MachInst) * numFillInsts;
    int spillSize = sizeof(MachInst) * numSpillInsts;
    fillStart = stack_base;
    spillStart = fillStart + fillSize;
    initVirtMem->writeBlob(fillStart, (uint8_t*)fillHandler64, fillSize);
    initVirtMem->writeBlob(spillStart, (uint8_t*)spillHandler64, spillSize);

    //Set up the thread context to start running the process
    threadContexts[0]->setIntReg(ArgumentReg0, argc);
    threadContexts[0]->setIntReg(ArgumentReg1, argv_array_base);
    threadContexts[0]->setIntReg(StackPointerReg, stack_min - StackBias);

    Addr prog_entry = objFile->entryPoint();
    threadContexts[0]->setPC(prog_entry);
    threadContexts[0]->setNextPC(prog_entry + sizeof(MachInst));
    threadContexts[0]->setNextNPC(prog_entry + (2 * sizeof(MachInst)));

    //Align the "stack_min" to a page boundary.
    stack_min = roundDown(stack_min, pageSize);

//    num_processes++;
}

void
Sparc32LiveProcess::argsInit(int intSize, int pageSize)
{
    typedef M5_32_auxv_t auxv_t;
    Process::startup();

    string filename;
    if(argv.size() < 1)
        filename = "";
    else
        filename = argv[0];

    Addr alignmentMask = ~(intSize - 1);

    // load object file into target memory
    objFile->loadSections(initVirtMem);

    //These are the auxilliary vector types
    enum auxTypes
    {
        SPARC_AT_HWCAP = 16,
        SPARC_AT_PAGESZ = 6,
        SPARC_AT_CLKTCK = 17,
        SPARC_AT_PHDR = 3,
        SPARC_AT_PHENT = 4,
        SPARC_AT_PHNUM = 5,
        SPARC_AT_BASE = 7,
        SPARC_AT_FLAGS = 8,
        SPARC_AT_ENTRY = 9,
        SPARC_AT_UID = 11,
        SPARC_AT_EUID = 12,
        SPARC_AT_GID = 13,
        SPARC_AT_EGID = 14,
        SPARC_AT_SECURE = 23
    };

    enum hardwareCaps
    {
        M5_HWCAP_SPARC_FLUSH = 1,
        M5_HWCAP_SPARC_STBAR = 2,
        M5_HWCAP_SPARC_SWAP = 4,
        M5_HWCAP_SPARC_MULDIV = 8,
        M5_HWCAP_SPARC_V9 = 16,
        //This one should technically only be set
        //if there is a cheetah or cheetah_plus tlb,
        //but we'll use it all the time
        M5_HWCAP_SPARC_ULTRA3 = 32
    };

    const int64_t hwcap =
        M5_HWCAP_SPARC_FLUSH |
        M5_HWCAP_SPARC_STBAR |
        M5_HWCAP_SPARC_SWAP |
        M5_HWCAP_SPARC_MULDIV |
        M5_HWCAP_SPARC_V9 |
        M5_HWCAP_SPARC_ULTRA3;


    //Setup the auxilliary vectors. These will already have endian conversion.
    //Auxilliary vectors are loaded only for elf formatted executables.
    ElfObject * elfObject = dynamic_cast<ElfObject *>(objFile);
    if(elfObject)
    {
        //Bits which describe the system hardware capabilities
        auxv.push_back(auxv_t(SPARC_AT_HWCAP, hwcap));
        //The system page size
        auxv.push_back(auxv_t(SPARC_AT_PAGESZ, SparcISA::VMPageSize));
        //Defined to be 100 in the kernel source.
        //Frequency at which times() increments
        auxv.push_back(auxv_t(SPARC_AT_CLKTCK, 100));
        // For statically linked executables, this is the virtual address of the
        // program header tables if they appear in the executable image
        auxv.push_back(auxv_t(SPARC_AT_PHDR, elfObject->programHeaderTable()));
        // This is the size of a program header entry from the elf file.
        auxv.push_back(auxv_t(SPARC_AT_PHENT, elfObject->programHeaderSize()));
        // This is the number of program headers from the original elf file.
        auxv.push_back(auxv_t(SPARC_AT_PHNUM, elfObject->programHeaderCount()));
        //This is the address of the elf "interpreter", It should be set
        //to 0 for regular executables. It should be something else
        //(not sure what) for dynamic libraries.
        auxv.push_back(auxv_t(SPARC_AT_BASE, 0));
        //This is hardwired to 0 in the elf loading code in the kernel
        auxv.push_back(auxv_t(SPARC_AT_FLAGS, 0));
        //The entry point to the program
        auxv.push_back(auxv_t(SPARC_AT_ENTRY, objFile->entryPoint()));
        //Different user and group IDs
        auxv.push_back(auxv_t(SPARC_AT_UID, uid()));
        auxv.push_back(auxv_t(SPARC_AT_EUID, euid()));
        auxv.push_back(auxv_t(SPARC_AT_GID, gid()));
        auxv.push_back(auxv_t(SPARC_AT_EGID, egid()));
        //Whether to enable "secure mode" in the executable
        auxv.push_back(auxv_t(SPARC_AT_SECURE, 0));
    }

    //Figure out how big the initial stack needs to be

    // The unaccounted for 0 at the top of the stack
    int mysterious_size = intSize;

