+static inline u16 get_ebda_seg(void) {
+ return GET_BDA(ebda_seg);
+}
+static inline struct extended_bios_data_area_s *
+get_ebda_ptr(void)
+{
+ ASSERT32FLAT();
+ return MAKE_FLATPTR(get_ebda_seg(), 0);
+}
+#define GET_EBDA2(eseg, var) \
+ GET_FARVAR(eseg, ((struct extended_bios_data_area_s *)0)->var)
+#define SET_EBDA2(eseg, var, val) \
+ SET_FARVAR(eseg, ((struct extended_bios_data_area_s *)0)->var, (val))
+#define GET_EBDA(var) \
+ GET_EBDA2(get_ebda_seg(), var)
+#define SET_EBDA(var, val) \
+ SET_EBDA2(get_ebda_seg(), var, (val))
+
+#define EBDA_OFFSET_TOP_STACK \
+ offsetof(struct extended_bios_data_area_s, extra_stack[ \
+ FIELD_SIZEOF(struct extended_bios_data_area_s \
+ , extra_stack)])
+
+
+/****************************************************************
+ * Global variables
+ ****************************************************************/
+
+#if MODE16 == 0 && MODESEGMENT == 1
+// In 32bit segmented mode %cs may not be readable and the code may be
+// relocated. The entry code sets up %gs with a readable segment and
+// the code offset can be determined by get_global_offset().
+#define GLOBAL_SEGREG GS
+static inline u32 __attribute_const get_global_offset(void) {
+ u32 ret;
+ asm(" calll 1f\n"
+ "1:popl %0\n"
+ " subl $1b, %0"
+ : "=r"(ret));
+ return ret;
+}
+#else
+#define GLOBAL_SEGREG CS
+static inline u32 __attribute_const get_global_offset(void) {
+ return 0;
+}
+#endif
+static inline u16 get_global_seg(void) {
+ return GET_SEG(GLOBAL_SEGREG);
+}
+#define GET_GLOBAL(var) \
+ GET_VAR(GLOBAL_SEGREG, *(typeof(&(var)))((void*)&(var) \
+ + get_global_offset()))
+#define SET_GLOBAL(var, val) do { \
+ ASSERT32FLAT(); \
+ (var) = (val); \
+ } while (0)
+#if MODESEGMENT
+#define GLOBALFLAT2GLOBAL(var) ((typeof(var))((void*)(var) - BUILD_BIOS_ADDR))
+#else
+#define GLOBALFLAT2GLOBAL(var) (var)
+#endif
+// Access a "flat" pointer known to point to the f-segment.
+#define GET_GLOBALFLAT(var) GET_GLOBAL(*GLOBALFLAT2GLOBAL(&(var)))