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 #include <hal_proc.h>
  15
  16 // === FLAGS ===
  17 #define DEBUG_TRACE_SWITCH      0
  18 #define DEBUG_DISABLE_DOUBLEFAULT       1
  19 #define DEBUG_VERY_SLOW_SWITCH  0
  20
  21 // === CONSTANTS ===
  22 // Base is 1193182
  23 #define TIMER_BASE      1193182
  24 #if DEBUG_VERY_SLOW_PERIOD
  25 # define TIMER_DIVISOR  1193    //~10Hz switch, with 10 quantum = 1s per thread
  26 #else
  27 # define TIMER_DIVISOR  11932   //~100Hz
  28 #endif
  29
  30 // === TYPES ===
  31 typedef struct sCPU
  32 {
  33         Uint8   APICID;
  34         Uint8   State;  // 0: Unavaliable, 1: Idle, 2: Active
  35         Uint16  Resvd;
  36         tThread *Current;
  37         tThread *IdleThread;
  38 }       tCPU;
  39
  40 // === IMPORTS ===
  41 extern tGDT     gGDT[];
  42 extern tIDT     gIDT[];
  43 extern void     APWait(void);   // 16-bit AP pause code
  44 extern void     APStartup(void);        // 16-bit AP startup code
  45 extern Uint     GetEIP(void);   // start.asm
  46 extern Uint     GetEIP_Sched(void);     // proc.asm
  47 extern void     NewTaskHeader(tThread *Thread, void *Fcn, int nArgs, ...);      // Actually takes cdecl args
  48 extern Uint     Proc_CloneInt(Uint *ESP, Uint32 *CR3);
  49 extern Uint32   gaInitPageDir[1024];    // start.asm
  50 extern char     Kernel_Stack_Top[];
  51 extern int      giNumCPUs;
  52 extern int      giNextTID;
  53 extern tThread  gThreadZero;
  54 extern void     Isr8(void);     // Double Fault
  55 extern void     Proc_ReturnToUser(tVAddr Handler, Uint Argument, tVAddr KernelStack);
  56 extern char     scheduler_return[];     // Return address in SchedulerBase
  57 extern char     IRQCommon[];    // Common IRQ handler code
  58 extern char     IRQCommon_handled[];    // IRQCommon call return location
  59 extern char     GetEIP_Sched_ret[];     // GetEIP call return location
  60 extern void     SwitchTasks(Uint NewSP, Uint *OldSP, Uint NewIP, Uint *OldIO, Uint CR3);
  61 extern void     Proc_InitialiseSSE(void);
  62 extern void     Proc_SaveSSE(Uint DestPtr);
  63 extern void     Proc_DisableSSE(void);
  64
  65 // === PROTOTYPES ===
  66 //void  ArchThreads_Init(void);
  67 #if USE_MP
  68 void    MP_StartAP(int CPU);
  69 void    MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode);
  70 #endif
  71 void    Proc_IdleThread(void *Ptr);
  72 //void  Proc_Start(void);
  73 //tThread       *Proc_GetCurThread(void);
  74 void    Proc_ChangeStack(void);
  75 // int  Proc_NewKThread(void (*Fcn)(void*), void *Data);
  76 // int  Proc_Clone(Uint *Err, Uint Flags);
  77 Uint    Proc_MakeUserStack(void);
  78 //void  Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **EnvP, int DataSize);
  79 void    Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP) NORETURN;
  80  int    Proc_Demote(Uint *Err, int Dest, tRegs *Regs);
  81 //void  Proc_CallFaultHandler(tThread *Thread);
  82 //void  Proc_DumpThreadCPUState(tThread *Thread);
  83 void    Proc_Scheduler(int CPU);
  84
  85 // === GLOBALS ===
  86 // --- Multiprocessing ---
  87 #if USE_MP
  88 volatile int    giNumInitingCPUs = 0;
  89 tMPInfo *gMPFloatPtr = NULL;
  90 volatile Uint32 giMP_TimerCount;        // Start Count for Local APIC Timer
  91 tAPIC   *gpMP_LocalAPIC = NULL;
  92 Uint8   gaAPIC_to_CPU[256] = {0};
  93  int    giProc_BootProcessorID = 0;
  94 tTSS    gaTSSs[MAX_CPUS];       // TSS Array
  95 #endif
  96 tCPU    gaCPUs[MAX_CPUS];
  97 tTSS    *gTSSs = NULL;  // Pointer to TSS array
  98 tTSS    gTSS0 = {0};
  99 // --- Error Recovery ---
 100 char    gaDoubleFaultStack[1024] __attribute__ ((section(".padata")));
 101 tTSS    gDoubleFault_TSS = {
 102         .ESP0 = (Uint)&gaDoubleFaultStack[1024],
 103         .SS0 = 0x10,
 104         .CR3 = (Uint)gaInitPageDir - KERNEL_BASE,
 105         .EIP = (Uint)Isr8,
 106         .ESP = (Uint)&gaDoubleFaultStack[1024],
 107         .CS = 0x08,     .SS = 0x10,
 108         .DS = 0x10,     .ES = 0x10,
 109         .FS = 0x10,     .GS = 0x10,
 110 };
 111
 112 // === CODE ===
 113 /**
 114  * \fn void ArchThreads_Init(void)
 115  * \brief Starts the process scheduler
 116  */
 117 void ArchThreads_Init(void)
 118 {
 119         Uint    pos = 0;
 120
 121         #if USE_MP
 122         tMPTable        *mptable;
 123
 124         // Mark BSP as active
 125         gaCPUs[0].State = 2;
 126
 127         // -- Initialise Multiprocessing
 128         // Find MP Floating Table
 129         // - EBDA/Last 1Kib (640KiB)
 130         for(pos = KERNEL_BASE|0x9F000; pos < (KERNEL_BASE|0xA0000); pos += 16) {
