Kernel/arch/x86/proc.c

   1 /*
   2  * AcessOS Microkernel Version
   3  * proc.c
   4  */
   5 #include <acess.h>
   6 #include <threads.h>
   7 #include <proc.h>
   8 #include <desctab.h>
   9 #include <mm_virt.h>
  10 #include <errno.h>
  11 #if USE_MP
  12 # include <mp.h>
  13 #endif
  14
  15 // === FLAGS ===
  16 #define DEBUG_TRACE_SWITCH      0
  17 #define DEBUG_DISABLE_DOUBLEFAULT       1
  18
  19 // === CONSTANTS ===
  20 #define SWITCH_MAGIC    0xFF5317C8      // FF SWITCH - There is no code in this area
  21 // Base is 1193182
  22 #define TIMER_BASE      1193182
  23 #define TIMER_DIVISOR   11932   //~100Hz
  24
  25 // === TYPES ===
  26 #if USE_MP
  27 typedef struct sCPU
  28 {
  29         Uint8   APICID;
  30         Uint8   State;  // 0: Unavaliable, 1: Idle, 2: Active
  31         Uint16  Resvd;
  32         tThread *Current;
  33         tThread *IdleThread;
  34 }       tCPU;
  35 #endif
  36
  37 // === IMPORTS ===
  38 extern tGDT     gGDT[];
  39 extern tIDT     gIDT[];
  40 extern void APWait(void);       // 16-bit AP pause code
  41 extern void APStartup(void);    // 16-bit AP startup code
  42 extern Uint     GetEIP(void);   // start.asm
  43 extern int      GetCPUNum(void);        // start.asm
  44 extern Uint32   gaInitPageDir[1024];    // start.asm
  45 extern char     Kernel_Stack_Top[];
  46 extern tShortSpinlock   glThreadListLock;
  47 extern int      giNumCPUs;
  48 extern int      giNextTID;
  49 extern tThread  gThreadZero;
  50 extern void     Isr8(void);     // Double Fault
  51 extern void     Proc_ReturnToUser(tVAddr Handler, Uint Argument, tVAddr KernelStack);
  52
  53 // === PROTOTYPES ===
  54 void    ArchThreads_Init(void);
  55 #if USE_MP
  56 void    MP_StartAP(int CPU);
  57 void    MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
  58 #endif
  59 void    Proc_Start(void);
  60 tThread *Proc_GetCurThread(void);
  61 void    Proc_ChangeStack(void);
  62  int    Proc_Clone(Uint *Err, Uint Flags);
  63 void    Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP);
  64 void    Proc_CallFaultHandler(tThread *Thread);
  65 void    Proc_Scheduler(int CPU);
  66
  67 // === GLOBALS ===
  68 // --- Multiprocessing ---
  69 #if USE_MP
  70 volatile int    giNumInitingCPUs = 0;
  71 tMPInfo *gMPFloatPtr = NULL;
  72 volatile Uint32 giMP_TimerCount;        // Start Count for Local APIC Timer
  73 tAPIC   *gpMP_LocalAPIC = NULL;
  74 Uint8   gaAPIC_to_CPU[256] = {0};
  75 tCPU    gaCPUs[MAX_CPUS];
  76 tTSS    gaTSSs[MAX_CPUS];       // TSS Array
  77  int    giProc_BootProcessorID = 0;
  78 #else
  79 tThread *gCurrentThread = NULL;
  80 tThread *gpIdleThread = NULL;
  81 #endif
  82 #if USE_PAE
  83 Uint32  *gPML4s[4] = NULL;
  84 #endif
  85 tTSS    *gTSSs = NULL;  // Pointer to TSS array
  86 tTSS    gTSS0 = {0};
  87 // --- Error Recovery ---
  88 char    gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
  89 tTSS    gDoubleFault_TSS = {
  90         .ESP0 = (Uint)&gaDoubleFaultStack[1024],
  91         .SS0 = 0x10,
  92         .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
  93         .EIP = (Uint)Isr8,
  94         .ESP = (Uint)&gaDoubleFaultStack[1024],
  95         .CS = 0x08,     .SS = 0x10,
  96         .DS = 0x10,     .ES = 0x10,
  97         .FS = 0x10,     .GS = 0x10,
  98 };
  99
 100 // === CODE ===
 101 /**
 102  * \fn void ArchThreads_Init(void)
 103  * \brief Starts the process scheduler
 104  */
 105 void ArchThreads_Init(void)
 106 {
 107         Uint    pos = 0;
 108
 109         #if USE_MP
 110         tMPTable        *mptable;
 111
 112         // Mark BSP as active
 113         gaCPUs[0].State = 2;
 114
 115         // -- Initialise Multiprocessing
 116         // Find MP Floating Table
 117         // - EBDA/Last 1Kib (640KiB)
 118         for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
 119                 if( *(Uint*)(pos) == MPPTR_IDENT ) {
 120                         Log("Possible %p", pos);
 121                         if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 122                         gMPFloatPtr = (void*)pos;
 123                         break;
 124                 }
 125         }
 126         // - Last KiB (512KiB base mem)
 127         if(!gMPFloatPtr) {
 128                 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
 129                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 130                                 Log("Possible %p", pos);
 131                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 132                                 gMPFloatPtr = (void*)pos;
 133                                 break;
 134                         }
 135                 }
 136         }
 137         // - BIOS ROM
 138         if(!gMPFloatPtr) {
 139                 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
 140                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 141                                 Log("Possible %p", pos);
