--- /dev/null
+/*
+ * Acess2 VM8086 Driver
+ * - By John Hodge (thePowersGang)
+ */
+#include <acess.h>
+#include <vm8086.h>
+#include <modules.h>
+
+// === CONSTANTS ===
+#define VM8086_MAGIC_CS 0xFFFF
+#define VM8086_MAGIC_IP 0x0010
+#define VM8086_STACK_SEG 0x9F00
+#define VM8086_STACK_OFS 0x0AFE
+enum eVM8086_Opcodes
+{
+ VM8086_OP_PUSHF = 0x9C,
+ VM8086_OP_POPF = 0x9D,
+ VM8086_OP_INT_I = 0xCD,
+ VM8086_OP_IRET = 0xCF
+};
+#define VM8086_PAGES_PER_INST 4
+
+// === IMPORTS ===
+ int Proc_Clone(Uint *Err, Uint Flags);
+
+// === TYPES ===
+struct sVM8086_InternalData
+{
+ struct {
+ Uint32 Bitmap; // 32 sections = 128 byte blocks
+ tVAddr VirtBase;
+ tPAddr PhysAddr;
+ } AllocatedPages[VM8086_PAGES_PER_INST];
+};
+
+// === PROTOTYPES ===
+ int VM8086_Install(char **Arguments);
+void VM8086_GPF(tRegs *Regs);
+tVM8086 *VM8086_Init(void);
+
+// === GLOBALS ===
+MODULE_DEFINE(0, 0x100, VM8086, VM8086_Install, NULL, NULL);
+tSpinlock glVM8086_Process;
+tPID gVM8086_WorkerPID;
+tTID gVM8086_CallingThread;
+tVM8086 * volatile gpVM8086_State;
+
+// === FUNCTIONS ===
+int VM8086_Install(char **Arguments)
+{
+ tPID pid;
+
+ // Create BIOS Call process
+ pid = Proc_Clone(NULL, CLONE_VM);
+ if(pid == -1)
+ {
+ Log_Error("VM8086", "Unable to clone kernel into VM8086 worker");
+ return MODULE_ERR_MISC;
+ }
+ if(pid == 0)
+ {
+ Uint *stacksetup; // Initialising Stack
+ Uint16 *rmstack; // Real Mode Stack
+ int i;
+
+ // Set Image Name
+ Threads_SetName("VM8086");
+
+ // Map ROM Area
+ for(i=0xA0;i<0x100;i++) {
+ MM_Map( i * 0x1000, i * 0x1000 );
+ MM_SetFlags( i * 0x1000, MM_PFLAG_RO, MM_PFLAG_RO ); // Set Read Only
+ }
+ MM_Map( 0, 0 ); // IVT / BDA
+ for(i=0x70;i<0x80;i++) {
+ MM_Map( i * 0x1000, i * 0x1000 ); MM_DerefPhys( i * 0x1000 );
+ }
+ MM_Map( 0x9F000, 0x9F000 ); // Stack / EBDA
+ MM_Allocate( 0x100000 ); // System Stack / Stub
+
+ *(Uint8*)(0x100000) = VM8086_OP_IRET;
+ *(Uint8*)(0x100001) = 0x07; // POP ES
+ *(Uint8*)(0x100002) = 0x1F; // POP DS
+ *(Uint8*)(0x100003) = 0xCB; // RET FAR
+
+ rmstack = (Uint16*)(VM8086_STACK_SEG*16 + VM8086_STACK_OFS);
+ *rmstack-- = 0xFFFF; //CS
+ *rmstack-- = 0x0010; //IP
+
+ // Setup Stack
+ stacksetup = (Uint*)0x101000;
+ *--stacksetup = VM8086_STACK_SEG; // GS
+ *--stacksetup = VM8086_STACK_SEG; // FS
+ *--stacksetup = VM8086_STACK_SEG; // DS
+ *--stacksetup = VM8086_STACK_SEG; // ES
+ *--stacksetup = VM8086_STACK_SEG; // SS
+ *--stacksetup = VM8086_STACK_OFS-2; // SP
+ *--stacksetup = 0x20202; // FLAGS
+ *--stacksetup = 0xFFFF; // CS
+ *--stacksetup = 0x10; // IP
+ *--stacksetup = 0xAAAA; // AX
+ *--stacksetup = 0xCCCC; // CX
+ *--stacksetup = 0xDDDD; // DX
+ *--stacksetup = 0xBBBB; // BX
+ *--stacksetup = 0x5454; // SP
+ *--stacksetup = 0xB4B4; // BP
+ *--stacksetup = 0x5151; // SI
+ *--stacksetup = 0xD1D1; // DI
+ *--stacksetup = 0x20|3; // DS - Kernel
+ *--stacksetup = 0x20|3; // ES - Kernel
+ *--stacksetup = 0x20|3; // FS
+ *--stacksetup = 0x20|3; // GS
+ __asm__ __volatile__ (
+ "mov %%eax,%%esp;\n\t" // Set stack pointer
+ "pop %%gs;\n\t"
+ "pop %%fs;\n\t"