 131                 if( *(Uint*)(pos) == MPPTR_IDENT ) {
 132                         Log("Possible %p", pos);
 133                         if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 134                         gMPFloatPtr = (void*)pos;
 135                         break;
 136                 }
 137         }
 138         // - Last KiB (512KiB base mem)
 139         if(!gMPFloatPtr) {
 140                 for(pos = KERNEL_BASE|0x7F000; pos < (KERNEL_BASE|0x80000); pos += 16) {
 141                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 142                                 Log("Possible %p", pos);
 143                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 144                                 gMPFloatPtr = (void*)pos;
 145                                 break;
 146                         }
 147                 }
 148         }
 149         // - BIOS ROM
 150         if(!gMPFloatPtr) {
 151                 for(pos = KERNEL_BASE|0xE0000; pos < (KERNEL_BASE|0x100000); pos += 16) {
 152                         if( *(Uint*)(pos) == MPPTR_IDENT ) {
 153                                 Log("Possible %p", pos);
 154                                 if( ByteSum((void*)pos, sizeof(tMPInfo)) != 0 ) continue;
 155                                 gMPFloatPtr = (void*)pos;
 156                                 break;
 157                         }
 158                 }
 159         }
 160
 161         // If the MP Table Exists, parse it
 162         if(gMPFloatPtr)
 163         {
 164                  int    i;
 165                 tMPTable_Ent    *ents;
 166                 Log("gMPFloatPtr = %p", gMPFloatPtr);
 167                 Log("*gMPFloatPtr = {");
 168                 Log("\t.Sig = 0x%08x", gMPFloatPtr->Sig);
 169                 Log("\t.MPConfig = 0x%08x", gMPFloatPtr->MPConfig);
 170                 Log("\t.Length = 0x%02x", gMPFloatPtr->Length);
 171                 Log("\t.Version = 0x%02x", gMPFloatPtr->Version);
 172                 Log("\t.Checksum = 0x%02x", gMPFloatPtr->Checksum);
 173                 Log("\t.Features = [0x%02x,0x%02x,0x%02x,0x%02x,0x%02x]",
 174                         gMPFloatPtr->Features[0],       gMPFloatPtr->Features[1],
 175                         gMPFloatPtr->Features[2],       gMPFloatPtr->Features[3],
 176                         gMPFloatPtr->Features[4]
 177                         );
 178                 Log("}");
 179
 180                 mptable = (void*)( KERNEL_BASE|gMPFloatPtr->MPConfig );
 181                 Log("mptable = %p", mptable);
 182                 Log("*mptable = {");
 183                 Log("\t.Sig = 0x%08x", mptable->Sig);
 184                 Log("\t.BaseTableLength = 0x%04x", mptable->BaseTableLength);
 185                 Log("\t.SpecRev = 0x%02x", mptable->SpecRev);
 186                 Log("\t.Checksum = 0x%02x", mptable->Checksum);
 187                 Log("\t.OEMID = '%8c'", mptable->OemID);
 188                 Log("\t.ProductID = '%8c'", mptable->ProductID);
 189                 Log("\t.OEMTablePtr = %p'", mptable->OEMTablePtr);
 190                 Log("\t.OEMTableSize = 0x%04x", mptable->OEMTableSize);
 191                 Log("\t.EntryCount = 0x%04x", mptable->EntryCount);
 192                 Log("\t.LocalAPICMemMap = 0x%08x", mptable->LocalAPICMemMap);
 193                 Log("\t.ExtendedTableLen = 0x%04x", mptable->ExtendedTableLen);
 194                 Log("\t.ExtendedTableChecksum = 0x%02x", mptable->ExtendedTableChecksum);
 195                 Log("}");
 196
 197                 gpMP_LocalAPIC = (void*)MM_MapHWPages(mptable->LocalAPICMemMap, 1);
 198
 199                 ents = mptable->Entries;
 200                 giNumCPUs = 0;
 201
 202                 for( i = 0; i < mptable->EntryCount; i ++ )
 203                 {
 204                          int    entSize = 0;
 205                         switch( ents->Type )
 206                         {
 207                         case 0: // Processor
 208                                 entSize = 20;
 209                                 Log("%i: Processor", i);
 210                                 Log("\t.APICID = %i", ents->Proc.APICID);
 211                                 Log("\t.APICVer = 0x%02x", ents->Proc.APICVer);
 212                                 Log("\t.CPUFlags = 0x%02x", ents->Proc.CPUFlags);
 213                                 Log("\t.CPUSignature = 0x%08x", ents->Proc.CPUSignature);
 214                                 Log("\t.FeatureFlags = 0x%08x", ents->Proc.FeatureFlags);
 215
 216
 217                                 if( !(ents->Proc.CPUFlags & 1) ) {