 142                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 143                                 gMPFloatPtr = (void*)pos;
 144                                 break;
 145                         }
 146                 }
 147         }
 148
 149         // If the MP Table Exists, parse it
 150         if(gMPFloatPtr)
 151         {
 152                  int    i;
 153                 tMPTable_Ent    *ents;
 154                 Log("gMPFloatPtr = %p", gMPFloatPtr);
 155                 Log("*gMPFloatPtr = {");
 156                 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
 157                 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
 158                 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
 159                 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
 160                 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
 161                 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
 162                         gMPFloatPtr->Features[0],       gMPFloatPtr->Features[1],
 163                         gMPFloatPtr->Features[2],       gMPFloatPtr->Features[3],
 164                         gMPFloatPtr->Features[4]
 165                         );
 166                 Log("}");
 167
 168                 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
 169                 Log("mptable = %p", mptable);
 170                 Log("*mptable = {");
 171                 Log("\t.Sig = 0x%08x", mptable->Sig);
 172                 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
 173                 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
 174                 Log("\t.Checksum = 0x%02x", mptable->Checksum);
 175                 Log("\t.OEMID = '%8c'", mptable->OemID);
 176                 Log("\t.ProductID = '%8c'", mptable->ProductID);
 177                 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
 178                 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
 179                 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
 180                 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
 181                 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
 182                 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
 183                 Log("}");
 184
 185                 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
 186
 187                 ents = mptable->Entries;
 188                 giNumCPUs = 0;
 189
 190                 for( i = 0; i < mptable->EntryCount; i ++ )
 191                 {
 192                          int    entSize = 0;
 193                         switch( ents->Type )
 194                         {
 195                         case 0: // Processor
 196                                 entSize = 20;
 197                                 Log("%i: Processor", i);
 198                                 Log("\t.APICID = %i", ents->Proc.APICID);
 199                                 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
 200                                 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
 201                                 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
 202                                 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
 203
 204
 205                                 if( !(ents->Proc.CPUFlags & 1) ) {
 206                                         Log("DISABLED");
 207                                         break;
 208                                 }
 209
 210                                 // Check if there is too many processors
 211                                 if(giNumCPUs >= MAX_CPUS) {
 212                                         giNumCPUs ++;   // If `giNumCPUs` > MAX_CPUS later, it will be clipped
 213                                         break;
 214                                 }
 215
 216                                 // Initialise CPU Info
 217                                 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
 218                                 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
 219                                 gaCPUs[giNumCPUs].State = 0;
 220                                 giNumCPUs ++;
 221
 222                                 // Set BSP Variable
 223                                 if( ents->Proc.CPUFlags & 2 ) {
 224                                         giProc_BootProcessorID = giNumCPUs-1;
 225                                 }
 226
 227                                 break;
 228
 229                         #if DUMP_MP_TABLES
 230                         case 1: // Bus
 231                                 entSize = 8;
 232                                 Log("%i: Bus", i);
 233                                 Log("\t.ID = %i", ents->Bus.ID);
 234                                 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
 235                                 break;
 236                         case 2: // I/O APIC