    //This is the name of the file which is present on the initial stack
    //It's purpose is to let the user space linker examine the original file.
    int file_name_size = filename.size() + 1;

    int env_data_size = 0;
    for (int i = 0; i < envp.size(); ++i) {
        env_data_size += envp[i].size() + 1;
    }
    int arg_data_size = 0;
    for (int i = 0; i < argv.size(); ++i) {
        arg_data_size += argv[i].size() + 1;
    }

    //The info_block needs to be padded so it's size is a multiple of the
    //alignment mask. Also, it appears that there needs to be at least some
    //padding, so if the size is already a multiple, we need to increase it
    //anyway.
    int info_block_size =
        (file_name_size +
        env_data_size +
        arg_data_size +
        intSize) & alignmentMask;

    int info_block_padding =
        info_block_size -
        file_name_size -
        env_data_size -
        arg_data_size;

    //Each auxilliary vector is two 8 byte words
    int aux_array_size = intSize * 2 * (auxv.size() + 1);

    int envp_array_size = intSize * (envp.size() + 1);
    int argv_array_size = intSize * (argv.size() + 1);

    int argc_size = intSize;
    int window_save_size = intSize * 16;

    int space_needed =
        mysterious_size +
        info_block_size +
        aux_array_size +
        envp_array_size +
        argv_array_size +
        argc_size +
        window_save_size;

    stack_min = stack_base - space_needed;
    stack_min &= alignmentMask;
    stack_size = stack_base - stack_min;

    // map memory
    pTable->allocate(roundDown(stack_min, pageSize),
                     roundUp(stack_size, pageSize));

    // map out initial stack contents
    Addr mysterious_base = stack_base - mysterious_size;
    Addr file_name_base = mysterious_base - file_name_size;
    Addr env_data_base = file_name_base - env_data_size;
    Addr arg_data_base = env_data_base - arg_data_size;
    Addr auxv_array_base = arg_data_base - aux_array_size - info_block_padding;
    Addr envp_array_base = auxv_array_base - envp_array_size;
    Addr argv_array_base = envp_array_base - argv_array_size;
    Addr argc_base = argv_array_base - argc_size;
#ifndef NDEBUG
    // only used in DPRINTF
    Addr window_save_base = argc_base - window_save_size;
#endif

    DPRINTF(Sparc, "The addresses of items on the initial stack:\n");
    DPRINTF(Sparc, "0x%x - file name\n", file_name_base);
    DPRINTF(Sparc, "0x%x - env data\n", env_data_base);
    DPRINTF(Sparc, "0x%x - arg data\n", arg_data_base);
    DPRINTF(Sparc, "0x%x - auxv array\n", auxv_array_base);
    DPRINTF(Sparc, "0x%x - envp array\n", envp_array_base);
    DPRINTF(Sparc, "0x%x - argv array\n", argv_array_base);
    DPRINTF(Sparc, "0x%x - argc \n", argc_base);
    DPRINTF(Sparc, "0x%x - window save\n", window_save_base);
    DPRINTF(Sparc, "0x%x - stack min\n", stack_min);

    // write contents to stack

    // figure out argc
    uint32_t argc = argv.size();
    uint32_t guestArgc = TheISA::htog(argc);

    //Write out the mysterious 0
    uint64_t mysterious_zero = 0;
    initVirtMem->writeBlob(mysterious_base,
            (uint8_t*)&mysterious_zero, mysterious_size);

    //Write the file name
    initVirtMem->writeString(file_name_base, filename.c_str());

    //Copy the aux stuff
    for(int x = 0; x < auxv.size(); x++)
    {
        initVirtMem->writeBlob(auxv_array_base + x * 2 * intSize,
                (uint8_t*)&(auxv[x].a_type), intSize);
        initVirtMem->writeBlob(auxv_array_base + (x * 2 + 1) * intSize,
                (uint8_t*)&(auxv[x].a_val), intSize);
    }
    //Write out the terminating zeroed auxilliary vector
    const uint64_t zero = 0;
    initVirtMem->writeBlob(auxv_array_base + 2 * intSize * auxv.size(),
            (uint8_t*)&zero, 2 * intSize);

    copyStringArray(envp, envp_array_base, env_data_base, initVirtMem, intSize);
    copyStringArray(argv, argv_array_base, arg_data_base, initVirtMem, intSize);

    initVirtMem->writeBlob(argc_base, (uint8_t*)&guestArgc, intSize);

    //Stuff the trap handlers into the processes address space.
    //Since the stack grows down and is the highest area in the processes
    //address space, we can put stuff above it and stay out of the way.
    int fillSize = sizeof(MachInst) * numFillInsts;
    int spillSize = sizeof(MachInst) * numSpillInsts;
    fillStart = stack_base;
    spillStart = fillStart + fillSize;
    initVirtMem->writeBlob(fillStart, (uint8_t*)fillHandler32, fillSize);
    initVirtMem->writeBlob(spillStart, (uint8_t*)spillHandler32, spillSize);

    //Set up the thread context to start running the process
    threadContexts[0]->setIntReg(ArgumentReg0, argc);
    threadContexts[0]->setIntReg(ArgumentReg1, argv_array_base);
    threadContexts[0]->setIntReg(StackPointerReg, stack_min);

    Addr prog_entry = objFile->entryPoint();
    threadContexts[0]->setPC(prog_entry);
    threadContexts[0]->setNextPC(prog_entry + sizeof(MachInst));
    threadContexts[0]->setNextNPC(prog_entry + (2 * sizeof(MachInst)));

    //Align the "stack_min" to a page boundary.
    stack_min = roundDown(stack_min, pageSize);

//    num_processes++;
}