 218                                         Log("DISABLED");
 219                                         break;
 220                                 }
 221
 222                                 // Check if there is too many processors
 223                                 if(giNumCPUs >= MAX_CPUS) {
 224                                         giNumCPUs ++;   // If `giNumCPUs` > MAX_CPUS later, it will be clipped
 225                                         break;
 226                                 }
 227
 228                                 // Initialise CPU Info
 229                                 gaAPIC_to_CPU[ents->Proc.APICID] = giNumCPUs;
 230                                 gaCPUs[giNumCPUs].APICID = ents->Proc.APICID;
 231                                 gaCPUs[giNumCPUs].State = 0;
 232                                 giNumCPUs ++;
 233
 234                                 // Set BSP Variable
 235                                 if( ents->Proc.CPUFlags & 2 ) {
 236                                         giProc_BootProcessorID = giNumCPUs-1;
 237                                 }
 238
 239                                 break;
 240
 241                         #if DUMP_MP_TABLES
 242                         case 1: // Bus
 243                                 entSize = 8;
 244                                 Log("%i: Bus", i);
 245                                 Log("\t.ID = %i", ents->Bus.ID);
 246                                 Log("\t.TypeString = '%6C'", ents->Bus.TypeString);
 247                                 break;
 248                         case 2: // I/O APIC
 249                                 entSize = 8;
 250                                 Log("%i: I/O APIC", i);
 251                                 Log("\t.ID = %i", ents->IOAPIC.ID);
 252                                 Log("\t.Version = 0x%02x", ents->IOAPIC.Version);
 253                                 Log("\t.Flags = 0x%02x", ents->IOAPIC.Flags);
 254                                 Log("\t.Addr = 0x%08x", ents->IOAPIC.Addr);
 255                                 break;
 256                         case 3: // I/O Interrupt Assignment
 257                                 entSize = 8;
 258                                 Log("%i: I/O Interrupt Assignment", i);
 259                                 Log("\t.IntType = %i", ents->IOInt.IntType);
 260                                 Log("\t.Flags = 0x%04x", ents->IOInt.Flags);
 261                                 Log("\t.SourceBusID = 0x%02x", ents->IOInt.SourceBusID);
 262                                 Log("\t.SourceBusIRQ = 0x%02x", ents->IOInt.SourceBusIRQ);
 263                                 Log("\t.DestAPICID = 0x%02x", ents->IOInt.DestAPICID);
 264                                 Log("\t.DestAPICIRQ = 0x%02x", ents->IOInt.DestAPICIRQ);
 265                                 break;
 266                         case 4: // Local Interrupt Assignment
 267                                 entSize = 8;
 268                                 Log("%i: Local Interrupt Assignment", i);
 269                                 Log("\t.IntType = %i", ents->LocalInt.IntType);
 270                                 Log("\t.Flags = 0x%04x", ents->LocalInt.Flags);
 271                                 Log("\t.SourceBusID = 0x%02x", ents->LocalInt.SourceBusID);
 272                                 Log("\t.SourceBusIRQ = 0x%02x", ents->LocalInt.SourceBusIRQ);
 273                                 Log("\t.DestLocalAPICID = 0x%02x", ents->LocalInt.DestLocalAPICID);
 274                                 Log("\t.DestLocalAPICIRQ = 0x%02x", ents->LocalInt.DestLocalAPICIRQ);
 275                                 break;
 276                         default:
 277                                 Log("%i: Unknown (%i)", i, ents->Type);
 278                                 break;
 279                         #endif
 280                         }
 281                         ents = (void*)( (Uint)ents + entSize );
 282                 }
 283
 284                 if( giNumCPUs > MAX_CPUS ) {
 285                         Warning("Too many CPUs detected (%i), only using %i of them", giNumCPUs, MAX_CPUS);
 286                         giNumCPUs = MAX_CPUS;
 287                 }
 288                 gTSSs = gaTSSs;
 289         }
 290         else {
 291                 Log("No MP Table was found, assuming uniprocessor\n");
 292                 giNumCPUs = 1;
 293                 gTSSs = &gTSS0;
 294         }
 295         #else
 296         giNumCPUs = 1;
 297         gTSSs = &gTSS0;
 298         #endif
 299
 300         #if !DEBUG_DISABLE_DOUBLEFAULT