 237                                 entSize = 8;
 238                                 Log("%i: I/O APIC", i);
 239                                 Log("\t.ID = %i", ents->IOAPIC.ID);
 240                                 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
 241                                 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
 242                                 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
 243                                 break;
 244                         case 3: // I/O Interrupt Assignment
 245                                 entSize = 8;
 246                                 Log("%i: I/O Interrupt Assignment", i);
 247                                 Log("\t.IntType = %i", ents->IOInt.IntType);
 248                                 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
 249                                 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
 250                                 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
 251                                 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
 252                                 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
 253                                 break;
 254                         case 4: // Local Interrupt Assignment
 255                                 entSize = 8;
 256                                 Log("%i: Local Interrupt Assignment", i);
 257                                 Log("\t.IntType = %i", ents->LocalInt.IntType);
 258                                 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
 259                                 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
 260                                 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
 261                                 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
 262                                 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
 263                                 break;
 264                         default:
 265                                 Log("%i: Unknown (%i)", i, ents->Type);
 266                                 break;
 267                         #endif
 268                         }
 269                         ents = (void*)( (Uint)ents + entSize );
 270                 }
 271
 272                 if( giNumCPUs > MAX_CPUS ) {
 273                         Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
 274                         giNumCPUs = MAX_CPUS;
 275                 }
 276                 gTSSs = gaTSSs;
 277         }
 278         else {
 279                 Log("No MP Table was found, assuming uniprocessor\n");
 280                 giNumCPUs = 1;
 281                 gTSSs = &gTSS0;
 282         }
 283         #else
 284         giNumCPUs = 1;
 285         gTSSs = &gTSS0;
 286         MM_FinishVirtualInit();
 287         #endif
 288
 289         #if !DEBUG_DISABLE_DOUBLEFAULT
 290         // Initialise Double Fault TSS
 291         gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
 292         gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
 293         gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
 294
 295         // Set double fault IDT to use the new TSS
 296         gIDT[8].OffsetLo = 0;
 297         gIDT[8].CS = 5<<3;
 298         gIDT[8].Flags = 0x8500;
 299         gIDT[8].OffsetHi = 0;
 300         #endif
 301
 302         // Set timer frequency
 303         outb(0x43, 0x34);       // Set Channel 0, Low/High, Rate Generator
 304         outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
 305         outb(0x40, (TIMER_DIVISOR>>8)&0xFF);    // High Byte
 306
 307         Log("Timer Frequency %i.%03i Hz",
 308                 TIMER_BASE/TIMER_DIVISOR,
 309                 ((Uint64)TIMER_BASE*1000/TIMER_DIVISOR)%1000
 310                 );
 311
 312         #if USE_MP
 313         // Get the count setting for APIC timer
 314         Log("Determining APIC Count");
 315         __asm__ __volatile__ ("sti");
 316         while( giMP_TimerCount == 0 )   __asm__ __volatile__ ("hlt");
 317         __asm__ __volatile__ ("cli");
 318         Log("APIC Count %i", giMP_TimerCount);
 319         {
 320                 Uint64  freq = giMP_TimerCount;
 321                 freq /= TIMER_DIVISOR;
 322                 freq *= TIMER_BASE;
 323                 if( (freq /= 1000) < 2*1000)
 324                         Log("Bus Frequency %i KHz", freq);
 325                 else if( (freq /= 1000) < 2*1000)
 326                         Log("Bus Frequency %i MHz", freq);
 327                 else if( (freq /= 1000) < 2*1000)
 328                         Log("Bus Frequency %i GHz", freq);
 329                 else
 330                         Log("Bus Frequency %i THz", freq);
 331         }
 332
 333         // Initialise Normal TSS(s)
 334         for(pos=0;pos<giNumCPUs;pos++)
 335         {
 336         #else
 337         pos = 0;
 338         #endif
