1 #ifndef _LINUX_VM86_H 2 #define _LINUX_VM86_H 3 4 /* 5 * I'm guessing at the VIF/VIP flag usage, but hope that this is how 6 * the Pentium uses them. Linux will return from vm86 mode when both 7 * VIF and VIP is set. 8 * 9 * On a Pentium, we could probably optimize the virtual flags directly 10 * in the eflags register instead of doing it "by hand" in vflags... 11 * 12 * Linus 13 */ 14 15 #define TF_MASK 0x00000100 16 #define IF_MASK 0x00000200 17 #define IOPL_MASK 0x00003000 18 #define NT_MASK 0x00004000 19 #define VM_MASK 0x00020000 20 #define AC_MASK 0x00040000 21 #define VIF_MASK 0x00080000 /* virtual interrupt flag */ 22 #define VIP_MASK 0x00100000 /* virtual interrupt pending */ 23 #define ID_MASK 0x00200000 24 25 #define BIOSSEG 0x0f000 26 27 #define CPU_086 0 28 #define CPU_186 1 29 #define CPU_286 2 30 #define CPU_386 3 31 #define CPU_486 4 32 #define CPU_586 5 33 34 /* 35 * Return values for the 'vm86()' system call 36 */ 37 #define VM86_TYPE(retval) ((retval) & 0xff) 38 #define VM86_ARG(retval) ((retval) >> 8) 39 40 #define VM86_SIGNAL 0 /* return due to signal */ 41 #define VM86_UNKNOWN 1 /* unhandled GP fault - IO-instruction or similar */ 42 #define VM86_INTx 2 /* int3/int x instruction (ARG = x) */ 43 #define VM86_STI 3 /* sti/popf/iret instruction enabled virtual interrupts */ 44 45 /* 46 * Additional return values when invoking new vm86() 47 */ 48 #define VM86_PICRETURN 4 /* return due to pending PIC request */ 49 #define VM86_TRAP 6 /* return due to DOS-debugger request */ 50 51 /* 52 * function codes when invoking new vm86() 53 */ 54 #define VM86_PLUS_INSTALL_CHECK 0 55 #define VM86_ENTER 1 56 #define VM86_ENTER_NO_BYPASS 2 57 #define VM86_REQUEST_IRQ 3 58 #define VM86_FREE_IRQ 4 59 #define VM86_GET_IRQ_BITS 5 60 #define VM86_GET_AND_RESET_IRQ 6 61 62 /* 63 * This is the stack-layout seen by the user space program when we have 64 * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout 65 * is 'kernel_vm86_regs' (see below). 66 */ 67 68 struct vm86_regs { 69 /* 70 * normal regs, with special meaning for the segment descriptors.. 71 */ 72 long ebx; 73 long ecx; 74 long edx; 75 long esi; 76 long edi; 77 long ebp; 78 long eax; 79 long __null_ds; 80 long __null_es; 81 long __null_fs; 82 long __null_gs; 83 long orig_eax; 84 long eip; 85 unsigned short cs, __csh; 86 long eflags; 87 long esp; 88 unsigned short ss, __ssh; 89 /* 90 * these are specific to v86 mode: 91 */ 92 unsigned short es, __esh; 93 unsigned short ds, __dsh; 94 unsigned short fs, __fsh; 95 unsigned short gs, __gsh; 96 }; 97 98 struct revectored_struct { 99 unsigned long __map[8]; /* 256 bits */ 100 }; 101 102 struct vm86_struct { 103 struct vm86_regs regs; 104 unsigned long flags; 105 unsigned long screen_bitmap; 106 unsigned long cpu_type; 107 struct revectored_struct int_revectored; 108 struct revectored_struct int21_revectored; 109 }; 110 111 /* 112 * flags masks 113 */ 114 #define VM86_SCREEN_BITMAP 0x0001 115 116 struct vm86plus_info_struct { 117 unsigned long force_return_for_pic:1; 118 unsigned long vm86dbg_active:1; /* for debugger */ 119 unsigned long vm86dbg_TFpendig:1; /* for debugger */ 120 unsigned long unused:28; 121 unsigned long is_vm86pus:1; /* for vm86 internal use */ 122 unsigned char vm86dbg_intxxtab[32]; /* for debugger */ 123 }; 124 125 struct vm86plus_struct { 126 struct vm86_regs regs; 127 unsigned long flags; 128 unsigned long screen_bitmap; 129 unsigned long cpu_type; 130 struct revectored_struct int_revectored; 131 struct revectored_struct int21_revectored; 132 struct vm86plus_info_struct vm86plus; 133 }; 134 135 #ifdef __KERNEL__ 136 /* 137 * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86 138 * mode - the main change is that the old segment descriptors aren't 139 * useful any more and are forced to be zero by the kernel (and the 140 * hardware when a trap occurs), and the real segment descriptors are 141 * at the end of the structure. Look at ptrace.h to see the "normal" 142 * setup. For user space layout see 'struct vm86_regs' above. 143 */ 144 145 struct kernel_vm86_regs { 146 /* 147 * normal regs, with special meaning for the segment descriptors.. 148 */ 149 long ebx; 150 long ecx; 151 long edx; 152 long esi; 153 long edi; 154 long ebp; 155 long eax; 156 long __null_ds; 157 long __null_es; 158 long orig_eax; 159 long eip; 160 unsigned short cs, __csh; 161 long eflags; 162 long esp; 163 unsigned short ss, __ssh; 164 /* 165 * these are specific to v86 mode: 166 */ 167 unsigned short es, __esh; 168 unsigned short ds, __dsh; 169 unsigned short fs, __fsh; 170 unsigned short gs, __gsh; 171 }; 172 173 struct kernel_vm86_struct { 174 struct kernel_vm86_regs regs; 175 /* 176 * the below part remains on the kernel stack while we are in VM86 mode. 177 * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we 178 * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above 179 * 'struct kernel_vm86_regs' with the then actual values. 180 * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct' 181 * in kernelspace, hence we need not reget the data from userspace. 182 */ 183 #define VM86_TSS_ESP0 flags 184 unsigned long flags; 185 unsigned long screen_bitmap; 186 unsigned long cpu_type; 187 struct revectored_struct int_revectored; 188 struct revectored_struct int21_revectored; 189 struct vm86plus_info_struct vm86plus; 190 struct pt_regs *regs32; /* here we save the pointer to the old regs */ 191 /* 192 * The below is not part of the structure, but the stack layout continues 193 * this way. In front of 'return-eip' may be some data, depending on 194 * compilation, so we don't rely on this and save the pointer to 'oldregs' 195 * in 'regs32' above. 196 * However, with GCC-2.7.2 and the current CFLAGS you see exactly this: 197 198 long return-eip; from call to vm86() 199 struct pt_regs oldregs; user space registers as saved by syscall 200 */ 201 }; 202 203 void handle_vm86_fault(struct kernel_vm86_regs *, long); 204 int handle_vm86_trap(struct kernel_vm86_regs *, long, int); 205 206 #endif /* __KERNEL__ */ 207 208 #endif 209