 301         // Initialise Double Fault TSS
 302         gGDT[5].BaseLow = (Uint)&gDoubleFault_TSS & 0xFFFF;
 303         gGDT[5].BaseMid = (Uint)&gDoubleFault_TSS >> 16;
 304         gGDT[5].BaseHi = (Uint)&gDoubleFault_TSS >> 24;
 305
 306         // Set double fault IDT to use the new TSS
 307         gIDT[8].OffsetLo = 0;
 308         gIDT[8].CS = 5<<3;
 309         gIDT[8].Flags = 0x8500;
 310         gIDT[8].OffsetHi = 0;
 311         #endif
 312
 313         // Set timer frequency
 314         outb(0x43, 0x34);       // Set Channel 0, Low/High, Rate Generator
 315         outb(0x40, TIMER_DIVISOR&0xFF); // Low Byte of Divisor
 316         outb(0x40, (TIMER_DIVISOR>>8)&0xFF);    // High Byte
 317
 318         Log("Timer Frequency %i.%03i Hz",
 319                 TIMER_BASE/TIMER_DIVISOR,
 320                 ((Uint64)TIMER_BASE*1000/TIMER_DIVISOR)%1000
 321                 );
 322
 323         #if USE_MP
 324         // Get the count setting for APIC timer
 325         Log("Determining APIC Count");
 326         __asm__ __volatile__ ("sti");
 327         while( giMP_TimerCount == 0 )   __asm__ __volatile__ ("hlt");
 328         __asm__ __volatile__ ("cli");
 329         Log("APIC Count %i", giMP_TimerCount);
 330         {
 331                 Uint64  freq = giMP_TimerCount;
 332                 freq /= TIMER_DIVISOR;
 333                 freq *= TIMER_BASE;
 334                 if( (freq /= 1000) < 2*1000)
 335                         Log("Bus Frequency %i KHz", freq);
 336                 else if( (freq /= 1000) < 2*1000)
 337                         Log("Bus Frequency %i MHz", freq);
 338                 else if( (freq /= 1000) < 2*1000)
 339                         Log("Bus Frequency %i GHz", freq);
 340                 else
 341                         Log("Bus Frequency %i THz", freq);
 342         }
 343
 344         // Initialise Normal TSS(s)
 345         for(pos=0;pos<giNumCPUs;pos++)
 346         {
 347         #else
 348         pos = 0;
 349         #endif
 350                 gTSSs[pos].SS0 = 0x10;
 351                 gTSSs[pos].ESP0 = 0;    // Set properly by scheduler
 352                 gGDT[6+pos].BaseLow = ((Uint)(&gTSSs[pos])) & 0xFFFF;
 353                 gGDT[6+pos].BaseMid = ((Uint)(&gTSSs[pos]) >> 16) & 0xFFFF;
 354                 gGDT[6+pos].BaseHi = ((Uint)(&gTSSs[pos])) >> 24;
 355         #if USE_MP
 356         }
 357         #endif
 358
 359         // Load the BSP's TSS
 360         __asm__ __volatile__ ("ltr %%ax"::"a"(0x30));
 361         // Set Current Thread and CPU Number in DR0 and DR1
 362         __asm__ __volatile__ ("mov %0, %%db0"::"r"(&gThreadZero));
 363         __asm__ __volatile__ ("mov %0, %%db1"::"r"(0));
 364
 365         gaCPUs[0].Current = &gThreadZero;
 366         gThreadZero.CurCPU = 0;
 367
 368         gThreadZero.MemState.CR3 = (Uint)gaInitPageDir - KERNEL_BASE;
 369
 370         // Create Per-Process Data Block
 371         if( !MM_Allocate(MM_PPD_CFG) )
 372         {
 373                 Panic("OOM - No space for initial Per-Process Config");
 374         }
 375
 376         // Initialise SSE support
 377         Proc_InitialiseSSE();
 378
 379         // Change Stacks
 380         Proc_ChangeStack();
 381 }
 382
 383 #if USE_MP
 384 void MP_StartAP(int CPU)
 385 {
 386         Log("Starting AP %i (APIC %i)", CPU, gaCPUs[CPU].APICID);
 387
 388         // Set location of AP startup code and mark for a warm restart
 389         *(Uint16*)(KERNEL_BASE|0x467) = (Uint)&APWait - (KERNEL_BASE|0xFFFF0);
 390         *(Uint16*)(KERNEL_BASE|0x469) = 0xFFFF;
 391         outb(0x70, 0x0F);       outb(0x71, 0x0A);       // Set warm reset flag
 392         MP_SendIPI(gaCPUs[CPU].APICID, 0, 5);   // Init IPI
 393
 394         // Delay
 395         inb(0x80); inb(0x80); inb(0x80); inb(0x80);
 396
 397         // TODO: Use a better address, preferably registered with the MM
 398         // - MM_AllocDMA mabye?
 399         // Create a far jump
 400         *(Uint8*)(KERNEL_BASE|0x11000) = 0xEA;  // Far JMP
 401         *(Uint16*)(KERNEL_BASE|0x11001) = (Uint)&APStartup - (KERNEL_BASE|0xFFFF0);     // IP
 402         *(Uint16*)(KERNEL_BASE|0x11003) = 0xFFFF;       // CS
 403         // Send a Startup-IPI to make the CPU execute at 0x11000 (which we
 404         // just filled)
 405         MP_SendIPI(gaCPUs[CPU].APICID, 0x11, 6);        // StartupIPI
 406
 407         giNumInitingCPUs ++;
 408 }
 409
 410 /**
 411  * \brief Send an Inter-Processor Interrupt
 412  * \param APICID        Processor's Local APIC ID
 413  * \param Vector        Argument of some kind
 414  * \param DeliveryMode  Type of signal?