 339                 gTSSs[pos].SS0 = 0x10;
 340                 gTSSs[pos].ESP0 = 0;    // Set properly by scheduler
 341                 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
 342                 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos]) >> 16) & 0xFFFF;
 343                 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
 344         #if USE_MP
 345         }
 346         #endif
 347
 348         // Load the BSP's TSS
 349         __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
 350         // Set Current Thread and CPU Number in DR0 and DR1
 351         __asm__ __volatile__ ("mov %0, %%db0"::"r"(&gThreadZero));
 352         __asm__ __volatile__ ("mov %0, %%db1"::"r"(0));
 353
 354         #if USE_MP
 355         gaCPUs[0].Current = &gThreadZero;
 356         #else
 357         gCurrentThread = &gThreadZero;
 358         #endif
 359         gThreadZero.CurCPU = 0;
 360
 361         #if USE_PAE
 362         gThreadZero.MemState.PDP[0] = 0;
 363         gThreadZero.MemState.PDP[1] = 0;
 364         gThreadZero.MemState.PDP[2] = 0;
 365         #else
 366         gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
 367         #endif
 368
 369         // Create Per-Process Data Block
 370         if( !MM_Allocate(MM_PPD_CFG) )
 371         {
 372                 Panic("OOM - No space for initiali Per-Process Config");
 373         }
 374
 375         // Change Stacks
 376         Proc_ChangeStack();
 377 }
 378
 379 #if USE_MP
 380 void MP_StartAP(int CPU)
 381 {
 382         Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
 383
 384         // Set location of AP startup code and mark for a warm restart
 385         *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
 386         *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
 387         outb(0x70, 0x0F);       outb(0x71, 0x0A);       // Set warm reset flag
 388         MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);   // Init IPI
 389
 390         // Delay
 391         inb(0x80); inb(0x80); inb(0x80); inb(0x80);
 392
 393         // TODO: Use a better address, preferably registered with the MM
 394         // - MM_AllocDMA mabye?
 395         // Create a far jump
 396         *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA;  // Far JMP
 397         *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0);     // IP
 398         *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF;       // CS
 399         // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
 400         // just filled)
 401         MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6);        // StartupIPI
 402
 403         giNumInitingCPUs ++;
 404 }
 405
 406 /**
 407  * \brief Send an Inter-Processor Interrupt
 408  * \param APICID        Processor's Local APIC ID
 409  * \param Vector        Argument of some kind
 410  * \param DeliveryMode  Type of signal?
 411  */
 412 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
 413 {
 414         Uint32  val;
 415
 416         // Hi
 417         val = (Uint)APICID << 24;
 418         Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
 419         gpMP_LocalAPIC->ICR[1].Val = val;
 420         // Low (and send)
 421         val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
 422         Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
 423         gpMP_LocalAPIC->ICR[0].Val = val;
 424 }
 425 #endif
 426
 427 /**
 428  * \fn void Proc_Start(void)
 429  * \brief Start process scheduler
 430  */
 431 void Proc_Start(void)
 432 {
 433         #if USE_MP
 434          int    i;
 435         #endif
 436
 437         #if USE_MP
 438         // Start APs
 439         for( i = 0; i < giNumCPUs; i ++ )
 440         {
 441                  int    tid;
 442                 if(i)   gaCPUs[i].Current = NULL;
 443
 444                 // Create Idle Task
 445                 if( (tid = Proc_Clone(0, 0)) == 0)
 446                 {
 447                         for(;;) HALT(); // Just yeilds
 448                 }
 449                 gaCPUs[i].IdleThread = Threads_GetThread(tid);
 450                 gaCPUs[i].IdleThread->ThreadName = "Idle Thread";
 451                 Threads_SetPriority( gaCPUs[i].IdleThread, -1 );        // Never called randomly
 452                 gaCPUs[i].IdleThread->Quantum = 1;      // 1 slice quantum
 453
 454
 455                 // Start the AP
 456                 if( i != giProc_BootProcessorID ) {
 457                         MP_StartAP( i );
 458                 }
 459         }
 460
 461         // BSP still should run the current task
 462         gaCPUs[0].Current = &gThreadZero;
 463
 464         // Start interrupts and wait for APs to come up
 465         Log("Waiting for APs to come up\n");
 466         __asm__ __volatile__ ("sti");
 467         while( giNumInitingCPUs )       __asm__ __volatile__ ("hlt");
 468         #else
 469         // Create Idle Task
 470         if(Proc_Clone(0, 0) == 0)
 471         {