+ "pop %%es;\n\t"
+ "pop %%ds;\n\t"
+ "popa;\n\t"
+ "iret;\n\t" : : "a" (stacksetup));
+ for(;;); // Shouldn't be reached
+ }
+
+ gVM8086_WorkerPID = pid;
+ Log_Log("VM8086", "gVM8086_WorkerPID = %i", pid);
+ Threads_Yield(); // Yield to allow the child to initialise
+
+ return MODULE_ERR_OK;
+}
+
+void VM8086_GPF(tRegs *Regs)
+{
+ Uint8 opcode;
+
+ //Log_Log("VM8086", "GPF - %04x:%04x", Regs->cs, Regs->eip);
+
+ if(Regs->eip == VM8086_MAGIC_IP && Regs->cs == VM8086_MAGIC_CS
+ && Threads_GetPID() == gVM8086_WorkerPID)
+ {
+ if( gpVM8086_State ) {
+ gpVM8086_State->AX = Regs->eax; gpVM8086_State->CX = Regs->ecx;
+ gpVM8086_State->DX = Regs->edx; gpVM8086_State->BX = Regs->ebx;
+ gpVM8086_State->BP = Regs->ebp;
+ gpVM8086_State->SI = Regs->esi; gpVM8086_State->DI = Regs->edi;
+ gpVM8086_State->DS = Regs->ds; gpVM8086_State->ES = Regs->es;
+ gpVM8086_State = NULL;
+ Threads_WakeTID(gVM8086_CallingThread);
+ }
+
+ //Log_Log("VM8086", "Waiting for something to do");
+ __asm__ __volatile__ ("sti");
+ // Wait for a new task
+ while(!gpVM8086_State) {
+ Threads_Sleep();
+ //Log_Log("VM8086", "gpVM8086_State = %p", gpVM8086_State);
+ }
+
+ //Log_Log("VM8086", "We have a task");
+ Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_CS;
+ Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = VM8086_MAGIC_IP;
+ Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->CS;
+ Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->IP;
+ Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->DS;
+ Regs->esp -= 2; *(Uint16*)( (Regs->ss<<4) + (Regs->esp&0xFFFF) ) = gpVM8086_State->ES;
+
+ // Set Registers
+ Regs->eip = 0x11; Regs->cs = 0xFFFF;
+ Regs->eax = gpVM8086_State->AX; Regs->ecx = gpVM8086_State->CX;
+ Regs->edx = gpVM8086_State->DX; Regs->ebx = gpVM8086_State->BX;
+ Regs->esi = gpVM8086_State->SI; Regs->edi = gpVM8086_State->DI;
+ Regs->ebp = gpVM8086_State->BP;
+ Regs->ds = 0x23; Regs->es = 0x23;
+ Regs->fs = 0x23; Regs->gs = 0x23;
+ return ;
+ }
+
+ opcode = *(Uint8*)( KERNEL_BASE + (Regs->cs*16) + (Regs->eip) );
+ Regs->eip ++;
+ switch(opcode)
+ {
+ case VM8086_OP_PUSHF: //PUSHF
+ Regs->esp -= 2;
+ *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eflags & 0xFFFF;
+ #if TRACE_EMU
+ Log_Debug("VM8086", "Emulated PUSHF");
+ #endif
+ break;
+ case VM8086_OP_POPF: //POPF
+ Regs->eflags &= 0xFFFF0002;
+ Regs->eflags |= *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) & 0xFFFD; // Changing IF is not allowed
+ Regs->esp += 2;
+ #if TRACE_EMU
+ Log_Debug("VM8086", "Emulated POPF");
+ #endif
+ break;
+
+ case VM8086_OP_INT_I: //INT imm8
+ {
+ int id;
+ id = *(Uint8*)( Regs->cs*16 +(Regs->eip&0xFFFF));
+ Regs->eip ++;
+
+ Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->cs;
+ Regs->esp -= 2; *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ) = Regs->eip;
+
+ Regs->cs = *(Uint16*)(4*id + 2);
+ Regs->eip = *(Uint16*)(4*id);
+ #if TRACE_EMU
+ Log_Debug("VM8086", "Emulated INT 0x%x", id);
+ #endif
+ }
+ break;
+
+ case 0xCF: //IRET
+ Regs->eip = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
