v86_x86emu.c

   1 #include <stdarg.h>
   2 #include <string.h>
   3 #include <x86emu.h>
   4 #include "v86.h"
   5 #include "v86_x86emu.h"
   6
   7 u32 stack;
   8 u32 halt;
   9
  10 __BUILDIO(b,b,u8);
  11 __BUILDIO(w,w,u16);
  12 __BUILDIO(l,,u32);
  13
  14 void printk(const char *fmt, ...)
  15 {
  16         va_list argptr;
  17         va_start(argptr, fmt);
  18         vsyslog(LOG_INFO, fmt, argptr);
  19         va_end(argptr);
  20 }
  21
  22 void pushw(u16 val)
  23 {
  24         X86_ESP -= 2;
  25         v_wrw(((u32) X86_SS << 4) + X86_SP, val);
  26 }
  27
  28 static void x86emu_do_int(int num)
  29 {
  30         u32 eflags;
  31
  32         eflags = X86_EFLAGS;
  33
  34         /* Return address and flags */
  35         pushw(eflags);
  36         pushw(X86_CS);
  37         pushw(X86_IP);
  38
  39         X86_EFLAGS = X86_EFLAGS & ~(X86_VIF_MASK | X86_TF_MASK);
  40         X86_CS = v_rdw((num << 2) + 2);
  41         X86_IP = v_rdw((num << 2));
  42 }
  43
  44 int v86_init()
  45 {
  46         X86EMU_intrFuncs intFuncs[256];
  47         X86EMU_pioFuncs pioFuncs = {
  48                 .inb = &x_inb,
  49                 .inw = &x_inw,
  50                 .inl = &x_inl,
  51                 .outb = &x_outb,
  52                 .outw = &x_outw,
  53                 .outl = &x_outl,
  54         };
  55
  56         X86EMU_memFuncs memFuncs = {
  57                 .rdb = &v_rdb,
  58                 .rdw = &v_rdw,
  59                 .rdl = &v_rdl,
  60                 .wrb = &v_wrb,
  61                 .wrw = &v_wrw,
  62                 .wrl = &v_wrl,
  63         };
  64
  65         int i;
  66
  67         v86_mem_init();
  68
  69         stack = v86_mem_alloc(DEFAULT_STACK_SIZE);
  70         X86_SS = stack >> 4;
  71         X86_ESP = DEFAULT_STACK_SIZE;
  72
  73         halt = v86_mem_alloc(0x100);
  74         v_wrb(halt, 0xF4);
  75
  76         X86EMU_setupPioFuncs(&pioFuncs);
  77         X86EMU_setupMemFuncs(&memFuncs);
  78
  79         /* Setup interrupt handlers */
  80         for (i = 0; i < 256; i++) {
  81                 intFuncs[i] = x86emu_do_int;
  82         }
  83         X86EMU_setupIntrFuncs(intFuncs);
  84
  85         /* Set the default flags */
  86         X86_EFLAGS = X86_IF_MASK | X86_IOPL_MASK;
  87
  88         ioperm(0, 1024, 1);
  89         iopl(3);
  90
  91         return 0;
  92 }
  93
  94 void v86_cleanup()
  95 {
  96         v86_mem_cleanup();
  97 }
  98
  99 void rconv_v86_to_x86emu(struct v86_regs *rs)
 100 {
 101         X86_EAX = rs->eax;
 102         X86_EBX = rs->ebx;
 103         X86_ECX = rs->ecx;
 104         X86_EDX = rs->edx;
 105         X86_EDI = rs->edi;
 106         X86_ESI = rs->esi;
 107         X86_EBP = rs->ebp;
 108         X86_ESP = rs->esp;
 109         X86_EFLAGS = rs->eflags;
 110         X86_EIP = rs->eip;
 111         X86_CS  = rs->cs;
 112         X86_DS  = rs->ds;
 113         X86_ES  = rs->es;
 114         X86_FS  = rs->fs;
 115         X86_GS  = rs->gs;
 116 }
 117
 118 void rconv_x86emu_to_v86(struct v86_regs *rd)
 119 {
 120         rd->eax = X86_EAX;
 121         rd->ebx = X86_EBX;
 122         rd->ecx = X86_ECX;
 123         rd->edx = X86_EDX;
 124         rd->edi = X86_EDI;
 125         rd->esi = X86_ESI;
 126         rd->ebp = X86_EBP;
 127         rd->esp = X86_ESP;
 128         rd->eflags = X86_EFLAGS;
 129         rd->eip = X86_EIP;
 130         rd->cs  = X86_CS;
 131         rd->ds  = X86_DS;
 132         rd->es  = X86_ES;
 133         rd->fs  = X86_FS;
 134         rd->gs  = X86_GS;
 135 }
 136
 137 /*
 138  * Perform a simulated interrupt call.
 139  */
 140 int v86_int(int num, struct v86_regs *regs)
 141 {
 142         rconv_v86_to_x86emu(regs);
 143
 144         X86_GS = 0;
 145         X86_FS = 0;
 146         X86_DS = 0x0040;
 147         X86_CS  = v_rdw((num << 2) + 2);
 148         X86_EIP = v_rdw((num << 2));
 149         X86_SS = stack >> 4;
 150         X86_ESP = DEFAULT_STACK_SIZE;
 151         X86_EFLAGS = X86_IF_MASK | X86_IOPL_MASK;
 152
 153         pushw(X86_EFLAGS);
 154         pushw((halt >> 4));
 155         pushw(0x0);
 156
 157         X86EMU_exec();
 158
 159         rconv_x86emu_to_v86(regs);
 160         return 0;
 161 }
 162
 163 void v86_dump_regs()
 164 {
 165         ulog(
 166                 "EAX=0x%8.8lx, EBX=0x%8.8lx, ECX=0x%8.8lx, EDX=0x%8.8lx\n",
 167                 (unsigned long)X86_EAX, (unsigned long)X86_EBX,
 168                 (unsigned long)X86_ECX, (unsigned long)X86_EDX);
 169         ulog(
 170                 "ESP=0x%8.8lx, EBP=0x%8.8lx, ESI=0x%8.8lx, EDI=0x%8.8lx\n",
 171                 (unsigned long)X86_ESP, (unsigned long)X86_EBP,
 172                 (unsigned long)X86_ESI, (unsigned long)X86_EDI);
 173     ulog(
 174                 "CS=0x%4.4x, SS=0x%4.4x,"
 175                 " DS=0x%4.4x, ES=0x%4.4x, FS=0x%4.4x, GS=0x%4.4x\n",
 176                 X86_CS, X86_SS, X86_DS, X86_ES, X86_FS, X86_GS);
 177     ulog(
 178                 "EIP=0x%8.8lx, EFLAGS=0x%8.8lx\n",
 179                 (unsigned long)X86_EIP, (unsigned long)X86_EFLAGS);
 180 }
 181