 472                 gpIdleThread = Proc_GetCurThread();
 473                 gpIdleThread->ThreadName = "Idle Thread";
 474                 Threads_SetPriority( gpIdleThread, -1 );        // Never called randomly
 475                 gpIdleThread->Quantum = 1;      // 1 slice quantum
 476                 for(;;) HALT(); // Just yeilds
 477         }
 478
 479         // Set current task
 480         gCurrentThread = &gThreadZero;
 481
 482         // Start Interrupts (and hence scheduler)
 483         __asm__ __volatile__("sti");
 484         #endif
 485         MM_FinishVirtualInit();
 486 }
 487
 488 /**
 489  * \fn tThread *Proc_GetCurThread(void)
 490  * \brief Gets the current thread
 491  */
 492 tThread *Proc_GetCurThread(void)
 493 {
 494         #if USE_MP
 495         return gaCPUs[ GetCPUNum() ].Current;
 496         #else
 497         return gCurrentThread;
 498         #endif
 499 }
 500
 501 /**
 502  * \fn void Proc_ChangeStack(void)
 503  * \brief Swaps the current stack for a new one (in the proper stack reigon)
 504  */
 505 void Proc_ChangeStack(void)
 506 {
 507         Uint    esp, ebp;
 508         Uint    tmpEbp, oldEsp;
 509         Uint    curBase, newBase;
 510
 511         __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
 512         __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
 513
 514         oldEsp = esp;
 515
 516         // Create new KStack
 517         newBase = MM_NewKStack();
 518         // Check for errors
 519         if(newBase == 0) {
 520                 Panic("What the?? Unable to allocate space for initial kernel stack");
 521                 return;
 522         }
 523
 524         curBase = (Uint)&Kernel_Stack_Top;
 525
 526         LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
 527
 528         // Get ESP as a used size
 529         esp = curBase - esp;
 530         LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
 531         // Copy used stack
 532         memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
 533         // Get ESP as an offset in the new stack
 534         esp = newBase - esp;
 535         // Adjust EBP
 536         ebp = newBase - (curBase - ebp);
 537
 538         // Repair EBPs & Stack Addresses
 539         // Catches arguments also, but may trash stack-address-like values
 540         for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
 541         {
 542                 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
 543                         *(Uint*)tmpEbp += newBase - curBase;
 544         }
 545
 546         Proc_GetCurThread()->KernelStack = newBase;
 547
 548         __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
 549         __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
 550 }
 551
 552 /**
 553  * \fn int Proc_Clone(Uint *Err, Uint Flags)
 554  * \brief Clone the current process
 555  */
 556 int Proc_Clone(Uint *Err, Uint Flags)
 557 {
 558         tThread *newThread;
 559         tThread *cur = Proc_GetCurThread();
 560         Uint    eip, esp, ebp;
 561
 562         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 563         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 564
 565         newThread = Threads_CloneTCB(Err, Flags);
 566         if(!newThread)  return -1;
 567
 568         // Initialise Memory Space (New Addr space or kernel stack)
 569         if(Flags & CLONE_VM) {
 570                 newThread->MemState.CR3 = MM_Clone();
 571                 // Check for errors
 572                 if(newThread->MemState.CR3 == 0) {
 573                         Threads_Kill(newThread, -2);
 574                         return -1;
 575                 }
 576                 newThread->KernelStack = cur->KernelStack;
 577         } else {
 578                 Uint    tmpEbp, oldEsp = esp;
 579
 580                 // Set CR3
 581                 #if USE_PAE
 582                 # warning "PAE Unimplemented"
 583                 #else
 584                 newThread->MemState.CR3 = cur->MemState.CR3;
 585                 #endif
 586
 587                 // Create new KStack
 588                 newThread->KernelStack = MM_NewKStack();
 589                 // Check for errors
 590                 if(newThread->KernelStack == 0) {
 591                         Threads_Kill(newThread, -2);
 592                         return -1;
 593                 }
 594
 595                 // Get ESP as a used size
 596                 esp = cur->KernelStack - esp;
 597                 // Copy used stack
 598                 memcpy( (void*)(newThread->KernelStack - esp), (void*)(cur->KernelStack - esp), esp );
 599                 // Get ESP as an offset in the new stack
 600                 esp = newThread->KernelStack - esp;
 601                 // Adjust EBP
 602                 ebp = newThread->KernelStack - (cur->KernelStack - ebp);
 603
 604                 // Repair EBPs & Stack Addresses
 605                 // Catches arguments also, but may trash stack-address-like values