+ Regs->cs = *(Uint16*)( Regs->ss*16 + (Regs->esp&0xFFFF) ); Regs->esp += 2;
+ #if TRACE_EMU
+ Log_Debug("VM8086", "IRET to %04x:%04x", Regs->cs, Regs->eip);
+ #endif
+ break;
+
+ default:
+ Log_Error("VM8086", "Error - Unknown opcode %02x caused a GPF at %04x:%04x",
+ opcode, Regs->cs, Regs->eip);
+ // Force an end to the call
+ Regs->cs = VM8086_MAGIC_CS;
+ Regs->eip = VM8086_MAGIC_IP;
+ break;
+ }
+}
+
+/**
+ * \brief Create an instance of the VM8086 Emulator
+ */
+tVM8086 *VM8086_Init(void)
+{
+ tVM8086 *ret;
+ ret = calloc( 1, sizeof(tVM8086) + sizeof(struct sVM8086_InternalData) );
+ ret->Internal = (void*)((tVAddr)ret + sizeof(tVM8086));
+ return ret;
+}
+
+void VM8086_Free(tVM8086 *State)
+{
+ int i;
+ for( i = VM8086_PAGES_PER_INST; i --; )
+ MM_UnmapHWPages( State->Internal->AllocatedPages[i].VirtBase, 1);
+ free(State);
+}
+
+void *VM8086_Allocate(tVM8086 *State, int Size, Uint16 *Segment, Uint16 *Offset)
+{
+ int i, j, base = 0;
+ int nBlocks, rem;
+ Uint32 bmp;
+
+ Size = (Size + 127) & ~127;
+ nBlocks = Size >> 7;
+
+ if(Size > 4096) return NULL;
+
+ for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
+ {
+ if( State->Internal->AllocatedPages[i].VirtBase == 0 ) continue;
+ bmp = State->Internal->AllocatedPages[i].Bitmap;
+ rem = nBlocks;
+ base = 0;
+ // Scan the bitmap for a free block
+ for( j = 0; j < 32-nBlocks; j++ ) {
+ if( bmp & (1 << j) ) {
+ base = 0;
+ rem = nBlocks;
+ }
+ else {
+ rem --;
+ if(rem == 0) // Goodie, there's a gap
+ {
+ for( j = 0; j < nBlocks; j++ )
+ State->Internal->AllocatedPages[i].Bitmap |= 1 << (base + j);
+ *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16 + base * 8;
+ *Offset = 0;
+ return (void*)( State->Internal->AllocatedPages[i].VirtBase + base * 128 );
+ }
+ }
+ }
+ }
+
+ // No pages with free space?, allocate a new one
+ for( i = 0; i < VM8086_PAGES_PER_INST; i++ )
+ {
+ if( State->Internal->AllocatedPages[i].VirtBase == 0 ) break;
+ }
+ // Darn, we can't allocate any more
+ if( i == VM8086_PAGES_PER_INST ) {
+ Log_Warning("VM8086", "Out of pages in %p", State);
+ return NULL;
+ }
+
+ State->Internal->AllocatedPages[i].VirtBase = MM_AllocDMA(
+ 1, 20, &State->Internal->AllocatedPages[i].PhysAddr);
+ State->Internal->AllocatedPages[i].Bitmap = 0;
+
+ for( j = 0; j < nBlocks; j++ )
+ State->Internal->AllocatedPages[i].Bitmap |= 1 << j;
+ *Segment = State->Internal->AllocatedPages[i].PhysAddr / 16;
+ *Offset = 0;
+ return (void*) State->Internal->AllocatedPages[i].VirtBase;
+}
+
+void *VM8086_GetPointer(tVM8086 *State, Uint16 Segment, Uint16 Offset)
+{
+ return (void*)( KERNEL_BASE + Segment*16 + Offset );
+}
+
+void VM8086_Int(tVM8086 *State, Uint8 Interrupt)
+{
+ State->IP = *(Uint16*)(KERNEL_BASE+4*Interrupt);
+ State->CS = *(Uint16*)(KERNEL_BASE+4*Interrupt+2);
+
+ LOCK( &glVM8086_Process );
+
+ gpVM8086_State = State;
+ gVM8086_CallingThread = Threads_GetTID();
+ Threads_WakeTID( gVM8086_WorkerPID );
+ while( gpVM8086_State != NULL )
+ Threads_Sleep();
+
+ RELEASE( &glVM8086_Process );
+}
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