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