// Code to access multiple segments within gcc.
//
-// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#ifndef __FARPTR_H
extern u16 __segment_FS, __segment_GS;
// Low level macros for reading/writing memory via a segment selector.
-#define READ8_SEG(SEG, value, var) \
- __asm__("movb %%" #SEG ":%1, %b0" : "=Qi"(value) \
+#define READ8_SEG(prefix, SEG, value, var) \
+ __asm__(prefix "movb %%" #SEG ":%1, %b0" : "=Qi"(value) \
: "m"(var), "m"(__segment_ ## SEG))
-#define READ16_SEG(SEG, value, var) \
- __asm__("movw %%" #SEG ":%1, %w0" : "=ri"(value) \
+#define READ16_SEG(prefix, SEG, value, var) \
+ __asm__(prefix "movw %%" #SEG ":%1, %w0" : "=ri"(value) \
: "m"(var), "m"(__segment_ ## SEG))
-#define READ32_SEG(SEG, value, var) \
- __asm__("movl %%" #SEG ":%1, %0" : "=ri"(value) \
+#define READ32_SEG(prefix, SEG, value, var) \
+ __asm__(prefix "movl %%" #SEG ":%1, %0" : "=ri"(value) \
: "m"(var), "m"(__segment_ ## SEG))
-#define READ64_SEG(SEG, value, var) do { \
- union u64_u32_u *__w64_ptr = (union u64_u32_u *)&(value); \
- union u64_u32_u *__r64_ptr = (union u64_u32_u *)&(var); \
- READ32_SEG(SEG, __w64_ptr->hi, __r64_ptr->hi); \
- READ32_SEG(SEG, __w64_ptr->lo, __r64_ptr->lo); \
+#define READ64_SEG(prefix, SEG, value, var) do { \
+ union u64_u32_u __value; \
+ union u64_u32_u *__r64_ptr = (union u64_u32_u *)&(var); \
+ READ32_SEG(prefix, SEG, __value.hi, __r64_ptr->hi); \
+ READ32_SEG(prefix, SEG, __value.lo, __r64_ptr->lo); \
+ *(u64*)&(value) = __value.val; \
} while (0)
-#define WRITE8_SEG(SEG, var, value) \
- __asm__("movb %b1, %%" #SEG ":%0" : "=m"(var) \
+#define WRITE8_SEG(prefix, SEG, var, value) \
+ __asm__(prefix "movb %b1, %%" #SEG ":%0" : "=m"(var) \
: "Q"(value), "m"(__segment_ ## SEG))
-#define WRITE16_SEG(SEG, var, value) \
- __asm__("movw %w1, %%" #SEG ":%0" : "=m"(var) \
+#define WRITE16_SEG(prefix, SEG, var, value) \
+ __asm__(prefix "movw %w1, %%" #SEG ":%0" : "=m"(var) \
: "r"(value), "m"(__segment_ ## SEG))
-#define WRITE32_SEG(SEG, var, value) \
- __asm__("movl %1, %%" #SEG ":%0" : "=m"(var) \
+#define WRITE32_SEG(prefix, SEG, var, value) \
+ __asm__(prefix "movl %1, %%" #SEG ":%0" : "=m"(var) \
: "r"(value), "m"(__segment_ ## SEG))
-#define WRITE64_SEG(SEG, var, value) do { \
+#define WRITE64_SEG(prefix, SEG, var, value) do { \
union u64_u32_u __value; \
union u64_u32_u *__w64_ptr = (union u64_u32_u *)&(var); \
- __value.val = (value); \
- WRITE32_SEG(SEG, __w64_ptr->hi, __value.hi); \
- WRITE32_SEG(SEG, __w64_ptr->lo, __value.lo); \
+ typeof(var) __value_tmp = (value); \
+ __value.val = *(u64*)&__value_tmp; \
+ WRITE32_SEG(prefix, SEG, __w64_ptr->hi, __value.hi); \
+ WRITE32_SEG(prefix, SEG, __w64_ptr->lo, __value.lo); \
} while (0)
-// Low level macros for getting/setting a segment register.
-#define __SET_SEG(SEG, value) \
- __asm__("movw %w1, %%" #SEG : "=m"(__segment_ ## SEG) \
- : "r"(value))
-#define __GET_SEG(SEG) ({ \
- u16 __seg; \
- __asm__("movw %%" #SEG ", %w0" : "=r"(__seg) \
- : "m"(__segment_ ## SEG)); \
- __seg;})
-
// Macros for automatically choosing the appropriate memory size
// access method.
