#ifndef _LINUX_VM86_H#define _LINUX_VM86_H/* * I'm guessing at the VIF/VIP flag usage, but hope that this is how * the Pentium uses them. Linux will return from vm86 mode when both * VIF and VIP is set. * * On a Pentium, we could probably optimize the virtual flags directly * in the eflags register instead of doing it "by hand" in vflags... * * Linus */#define TF_MASK		0x00000100#define IF_MASK		0x00000200#define IOPL_MASK	0x00003000#define NT_MASK		0x00004000#define VM_MASK		0x00020000#define AC_MASK		0x00040000#define VIF_MASK	0x00080000	/* virtual interrupt flag */#define VIP_MASK	0x00100000	/* virtual interrupt pending */#define ID_MASK		0x00200000#define BIOSSEG		0x0f000#define CPU_086		0#define CPU_186		1#define CPU_286		2#define CPU_386		3#define CPU_486		4#define CPU_586		5/* * Return values for the 'vm86()' system call */#define VM86_TYPE(retval)	((retval) & 0xff)#define VM86_ARG(retval)	((retval) >> 8)#define VM86_SIGNAL	0	/* return due to signal */#define VM86_UNKNOWN	1	/* unhandled GP fault - IO-instruction or similar */#define VM86_INTx	2	/* int3/int x instruction (ARG = x) */#define VM86_STI	3	/* sti/popf/iret instruction enabled virtual interrupts *//* * Additional return values when invoking new vm86() */#define VM86_PICRETURN	4	/* return due to pending PIC request */#define VM86_TRAP	6	/* return due to DOS-debugger request *//* * function codes when invoking new vm86() */#define VM86_PLUS_INSTALL_CHECK	0#define VM86_ENTER		1#define VM86_ENTER_NO_BYPASS	2#define	VM86_REQUEST_IRQ	3#define VM86_FREE_IRQ		4#define VM86_GET_IRQ_BITS	5#define VM86_GET_AND_RESET_IRQ	6/* * This is the stack-layout seen by the user space program when we have * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout * is 'kernel_vm86_regs' (see below). */struct vm86_regs {/* * normal regs, with special meaning for the segment descriptors.. */	long ebx;	long ecx;	long edx;	long esi;	long edi;	long ebp;	long eax;	long __null_ds;	long __null_es;	long __null_fs;	long __null_gs;	long orig_eax;	long eip;	unsigned short cs, __csh;	long eflags;	long esp;	unsigned short ss, __ssh;/* * these are specific to v86 mode: */	unsigned short es, __esh;	unsigned short ds, __dsh;	unsigned short fs, __fsh;	unsigned short gs, __gsh;};struct revectored_struct {	unsigned long __map[8];			/* 256 bits */};struct vm86_struct {	struct vm86_regs regs;	unsigned long flags;	unsigned long screen_bitmap;	unsigned long cpu_type;	struct revectored_struct int_revectored;	struct revectored_struct int21_revectored;};/* * flags masks */#define VM86_SCREEN_BITMAP	0x0001struct vm86plus_info_struct {	unsigned long force_return_for_pic:1;	unsigned long vm86dbg_active:1;       /* for debugger */	unsigned long vm86dbg_TFpendig:1;     /* for debugger */	unsigned long unused:28;	unsigned long is_vm86pus:1;	      /* for vm86 internal use */	unsigned char vm86dbg_intxxtab[32];   /* for debugger */};struct vm86plus_struct {	struct vm86_regs regs;	unsigned long flags;	unsigned long screen_bitmap;	unsigned long cpu_type;	struct revectored_struct int_revectored;	struct revectored_struct int21_revectored;	struct vm86plus_info_struct vm86plus;};#ifdef __KERNEL__/* * This is the (kernel) stack-layout when we have done a "SAVE_ALL" from vm86 * mode - the main change is that the old segment descriptors aren't * useful any more and are forced to be zero by the kernel (and the * hardware when a trap occurs), and the real segment descriptors are * at the end of the structure. Look at ptrace.h to see the "normal" * setup. For user space layout see 'struct vm86_regs' above. */struct kernel_vm86_regs {/* * normal regs, with special meaning for the segment descriptors.. */	long ebx;	long ecx;	long edx;	long esi;	long edi;	long ebp;	long eax;	long __null_ds;	long __null_es;	long orig_eax;	long eip;	unsigned short cs, __csh;	long eflags;	long esp;	unsigned short ss, __ssh;/* * these are specific to v86 mode: */	unsigned short es, __esh;	unsigned short ds, __dsh;	unsigned short fs, __fsh;	unsigned short gs, __gsh;};struct kernel_vm86_struct {	struct kernel_vm86_regs regs;/* * the below part remains on the kernel stack while we are in VM86 mode. * 'tss.esp0' then contains the address of VM86_TSS_ESP0 below, and when we * get forced back from VM86, the CPU and "SAVE_ALL" will restore the above * 'struct kernel_vm86_regs' with the then actual values. * Therefore, pt_regs in fact points to a complete 'kernel_vm86_struct' * in kernelspace, hence we need not reget the data from userspace. */#define VM86_TSS_ESP0 flags	unsigned long flags;	unsigned long screen_bitmap;	unsigned long cpu_type;	struct revectored_struct int_revectored;	struct revectored_struct int21_revectored;	struct vm86plus_info_struct vm86plus;	struct pt_regs *regs32;   /* here we save the pointer to the old regs *//* * The below is not part of the structure, but the stack layout continues * this way. In front of 'return-eip' may be some data, depending on * compilation, so we don't rely on this and save the pointer to 'oldregs' * in 'regs32' above. * However, with GCC-2.7.2 and the current CFLAGS you see exactly this:	long return-eip;        from call to vm86()	struct pt_regs oldregs;  user space registers as saved by syscall */};void handle_vm86_fault(struct kernel_vm86_regs *, long);int handle_vm86_trap(struct kernel_vm86_regs *, long, int);#endif /* __KERNEL__ */#endif