 606                 for(tmpEbp = esp; tmpEbp < newThread->KernelStack; tmpEbp += 4)
 607                 {
 608                         if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < cur->KernelStack)
 609                                 *(Uint*)tmpEbp += newThread->KernelStack - cur->KernelStack;
 610                 }
 611         }
 612
 613         // Save core machine state
 614         newThread->SavedState.ESP = esp;
 615         newThread->SavedState.EBP = ebp;
 616         eip = GetEIP();
 617         if(eip == SWITCH_MAGIC) {
 618                 __asm__ __volatile__ ("mov %0, %%db0" : : "r" (newThread) );
 619                 #if USE_MP
 620                 // ACK the interrupt
 621                 if( GetCPUNum() )
 622                         gpMP_LocalAPIC->EOI.Val = 0;
 623                 else
 624                 #endif
 625                         outb(0x20, 0x20);       // ACK Timer and return as child
 626                 __asm__ __volatile__ ("sti");   // Restart interrupts
 627                 return 0;
 628         }
 629
 630         // Set EIP as parent
 631         newThread->SavedState.EIP = eip;
 632
 633         // Lock list and add to active
 634         Threads_AddActive(newThread);
 635
 636         return newThread->TID;
 637 }
 638
 639 /**
 640  * \fn int Proc_SpawnWorker(void)
 641  * \brief Spawns a new worker thread
 642  */
 643 int Proc_SpawnWorker(void)
 644 {
 645         tThread *new, *cur;
 646         Uint    eip, esp, ebp;
 647
 648         cur = Proc_GetCurThread();
 649
 650         // Create new thread
 651         new = Threads_CloneThreadZero();
 652         if(!new) {
 653                 Warning("Proc_SpawnWorker - Out of heap space!\n");
 654                 return -1;
 655         }
 656         // Create a new worker stack (in PID0's address space)
 657         // - The stack is relocated by this function
 658         new->KernelStack = MM_NewWorkerStack();
 659
 660         // Get ESP and EBP based in the new stack
 661         __asm__ __volatile__ ("mov %%esp, %0": "=r"(esp));
 662         __asm__ __volatile__ ("mov %%ebp, %0": "=r"(ebp));
 663         esp = new->KernelStack - (cur->KernelStack - esp);
 664         ebp = new->KernelStack - (cur->KernelStack - ebp);
 665
 666         // Save core machine state
 667         new->SavedState.ESP = esp;
 668         new->SavedState.EBP = ebp;
 669         eip = GetEIP();
 670         if(eip == SWITCH_MAGIC) {
 671                 __asm__ __volatile__ ("mov %0, %%db0" : : "r"(new));
 672                 #if USE_MP
 673                 // ACK the interrupt
 674                 if(GetCPUNum())
 675                         gpMP_LocalAPIC->EOI.Val = 0;
 676                 else
 677                 #endif
 678                         outb(0x20, 0x20);       // ACK Timer and return as child
 679                 __asm__ __volatile__ ("sti");   // Restart interrupts
 680                 return 0;
 681         }
 682
 683         // Set EIP as parent
 684         new->SavedState.EIP = eip;
 685         // Mark as active
 686         Threads_AddActive( new );
 687
 688         return new->TID;
 689 }
 690
 691 /**
 692  * \fn Uint Proc_MakeUserStack(void)
 693  * \brief Creates a new user stack
 694  */
 695 Uint Proc_MakeUserStack(void)
 696 {
 697          int    i;
 698         Uint    base = USER_STACK_TOP - USER_STACK_SZ;
 699
 700         // Check Prospective Space
 701         for( i = USER_STACK_SZ >> 12; i--; )
 702                 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
 703                         break;
 704
 705         if(i != -1)     return 0;
 706
 707         // Allocate Stack - Allocate incrementally to clean up MM_Dump output
 708         for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
 709         {
 710                 if( !MM_Allocate( base + (i<<12) ) )
 711                 {
 712                         Warning("OOM: Proc_MakeUserStack");
 713                         return 0;
 714                 }
 715         }
 716
 717         return base + USER_STACK_SZ;
 718 }
 719
 720 /**
 721  * \fn void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
 722  * \brief Starts a user task
 723  */
 724 void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize)
 725 {
 726         Uint    *stack = (void*)Proc_MakeUserStack();
 727          int    i;
 728         Uint    delta;
 729         Uint16  ss, cs;
 730
 731         //Log("stack = %p", stack);
 732
 733         // Copy Arguments
 734         stack -= DataSize/sizeof(*stack);
 735         memcpy( stack, ArgV, DataSize );
 736
 737         //Log("stack = %p", stack);
 738
 739         if( DataSize )
 740         {
 741                 // Adjust Arguments and environment
 742                 delta = (Uint)stack - (Uint)ArgV;
 743                 ArgV = (char**)stack;
 744                 for( i = 0; ArgV[i]; i++ )
 745                         ArgV[i] += delta;
 746                 i ++;
 747
 748                 // Do we care about EnvP?
