/*****************************************************************************/ /* */ /* paravirt.c */ /* */ /* Paravirtualization for the sim65 6502 simulator */ /* */ /* */ /* */ /* (C) 2013-2013 Ullrich von Bassewitz */ /* Roemerstrasse 52 */ /* D-70794 Filderstadt */ /* EMail: uz@cc65.org */ /* */ /* */ /* This software is provided 'as-is', without any expressed or implied */ /* warranty. In no event will the authors be held liable for any damages */ /* arising from the use of this software. */ /* */ /* Permission is granted to anyone to use this software for any purpose, */ /* including commercial applications, and to alter it and redistribute it */ /* freely, subject to the following restrictions: */ /* */ /* 1. The origin of this software must not be misrepresented; you must not */ /* claim that you wrote the original software. If you use this software */ /* in a product, an acknowledgment in the product documentation would be */ /* appreciated but is not required. */ /* 2. Altered source versions must be plainly marked as such, and must not */ /* be misrepresented as being the original software. */ /* 3. This notice may not be removed or altered from any source */ /* distribution. */ /* */ /*****************************************************************************/ #include #include #include #include #if defined(_WIN32) # define O_INITIAL O_BINARY #else # define O_INITIAL 0 #endif #if defined(_MSC_VER) /* Microsoft compiler */ # include #else /* Anyone else */ # include #endif #ifndef S_IREAD # define S_IREAD S_IRUSR #endif #ifndef S_IWRITE # define S_IWRITE S_IWUSR #endif /* common */ #include "cmdline.h" #include "print.h" #include "xmalloc.h" /* sim65 */ #include "6502.h" #include "error.h" #include "memory.h" #include "paravirt.h" /*****************************************************************************/ /* Data */ /*****************************************************************************/ typedef void (*PVFunc) (CPURegs* Regs); static unsigned ArgStart; static unsigned char SPAddr; /*****************************************************************************/ /* Code */ /*****************************************************************************/ static unsigned GetAX (CPURegs* Regs) { return Regs->AC + (Regs->XR << 8); } static void SetAX (CPURegs* Regs, unsigned Val) { Regs->AC = Val & 0xFF; Val >>= 8; Regs->XR = Val; } static unsigned char Pop (CPURegs* Regs) { return MemReadByte (0x0100 + (++Regs->SP & 0xFF)); } static unsigned PopParam (unsigned char Incr) { unsigned SP = MemReadZPWord (SPAddr); unsigned Val = MemReadWord (SP); MemWriteWord (SPAddr, SP + Incr); return Val; } static void PVExit (CPURegs* Regs) { Print (stderr, 1, "PVExit ($%02X)\n", Regs->AC); SimExit (Regs->AC); /* Error code in range 0-255. */ } static void PVArgs (CPURegs* Regs) { unsigned ArgC = ArgCount - ArgStart; unsigned ArgV = GetAX (Regs); unsigned SP = MemReadZPWord (SPAddr); unsigned Args = SP - (ArgC + 1) * 2; Print (stderr, 2, "PVArgs ($%04X)\n", ArgV); MemWriteWord (ArgV, Args); SP = Args; while (ArgStart < ArgCount) { unsigned I = 0; const char* Arg = ArgVec[ArgStart++]; SP -= strlen (Arg) + 1; do { MemWriteByte (SP + I, Arg[I]); } while (Arg[I++]); MemWriteWord (Args, SP); Args += 2; } MemWriteWord (Args, SPAddr); MemWriteWord (SPAddr, SP); SetAX (Regs, ArgC); } static void PVOpen (CPURegs* Regs) { char Path[PVOPEN_PATH_SIZE]; int OFlag = O_INITIAL; int OMode = 0; unsigned RetVal, I = 0; unsigned Mode = PopParam (Regs->YR - 4); unsigned Flags = PopParam (2); unsigned Name = PopParam (2); if (Regs->YR - 4 < 2) { /* If the caller didn't supply the mode ** argument, use a reasonable default. */ Mode = 0x01 | 0x02; } do { if (!(Path[I] = MemReadByte ((Name + I) & 0xFFFF))) { break; } ++I; if (I >= PVOPEN_PATH_SIZE) { Error("PVOpen path too long at address $%04X",Name); } } while (1); Print (stderr, 2, "PVOpen (\"%s\", $%04X)\n", Path, Flags); switch (Flags & 0x03) { case 0x01: OFlag |= O_RDONLY; break; case 0x02: OFlag |= O_WRONLY; break; case 0x03: OFlag |= O_RDWR; break; } if (Flags & 0x10) { OFlag |= O_CREAT; } if (Flags & 0x20) { OFlag |= O_TRUNC; } if (Flags & 0x40) { OFlag |= O_APPEND; } if (Flags & 0x80) { OFlag |= O_EXCL; } if (Mode & 0x01) { OMode |= S_IREAD; } if (Mode & 0x02) { OMode |= S_IWRITE; } RetVal = open (Path, OFlag, OMode); SetAX (Regs, RetVal); } static void PVClose (CPURegs* Regs) { unsigned RetVal; unsigned FD = GetAX (Regs); Print (stderr, 2, "PVClose ($%04X)\n", FD); if (FD != 0xFFFF) { RetVal = close (FD); } else { /* test/val/constexpr.c "abuses" close, expecting close(-1) to return -1. ** This behaviour is not the same on all target platforms. ** MSVC's close treats it as a fatal error instead and terminates. */ RetVal = 0xFFFF; } SetAX (Regs, RetVal); } static void PVRead (CPURegs* Regs) { unsigned char* Data; unsigned RetVal, I = 0; unsigned Count = GetAX (Regs); unsigned Buf = PopParam (2); unsigned FD = PopParam (2); Print (stderr, 2, "PVRead ($%04X, $%04X, $%04X)\n", FD, Buf, Count); Data = xmalloc (Count); RetVal = read (FD, Data, Count); if (RetVal != (unsigned) -1) { while (I < RetVal) { MemWriteByte (Buf++, Data[I++]); } } xfree (Data); SetAX (Regs, RetVal); } static void PVWrite (CPURegs* Regs) { unsigned char* Data; unsigned RetVal, I = 0; unsigned Count = GetAX (Regs); unsigned Buf = PopParam (2); unsigned FD = PopParam (2); Print (stderr, 2, "PVWrite ($%04X, $%04X, $%04X)\n", FD, Buf, Count); Data = xmalloc (Count); while (I < Count) { Data[I++] = MemReadByte (Buf++); } RetVal = write (FD, Data, Count); xfree (Data); SetAX (Regs, RetVal); } static const PVFunc Hooks[] = { PVOpen, PVClose, PVRead, PVWrite, PVArgs, PVExit, }; void ParaVirtInit (unsigned aArgStart, unsigned char aSPAddr) /* Initialize the paravirtualization subsystem */ { ArgStart = aArgStart; SPAddr = aSPAddr; }; void ParaVirtHooks (CPURegs* Regs) /* Potentially execute paravirtualization hooks */ { unsigned lo; /* Check for paravirtualization address range */ if (Regs->PC < PARAVIRT_BASE || Regs->PC >= PARAVIRT_BASE + sizeof (Hooks) / sizeof (Hooks[0])) { return; } /* Call paravirtualization hook */ Hooks[Regs->PC - PARAVIRT_BASE] (Regs); /* Simulate RTS */ lo = Pop (Regs); Regs->PC = lo + (Pop (Regs) << 8) + 1; }