 415  */
 416 void MP_SendIPI(Uint8 APICID, int Vector, int DeliveryMode)
 417 {
 418         Uint32  val;
 419
 420         // Hi
 421         val = (Uint)APICID << 24;
 422         Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[1], val);
 423         gpMP_LocalAPIC->ICR[1].Val = val;
 424         // Low (and send)
 425         val = ((DeliveryMode & 7) << 8) | (Vector & 0xFF);
 426         Log("*%p = 0x%08x", &gpMP_LocalAPIC->ICR[0], val);
 427         gpMP_LocalAPIC->ICR[0].Val = val;
 428 }
 429 #endif
 430
 431 void Proc_IdleThread(void *Ptr)
 432 {
 433         tCPU    *cpu = Ptr;
 434         cpu->IdleThread->ThreadName = strdup("Idle Thread");
 435         Threads_SetPriority( cpu->IdleThread, -1 );     // Never called randomly
 436         cpu->IdleThread->Quantum = 1;   // 1 slice quantum
 437         for(;;) {
 438                 HALT();
 439                 Proc_Reschedule();
 440         }
 441 }
 442
 443 /**
 444  * \fn void Proc_Start(void)
 445  * \brief Start process scheduler
 446  */
 447 void Proc_Start(void)
 448 {
 449          int    tid;
 450         #if USE_MP
 451          int    i;
 452         #endif
 453
 454         #if USE_MP
 455         // Start APs
 456         for( i = 0; i < giNumCPUs; i ++ )
 457         {
 458                 if(i)   gaCPUs[i].Current = NULL;
 459
 460                 // Create Idle Task
 461                 tid = Proc_NewKThread(Proc_IdleThread, &gaCPUs[i]);
 462                 gaCPUs[i].IdleThread = Threads_GetThread(tid);
 463
 464                 // Start the AP
 465                 if( i != giProc_BootProcessorID ) {
 466                         MP_StartAP( i );
 467                 }
 468         }
 469
 470         // BSP still should run the current task
 471         gaCPUs[0].Current = &gThreadZero;
 472
 473         // Start interrupts and wait for APs to come up
 474         Log("Waiting for APs to come up\n");
 475         __asm__ __volatile__ ("sti");
 476         while( giNumInitingCPUs )       __asm__ __volatile__ ("hlt");
 477         #else
 478         // Create Idle Task
 479         tid = Proc_NewKThread(Proc_IdleThread, &gaCPUs[0]);
 480         gaCPUs[0].IdleThread = Threads_GetThread(tid);
 481
 482         // Set current task
 483         gaCPUs[0].Current = &gThreadZero;
 484
 485 //      while( gaCPUs[0].IdleThread == NULL )
 486 //              Threads_Yield();
 487
 488         // Start Interrupts (and hence scheduler)
 489         __asm__ __volatile__("sti");
 490         #endif
 491         MM_FinishVirtualInit();
 492 }
 493
 494 /**
 495  * \fn tThread *Proc_GetCurThread(void)
 496  * \brief Gets the current thread
 497  */
 498 tThread *Proc_GetCurThread(void)
 499 {
 500         #if USE_MP
 501         return gaCPUs[ GetCPUNum() ].Current;
 502         #else
 503         return gaCPUs[ 0 ].Current;
 504         #endif
 505 }
 506
 507 /**
 508  * \fn void Proc_ChangeStack(void)
 509  * \brief Swaps the current stack for a new one (in the proper stack reigon)
 510  */
 511 void Proc_ChangeStack(void)
 512 {
 513         Uint    esp, ebp;
 514         Uint    tmpEbp, oldEsp;
 515         Uint    curBase, newBase;
 516
 517         __asm__ __volatile__ ("mov %%esp, %0":"=r"(esp));
 518         __asm__ __volatile__ ("mov %%ebp, %0":"=r"(ebp));
 519
 520         oldEsp = esp;
 521
 522         // Create new KStack
 523         newBase = MM_NewKStack();
 524         // Check for errors
 525         if(newBase == 0) {
 526                 Panic("What the?? Unable to allocate space for initial kernel stack");
 527                 return;
 528         }
 529
 530         curBase = (Uint)&Kernel_Stack_Top;
 531
 532         LOG("curBase = 0x%x, newBase = 0x%x", curBase, newBase);
 533
 534         // Get ESP as a used size
 535         esp = curBase - esp;
 536         LOG("memcpy( %p, %p, 0x%x )", (void*)(newBase - esp), (void*)(curBase - esp), esp );
 537         // Copy used stack
 538         memcpy( (void*)(newBase - esp), (void*)(curBase - esp), esp );
 539         // Get ESP as an offset in the new stack
 540         esp = newBase - esp;
 541         // Adjust EBP
 542         ebp = newBase - (curBase - ebp);
 543
 544         // Repair EBPs & Stack Addresses
 545         // Catches arguments also, but may trash stack-address-like values
 546         for(tmpEbp = esp; tmpEbp < newBase; tmpEbp += 4)
 547         {
 548                 if(oldEsp < *(Uint*)tmpEbp && *(Uint*)tmpEbp < curBase)
 549                         *(Uint*)tmpEbp += newBase - curBase;
 550         }
 551
 552         Proc_GetCurThread()->KernelStack = newBase;
 553
 554         __asm__ __volatile__ ("mov %0, %%esp"::"r"(esp));
 555         __asm__ __volatile__ ("mov %0, %%ebp"::"r"(ebp));
 556 }
 557
 558 void Proc_ClearThread(tThread *Thread)
 559 {
 560         Log_Warning("Proc", "TODO: Nuke address space etc");
 561         if(Thread->SavedState.SSE) {
 562                 free(Thread->SavedState.SSE);
 563                 Thread->SavedState.SSE = NULL;