 749                 if( EnvP ) {
 750                         EnvP = &ArgV[i];
 751                         for( i = 0; EnvP[i]; i++ )
 752                                 EnvP[i] += delta;
 753                 }
 754         }
 755
 756         // User Mode Segments
 757         ss = 0x23;      cs = 0x1B;
 758
 759         // Arguments
 760         *--stack = (Uint)EnvP;
 761         *--stack = (Uint)ArgV;
 762         *--stack = (Uint)ArgC;
 763         while(*Bases)
 764                 *--stack = *Bases++;
 765         *--stack = 0;   // Return Address
 766
 767         Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
 768 }
 769
 770 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
 771 {
 772         Uint    *stack = (void*)Stack;
 773         *--stack = SS;          //Stack Segment
 774         *--stack = Stack;       //Stack Pointer
 775         *--stack = Flags;       //EFLAGS (Resvd (0x2) and IF (0x20))
 776         *--stack = CS;          //Code Segment
 777         *--stack = IP;  //EIP
 778         //PUSHAD
 779         *--stack = 0xAAAAAAAA;  // eax
 780         *--stack = 0xCCCCCCCC;  // ecx
 781         *--stack = 0xDDDDDDDD;  // edx
 782         *--stack = 0xBBBBBBBB;  // ebx
 783         *--stack = 0xD1D1D1D1;  // edi
 784         *--stack = 0x54545454;  // esp - NOT POPED
 785         *--stack = 0x51515151;  // esi
 786         *--stack = 0xB4B4B4B4;  // ebp
 787         //Individual PUSHs
 788         *--stack = SS;  // ds
 789         *--stack = SS;  // es
 790         *--stack = SS;  // fs
 791         *--stack = SS;  // gs
 792
 793         __asm__ __volatile__ (
 794         "mov %%eax,%%esp;\n\t"  // Set stack pointer
 795         "pop %%gs;\n\t"
 796         "pop %%fs;\n\t"
 797         "pop %%es;\n\t"
 798         "pop %%ds;\n\t"
 799         "popa;\n\t"
 800         "iret;\n\t" : : "a" (stack));
 801         for(;;);
 802 }
 803
 804 /**
 805  * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 806  * \brief Demotes a process to a lower permission level
 807  * \param Err   Pointer to user's errno
 808  * \param Dest  New Permission Level
 809  * \param Regs  Pointer to user's register structure
 810  */
 811 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 812 {
 813          int    cpl = Regs->cs & 3;
 814         // Sanity Check
 815         if(Dest > 3 || Dest < 0) {
 816                 *Err = -EINVAL;
 817                 return -1;
 818         }
 819
 820         // Permission Check
 821         if(cpl > Dest) {
 822                 *Err = -EACCES;
 823                 return -1;
 824         }
 825
 826         // Change the Segment Registers
 827         Regs->cs = (((Dest+1)<<4) | Dest) - 8;
 828         Regs->ss = ((Dest+1)<<4) | Dest;
 829         // Check if the GP Segs are GDT, then change them
 830         if(!(Regs->ds & 4))     Regs->ds = ((Dest+1)<<4) | Dest;
 831         if(!(Regs->es & 4))     Regs->es = ((Dest+1)<<4) | Dest;
 832         if(!(Regs->fs & 4))     Regs->fs = ((Dest+1)<<4) | Dest;
 833         if(!(Regs->gs & 4))     Regs->gs = ((Dest+1)<<4) | Dest;
 834
 835         return 0;
 836 }
 837
 838 /**
 839  * \brief Calls a signal handler in user mode
 840  * \note Used for signals
 841  */
 842 void Proc_CallFaultHandler(tThread *Thread)
 843 {
 844         // Rewinds the stack and calls the user function
 845         // Never returns
 846         Proc_ReturnToUser( Thread->FaultHandler, Thread->CurFaultNum, Thread->KernelStack );
 847         for(;;);
 848 }
 849
 850 /**
 851  * \fn void Proc_Scheduler(int CPU)
