Extract 'struct bregs' out of biosvar.h; clean up header includes.

1 files changed, 33 insertions, 0 deletions

diff --git a/src/util.c b/src/util.c
index 6b2d9dba..c4f61c5a 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1,4 +1,37 @@
+// Misc utility functions.
+//
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
 #include "util.h" // usleep
+#include "bregs.h" // struct bregs
+#include "config.h" // SEG_BIOS
+#include "farptr.h" // GET_FARPTR
+
+// Call a function with a specified register state.  Note that on
+// return, the interrupt enable/disable flag may be altered.
+inline void
+call16(struct bregs *callregs)
+{
+    asm volatile(
+#ifdef MODE16
+        "calll __call16\n"
+#else
+        "calll __call16_from32\n"
+#endif
+        : "+a" (callregs), "+m" (*callregs)
+        :
+        : "ebx", "ecx", "edx", "esi", "edi", "ebp", "cc");
+}
+
+inline void
+__call16_int(struct bregs *callregs, u16 offset)
+{
+    callregs->cs = SEG_BIOS;
+    callregs->ip = offset;
+    call16(callregs);
+}
 
 // Sum the bytes in the specified area.
 u8