 564         }
 565 }
 566
 567 int Proc_NewKThread(void (*Fcn)(void*), void *Data)
 568 {
 569         Uint    esp;
 570         tThread *newThread, *cur;
 571
 572         cur = Proc_GetCurThread();
 573         newThread = Threads_CloneTCB(0);
 574         if(!newThread)  return -1;
 575
 576         // Set CR3
 577         newThread->MemState.CR3 = cur->MemState.CR3;
 578
 579         // Create new KStack
 580         newThread->KernelStack = MM_NewKStack();
 581         // Check for errors
 582         if(newThread->KernelStack == 0) {
 583                 free(newThread);
 584                 return -1;
 585         }
 586
 587         esp = newThread->KernelStack;
 588         *(Uint*)(esp-=4) = (Uint)Data;  // Data (shadowed)
 589         *(Uint*)(esp-=4) = 1;   // Number of params
 590         *(Uint*)(esp-=4) = (Uint)Fcn;   // Function to call
 591         *(Uint*)(esp-=4) = (Uint)newThread;     // Thread ID
 592
 593         newThread->SavedState.ESP = esp;
 594         newThread->SavedState.EIP = (Uint)&NewTaskHeader;
 595         newThread->SavedState.SSE = NULL;
 596         Log("New (KThread) %p, esp = %p\n", newThread->SavedState.EIP, newThread->SavedState.ESP);
 597
 598 //      MAGIC_BREAK();
 599         Threads_AddActive(newThread);
 600
 601         return newThread->TID;
 602 }
 603
 604 /**
 605  * \fn int Proc_Clone(Uint *Err, Uint Flags)
 606  * \brief Clone the current process
 607  */
 608 int Proc_Clone(Uint Flags)
 609 {
 610         tThread *newThread;
 611         tThread *cur = Proc_GetCurThread();
 612         Uint    eip;
 613
 614         // Sanity, please
 615         if( !(Flags & CLONE_VM) ) {
 616                 Log_Error("Proc", "Proc_Clone: Don't leave CLONE_VM unset, use Proc_NewKThread instead");
 617                 return -1;
 618         }
 619
 620         // New thread
 621         newThread = Threads_CloneTCB(Flags);
 622         if(!newThread)  return -1;
 623
 624         newThread->KernelStack = cur->KernelStack;
 625
 626         // Clone state
 627         eip = Proc_CloneInt(&newThread->SavedState.ESP, &newThread->MemState.CR3);
 628         if( eip == 0 ) {
 629                 // ACK the interrupt
 630                 return 0;
 631         }
 632         newThread->SavedState.EIP = eip;
 633         newThread->SavedState.SSE = NULL;
 634         newThread->SavedState.bSSEModified = 0;
 635
 636         // Check for errors
 637         if( newThread->MemState.CR3 == 0 ) {
 638                 Log_Error("Proc", "Proc_Clone: MM_Clone failed");
 639                 Threads_Delete(newThread);
 640                 return -1;
 641         }
 642
 643         // Add the new thread to the run queue
 644         Threads_AddActive(newThread);
 645         return newThread->TID;
 646 }
 647
 648 /**
 649  * \fn int Proc_SpawnWorker(void)
 650  * \brief Spawns a new worker thread
 651  */
 652 int Proc_SpawnWorker(void (*Fcn)(void*), void *Data)
 653 {
 654         tThread *new;
 655         Uint    stack_contents[4];
 656
 657         // Create new thread
 658         new = Threads_CloneThreadZero();
 659         if(!new) {
 660                 Warning("Proc_SpawnWorker - Out of heap space!\n");
 661                 return -1;
 662         }
 663
 664         // Create the stack contents
 665         stack_contents[3] = (Uint)Data;
 666         stack_contents[2] = 1;
 667         stack_contents[1] = (Uint)Fcn;
 668         stack_contents[0] = (Uint)new;
 669
 670         // Create a new worker stack (in PID0's address space)
 671         new->KernelStack = MM_NewWorkerStack(stack_contents, sizeof(stack_contents));
 672
 673         // Save core machine state
 674         new->SavedState.ESP = new->KernelStack - sizeof(stack_contents);
 675         new->SavedState.EIP = (Uint)NewTaskHeader;
 676         new->SavedState.SSE = NULL;
 677         new->SavedState.bSSEModified = 0;
 678
 679         // Mark as active
 680         new->Status = THREAD_STAT_PREINIT;
 681         Threads_AddActive( new );
 682
 683         return new->TID;
 684 }
 685
 686 /**
 687  * \fn Uint Proc_MakeUserStack(void)
 688  * \brief Creates a new user stack
 689  */
 690 Uint Proc_MakeUserStack(void)
 691 {
 692          int    i;
 693         Uint    base = USER_STACK_TOP - USER_STACK_SZ;
 694
 695         // Check Prospective Space
 696         for( i = USER_STACK_SZ >> 12; i--; )
 697                 if( MM_GetPhysAddr( base + (i<<12) ) != 0 )
 698                         break;
 699
 700         if(i != -1)     return 0;
 701
 702         // Allocate Stack - Allocate incrementally to clean up MM_Dump output
 703         for( i = 0; i < USER_STACK_SZ/0x1000; i++ )
 704         {
 705                 if( !MM_Allocate( base + (i<<12) ) )
 706                 {
 707                         Warning("OOM: Proc_MakeUserStack");
 708                         return 0;
 709                 }
 710         }
 711
 712         return base + USER_STACK_SZ;
 713 }
 714