 852  * \brief Swap current thread and clears dead threads
 853  */
 854 void Proc_Scheduler(int CPU)
 855 {
 856         Uint    esp, ebp, eip;
 857         tThread *thread;
 858
 859         // If the spinlock is set, let it complete
 860         if(IS_LOCKED(&glThreadListLock))        return;
 861
 862         // Get current thread
 863         #if USE_MP
 864         thread = gaCPUs[CPU].Current;
 865         #else
 866         thread = gCurrentThread;
 867         #endif
 868
 869         if( thread )
 870         {
 871                 // Reduce remaining quantum and continue timeslice if non-zero
 872                 if( thread->Remaining-- )
 873                         return;
 874                 // Reset quantum for next call
 875                 thread->Remaining = thread->Quantum;
 876
 877                 // Get machine state
 878                 __asm__ __volatile__ ( "mov %%esp, %0" : "=r" (esp) );
 879                 __asm__ __volatile__ ( "mov %%ebp, %0" : "=r" (ebp) );
 880                 eip = GetEIP();
 881                 if(eip == SWITCH_MAGIC) return; // Check if a switch happened
 882
 883                 // Save machine state
 884                 thread->SavedState.ESP = esp;
 885                 thread->SavedState.EBP = ebp;
 886                 thread->SavedState.EIP = eip;
 887         }
 888
 889         // Get next thread to run
 890         thread = Threads_GetNextToRun(CPU, thread);
 891
 892         // No avaliable tasks, just go into low power mode (idle thread)
 893         if(thread == NULL) {
 894                 #if USE_MP
 895                 thread = gaCPUs[CPU].IdleThread;
 896                 Log("CPU %i Running Idle Thread", CPU);
 897                 #else
 898                 thread = gpIdleThread;
 899                 #endif
 900         }
 901
 902         // Set current thread
 903         #if USE_MP
 904         gaCPUs[CPU].Current = thread;
 905         #else
 906         gCurrentThread = thread;
 907         #endif
 908
 909         #if DEBUG_TRACE_SWITCH
 910         Log("Switching to task %i, CR3 = 0x%x, EIP = %p",
 911                 thread->TID,
 912                 thread->MemState.CR3,
 913                 thread->SavedState.EIP
 914                 );
 915         #endif
 916
 917         #if USE_MP      // MP Debug
 918         Log("CPU = %i, Thread %p", CPU, thread);
 919         #endif
 920
 921         // Update Kernel Stack pointer
 922         gTSSs[CPU].ESP0 = thread->KernelStack-4;
 923
 924         #if 0
 925         if(thread->SavedState.ESP > 0xC0000000
 926         && thread->SavedState.ESP < thread->KernelStack-0x2000) {
 927                 Log_Warning("Proc", "Possible bad ESP %p (PID %i)", thread->SavedState.ESP);
 928         }
 929         #endif
 930
 931         #if USE_PAE
 932         # error "Todo: Implement PAE Address space switching"
 933         #else
 934         // Switch threads
 935         __asm__ __volatile__ (
 936                 "mov %4, %%cr3\n\t"     // Set address space
 937                 "mov %1, %%esp\n\t"     // Restore ESP
 938                 "mov %2, %%ebp\n\t"     // and EBP
 939                 "jmp *%3" : :   // And return to where we saved state (Proc_Clone or Proc_Scheduler)
 940                 "a"(SWITCH_MAGIC), "b"(thread->SavedState.ESP),
 941                 "d"(thread->SavedState.EBP), "c"(thread->SavedState.EIP),
 942                 "r"(thread->MemState.CR3)
 943                 );
 944         #endif
 945         for(;;);        // Shouldn't reach here
 946 }
 947
 948 // === EXPORTS ===
 949 EXPORT(Proc_SpawnWorker);