108 lines
2.2 KiB
C
108 lines
2.2 KiB
C
/*
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* tasking-multi.c
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*
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* Created on: Sep 8, 2011
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* Author: Tiberiu
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*/
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#include <tasking.h>
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#include <memory-add.h>
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#include <stdio.h>
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Task* TaskList;
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Task* CurrentTask;
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uint32 NextPid = 1;
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void TaskSwitch (_RegsStack32* regs)
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{
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MagicBreakpoint();
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if (!TaskList) return;
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uint32 eip = TaskReadEip();
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if (eip == 0xABCDEF) return;
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// Save context
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asm volatile ("mov %%esp, %0" : "=r"(CurrentTask->Esp));
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asm volatile ("mov %%ebp, %0" : "=r"(CurrentTask->Ebp));
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CurrentTask->Eip = eip;
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// Next task
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CurrentTask = (!CurrentTask->Next) ? TaskList : CurrentTask->Next ;
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// Switch context
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PagingSwitchDirectory(CurrentTask->Pd);
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// Prepare for jump
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asm volatile (""
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"mov %0, %%ebp; "
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"mov %1, %%esp; "
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"mov %2, %%ecx; "
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"mov $0xABCDEF, %%eax; "
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"jmp *%%ecx; "
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: : "r"(CurrentTask->Ebp), "r"(CurrentTask->Esp), "r"(CurrentTask->Eip)
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: "eax", "ecx");
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}
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// Fallback for new tasks
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void TaskEnd ()
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{
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// Find parent of current task
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if (CurrentTask->Pid == TaskList->Pid) TaskList = TaskList->Next;
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else {
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Task* t = TaskList;
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while (t->Next && t->Next->Pid != CurrentTask->Pid) t = t->Next;
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t->Next = CurrentTask->Next;
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}
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// Free allocated space
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kfree((void*)CurrentTask->StackLowerBase);
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kfree(CurrentTask);
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// Wait for next task
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for (;;) ;
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}
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void TaskCreate (void (*func)())
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{
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// Create a new task
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Task* t = kmalloc(sizeof(Task));
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// Set up data
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t->StackLowerBase = (uint32) kmalloc(0x1000); // Allocate some space for new stack
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t->StackUpperBase = t->StackLowerBase + 0x1000;
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t->Next = NULL;
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t->Pd = KernelDirectory;
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t->Pid = NextPid++;
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// Set up stack
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/*memset(&t->Regs, 0, sizeof(_RegsStack32));
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t->Regs.ebp = t->StackUpperBase;
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t->Regs.esp = (t->StackUpperBase - 0x4 - sizeof(_RegsStack32));
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t->Regs.useresp = t->StackUpperBase - 0x4;
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t->Regs.eip = (uint32) func;
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*(uint32 *) (t->Regs.esp) = (uint32) TaskEnd; // Fallback function
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t->Initialized = 0;
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// Read eflags
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asm volatile ("pushf; pop %0" : "=r"(t->Regs.eflags));*/
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// Add the task to the list
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Task* last = TaskList;
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while (last && last->Next) last = last->Next;
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if (last) last->Next = t;
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}
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void TaskInitialize()
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{
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Task* t = kmalloc(sizeof(Task));
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t->Pid = NextPid++;
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t->Pd = KernelDirectory;
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t->Next = NULL;
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TaskList = CurrentTask = t;
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}
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