 715 void Proc_StartUser(Uint Entrypoint, Uint Base, int ArgC, char **ArgV, int DataSize)
 716 {
 717         Uint    *stack;
 718          int    i;
 719         char    **envp = NULL;
 720         Uint16  ss, cs;
 721
 722         // Copy data to the user stack and free original buffer
 723         stack = (void*)Proc_MakeUserStack();
 724         stack -= DataSize/sizeof(*stack);
 725         memcpy( stack, ArgV, DataSize );
 726         free(ArgV);
 727
 728         // Adjust Arguments and environment
 729         if( DataSize )
 730         {
 731                 Uint delta = (Uint)stack - (Uint)ArgV;
 732                 ArgV = (char**)stack;
 733                 for( i = 0; ArgV[i]; i++ )      ArgV[i] += delta;
 734                 envp = &ArgV[i+1];
 735                 for( i = 0; envp[i]; i++ )      envp[i] += delta;
 736         }
 737
 738         // User Mode Segments
 739         ss = 0x23;      cs = 0x1B;
 740
 741         // Arguments
 742         *--stack = (Uint)envp;
 743         *--stack = (Uint)ArgV;
 744         *--stack = (Uint)ArgC;
 745         *--stack = Base;
 746
 747         Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
 748 }
 749
 750 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
 751 {
 752         Uint    *stack = (void*)Stack;
 753         *--stack = SS;          //Stack Segment
 754         *--stack = Stack;       //Stack Pointer
 755         *--stack = Flags;       //EFLAGS (Resvd (0x2) and IF (0x20))
 756         *--stack = CS;          //Code Segment
 757         *--stack = IP;  //EIP
 758         //PUSHAD
 759         *--stack = 0xAAAAAAAA;  // eax
 760         *--stack = 0xCCCCCCCC;  // ecx
 761         *--stack = 0xDDDDDDDD;  // edx
 762         *--stack = 0xBBBBBBBB;  // ebx
 763         *--stack = 0xD1D1D1D1;  // edi
 764         *--stack = 0x54545454;  // esp - NOT POPED
 765         *--stack = 0x51515151;  // esi
 766         *--stack = 0xB4B4B4B4;  // ebp
 767         //Individual PUSHs
 768         *--stack = SS;  // ds
 769         *--stack = SS;  // es
 770         *--stack = SS;  // fs
 771         *--stack = SS;  // gs
 772
 773         __asm__ __volatile__ (
 774         "mov %%eax,%%esp;\n\t"  // Set stack pointer
 775         "pop %%gs;\n\t"
 776         "pop %%fs;\n\t"
 777         "pop %%es;\n\t"
 778         "pop %%ds;\n\t"
 779         "popa;\n\t"
 780         "iret;\n\t" : : "a" (stack));
 781         for(;;);
 782 }
 783
 784 /**
 785  * \fn int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 786  * \brief Demotes a process to a lower permission level
 787  * \param Err   Pointer to user's errno
 788  * \param Dest  New Permission Level
 789  * \param Regs  Pointer to user's register structure
 790  */
 791 int Proc_Demote(Uint *Err, int Dest, tRegs *Regs)
 792 {
 793          int    cpl = Regs->cs & 3;
 794         // Sanity Check
 795         if(Dest > 3 || Dest < 0) {
 796                 *Err = -EINVAL;
 797                 return -1;
 798         }
 799
 800         // Permission Check
 801         if(cpl > Dest) {
 802                 *Err = -EACCES;
 803                 return -1;
 804         }
 805
 806         // Change the Segment Registers
 807         Regs->cs = (((Dest+1)<<4) | Dest) - 8;
 808         Regs->ss = ((Dest+1)<<4) | Dest;
 809         // Check if the GP Segs are GDT, then change them
 810         if(!(Regs->ds & 4))     Regs->ds = ((Dest+1)<<4) | Dest;
 811         if(!(Regs->es & 4))     Regs->es = ((Dest+1)<<4) | Dest;
 812         if(!(Regs->fs & 4))     Regs->fs = ((Dest+1)<<4) | Dest;
 813         if(!(Regs->gs & 4))     Regs->gs = ((Dest+1)<<4) | Dest;
 814
 815         return 0;
 816 }
 817
 818 /**
 819  * \brief Calls a signal handler in user mode
 820  * \note Used for signals
 821  */
 822 void Proc_CallFaultHandler(tThread *Thread)
 823 {
 824         // Rewinds the stack and calls the user function
 825         // Never returns
 826         Proc_ReturnToUser( Thread->FaultHandler, Thread->CurFaultNum, Thread->KernelStack );
 827         for(;;);
 828 }
 829
 830 void Proc_DumpThreadCPUState(tThread *Thread)
 831 {
 832         if( Thread->CurCPU > -1 )
 833         {
 834                  int    maxBacktraceDistance = 6;
 835                 tRegs   *regs = NULL;
 836                 Uint32  *stack;
 837
 838                 if( Thread->CurCPU != GetCPUNum() ) {
 839                         Log("  Currently running");
 840                         return ;
 841                 }
 842
 843                 // Backtrace to find the IRQ entrypoint
 844                 // - This will usually only be called by an IRQ, so this should
 845                 //   work
 846                 __asm__ __volatile__ ("mov %%ebp, %0" : "=r" (stack));
 847                 while( maxBacktraceDistance -- )
 848                 {
 849                         // [ebp] = oldEbp
 850                         // [ebp+4] = retaddr
 851
 852                         if( stack[1] == (tVAddr)&IRQCommon_handled ) {
 853                                 regs = (void*)stack[2];
