diff options
Diffstat (limited to 'include/asm-i386/vm86.h')
| -rw-r--r-- | include/asm-i386/vm86.h | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/include/asm-i386/vm86.h b/include/asm-i386/vm86.h new file mode 100644 index 00000000000..40ec82c6914 --- /dev/null +++ b/include/asm-i386/vm86.h @@ -0,0 +1,208 @@ +#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 |