#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 0x0001
struct 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