 854                                 break;
 855                         }
 856
 857                         stack = (void*)stack[0];
 858                 }
 859
 860                 if( !regs ) {
 861                         Log("  Unable to find IRQ Entry");
 862                         return ;
 863                 }
 864
 865                 Log("  at %04x:%08x", regs->cs, regs->eip);
 866                 return ;
 867         }
 868
 869         tVAddr  diffFromScheduler = Thread->SavedState.EIP - (tVAddr)SwitchTasks;
 870         tVAddr  diffFromClone = Thread->SavedState.EIP - (tVAddr)Proc_CloneInt;
 871         tVAddr  diffFromSpawn = Thread->SavedState.EIP - (tVAddr)NewTaskHeader;
 872
 873         if( diffFromClone > 0 && diffFromClone < 40 )   // When I last checked, .newTask was at .+27
 874         {
 875                 Log("  Creating process");
 876                 return ;
 877         }
 878
 879         if( diffFromSpawn == 0 )
 880         {
 881                 Log("  Creating thread");
 882                 return ;
 883         }
 884
 885         if( diffFromScheduler > 0 && diffFromScheduler < 128 )  // When I last checked, GetEIP was at .+0x30
 886         {
 887                 // Scheduled out
 888                 Log("  At %04x:%08x", Thread->SavedState.UserCS, Thread->SavedState.UserEIP);
 889                 return ;
 890         }
 891
 892         Log("  Just created (unknown %p)", Thread->SavedState.EIP);
 893 }
 894
 895 void Proc_Reschedule(void)
 896 {
 897         tThread *nextthread, *curthread;
 898          int    cpu = GetCPUNum();
 899
 900         // TODO: Wait for the lock?
 901         if(IS_LOCKED(&glThreadListLock))        return;
 902
 903         curthread = Proc_GetCurThread();
 904
 905         nextthread = Threads_GetNextToRun(cpu, curthread);
 906
 907         if(!nextthread)
 908                 nextthread = gaCPUs[cpu].IdleThread;
 909         if(!nextthread || nextthread == curthread)
 910                 return ;
 911
 912         #if DEBUG_TRACE_SWITCH
 913         LogF("\nSwitching to task %i, CR3 = 0x%x, EIP = %p, ESP = %p\n",
 914                 nextthread->TID,
 915                 nextthread->MemState.CR3,
 916                 nextthread->SavedState.EIP,
 917                 nextthread->SavedState.ESP
 918                 );
 919         #endif
 920
 921         // Update CPU state
 922         gaCPUs[cpu].Current = nextthread;
 923         gTSSs[cpu].ESP0 = nextthread->KernelStack-4;
 924         __asm__ __volatile__("mov %0, %%db0\n\t" : : "r"(nextthread) );
 925
 926         // Save FPU/MMX/XMM/SSE state
 927         if( curthread->SavedState.SSE )
 928         {
 929                 Proc_SaveSSE( ((Uint)curthread->SavedState.SSE + 0xF) & ~0xF );
 930                 curthread->SavedState.bSSEModified = 0;
 931                 Proc_DisableSSE();
 932         }
 933
 934         SwitchTasks(
 935                 nextthread->SavedState.ESP, &curthread->SavedState.ESP,
 936                 nextthread->SavedState.EIP, &curthread->SavedState.EIP,
 937                 nextthread->MemState.CR3
 938                 );
 939
 940         return ;
 941 }
 942
 943 /**
 944  * \fn void Proc_Scheduler(int CPU)
 945  * \brief Swap current thread and clears dead threads
 946  */
 947 void Proc_Scheduler(int CPU)
 948 {
 949         tThread *thread;
 950
 951         // If the spinlock is set, let it complete
 952         if(IS_LOCKED(&glThreadListLock))        return;
 953
 954         // Get current thread
 955         thread = gaCPUs[CPU].Current;
 956
 957         if( thread )
 958         {
 959                 tRegs   *regs;
 960                 Uint    ebp;
 961                 // Reduce remaining quantum and continue timeslice if non-zero
 962                 if( thread->Remaining-- )
 963                         return;
 964                 // Reset quantum for next call
 965                 thread->Remaining = thread->Quantum;
 966
 967                 // TODO: Make this more stable somehow
 968                 __asm__ __volatile__("mov %%ebp, %0" : "=r" (ebp));
 969                 regs = (tRegs*)(ebp+(2+2)*4);   // EBP,Ret + CPU,CurThread
 970                 thread->SavedState.UserCS = regs->cs;
 971                 thread->SavedState.UserEIP = regs->eip;
 972
 973                 if(thread->bInstrTrace) {
 974                         regs->eflags |= 0x100;  // Set TF
 975                         Log("%p De-scheduled", thread);
 976                 }
 977                 else
 978                         regs->eflags &= ~0x100; // Clear TF
 979         }
 980
 981 #if 0
 982         // TODO: Ack timer?
 983         #if USE_MP
 984         if( GetCPUNum() )
 985                 gpMP_LocalAPIC->EOI.Val = 0;
 986         else
 987         #endif
 988                 outb(0x20, 0x20);
 989         __asm__ __volatile__ ("sti");
 990         Proc_Reschedule();
 991 #endif
 992 }
 993
 994 // === EXPORTS ===
 995 EXPORT(Proc_SpawnWorker);