-extern void __force_link_error__unknown_type();
+extern void __force_link_error__unknown_type(void);
-#define __GET_VAR(seg, var) ({ \
+#define __GET_VAR(prefix, seg, var) ({ \
typeof(var) __val; \
if (sizeof(__val) == 1) \
- READ8_SEG(seg, __val, var); \
+ READ8_SEG(prefix, seg, __val, var); \
else if (sizeof(__val) == 2) \
- READ16_SEG(seg, __val, var); \
+ READ16_SEG(prefix, seg, __val, var); \
else if (sizeof(__val) == 4) \
- READ32_SEG(seg, __val, var); \
+ READ32_SEG(prefix, seg, __val, var); \
else if (sizeof(__val) == 8) \
- READ64_SEG(seg, __val, var); \
+ READ64_SEG(prefix, seg, __val, var); \
else \
__force_link_error__unknown_type(); \
__val; })
-#define __SET_VAR(seg, var, val) do { \
- if (sizeof(var) == 1) \
- WRITE8_SEG(seg, var, (val)); \
- else if (sizeof(var) == 2) \
- WRITE16_SEG(seg, var, (val)); \
- else if (sizeof(var) == 4) \
- WRITE32_SEG(seg, var, (val)); \
- else if (sizeof(var) == 8) \
- WRITE64_SEG(seg, var, (val)); \
- else \
- __force_link_error__unknown_type(); \
+#define __SET_VAR(prefix, seg, var, val) do { \
+ if (sizeof(var) == 1) \
+ WRITE8_SEG(prefix, seg, var, (val)); \
+ else if (sizeof(var) == 2) \
+ WRITE16_SEG(prefix, seg, var, (val)); \
+ else if (sizeof(var) == 4) \
+ WRITE32_SEG(prefix, seg, var, (val)); \
+ else if (sizeof(var) == 8) \
+ WRITE64_SEG(prefix, seg, var, (val)); \
+ else \
+ __force_link_error__unknown_type(); \
} while (0)
+// Low level macros for getting/setting a segment register.
+#define __SET_SEG(SEG, value) \
+ __asm__("movw %w1, %%" #SEG : "=m"(__segment_ ## SEG) \
+ : "rm"(value))
+#define __GET_SEG(SEG) ({ \
+ u16 __seg; \
+ __asm__("movw %%" #SEG ", %w0" : "=rm"(__seg) \
+ : "m"(__segment_ ## SEG)); \
+ __seg;})
+
// Macros for accessing a variable in another segment. (They
// automatically update the %es segment and then make the appropriate
// access.)
#define MAKE_FLATPTR(seg,off) ((void*)(((u32)(seg)<<4)+(u32)(off)))
-#if MODE16 == 1
+#if MODESEGMENT == 1
-// Definitions when in 16 bit mode.
+// Definitions when using segmented mode.
#define GET_FARVAR(seg, var) __GET_FARVAR((seg), (var))
#define SET_FARVAR(seg, var, val) __SET_FARVAR((seg), (var), (val))
-#define GET_VAR(seg, var) __GET_VAR(seg, (var))
-#define SET_VAR(seg, var, val) __SET_VAR(seg, (var), (val))
+#define GET_VAR(seg, var) __GET_VAR("", seg, (var))
+#define SET_VAR(seg, var, val) __SET_VAR("", seg, (var), (val))
#define SET_SEG(SEG, value) __SET_SEG(SEG, (value))
#define GET_SEG(SEG) __GET_SEG(SEG)
#define GET_FLATPTR(ptr) __GET_FLATPTR(ptr)
#else
-// In 32-bit mode there is no need to mess with the segments.
+// In 32-bit flat mode there is no need to mess with the segments.
#define GET_FARVAR(seg, var) \
(*((typeof(&(var)))MAKE_FLATPTR((seg), &(var))))
#define SET_FARVAR(seg, var, val) \
#endif
+// Definition for common 16bit segment/offset pointers.
+struct segoff_s {
+ union {
+ struct {
+ u16 offset;
+ u16 seg;
+ };
+ u32 segoff;
+ };
+};
+#define SEGOFF(s,o) ({struct segoff_s __so; __so.offset=(o); __so.seg=(s); __so;})
+
+static inline struct segoff_s FLATPTR_TO_SEGOFF(void *p) {
+ return SEGOFF(FLATPTR_TO_SEG(p), FLATPTR_TO_OFFSET(p));
+}
+static inline void *SEGOFF_TO_FLATPTR(struct segoff_s so) {
+ return MAKE_FLATPTR(so.seg, so.offset);
+}
+
#endif // farptr.h
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