Last patch of the vm86 patch series from Jan Klötzke - thanks!:

* The new function vm86_do_int(struct vm86_state *state, uint8 vec) provides a
  facility to call BIOS interupt handlers. The function must only be called from
  a user thread context because the lower 1MB of the address space is used.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25610 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/arch/x86/arch_cpu.h

@@ -157,6 +157,37 @@ struct iframe {
 	uint32 user_ss;
 };
 
+struct vm86_iframe {
+	uint32 type;	// iframe type
+	uint32 __null_gs;
+	uint32 __null_fs;
+	uint32 __null_es;
+	uint32 __null_ds;
+	uint32 edi;
+	uint32 esi;
+	uint32 ebp;
+	uint32 __kern_esp;
+	uint32 ebx;
+	uint32 edx;
+	uint32 ecx;
+	uint32 eax;
+	uint32 orig_eax;
+	uint32 orig_edx;
+	uint32 vector;
+	uint32 error_code;
+	uint32 eip;
+	uint16 cs, __csh;
+	uint32 flags;
+	uint32 esp;
+	uint16 ss, __ssh;
+
+	/* vm86 mode specific part */
+	uint16 es, __esh;
+	uint16 ds, __dsh;
+	uint16 fs, __fsh;
+	uint16 gs, __gsh;
+};
+
 #define IFRAME_IS_USER(f) ( ((f)->cs == USER_CODE_SEG) \
                             || (((f)->flags & 0x20000) != 0 ))
 #define IFRAME_IS_VM86(f) ( ((f)->flags & 0x20000) != 0 )

headers/private/kernel/arch/x86/vm86.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2008 Jan Klötzke
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+#ifndef _VM86_H
+#define _VM86_H
+
+#include <OS.h>
+#include <arch_cpu.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define VM86_MIN_RAM_SIZE 0x1000
+#define RETURN_TO_32_INT  255
+
+struct vm86_state {
+	struct vm86_iframe regs;
+	area_id bios_area;
+	area_id ram_area;
+	unsigned int if_flag : 1;
+};
+
+status_t x86_vm86_enter(struct vm86_iframe *frame);
+void x86_vm86_return(struct vm86_iframe *frame, status_t retval);
+
+status_t vm86_prepare(struct vm86_state *state, unsigned int ram_size);
+void vm86_cleanup(struct vm86_state *state);
+status_t vm86_do_int(struct vm86_state *state, uint8 vec);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+