blob: 1c3044bb069be92c40a9c6e5f9317ebc505c670b [file] [log] [blame]
Kevin O'Connorf076a3e2008-02-25 22:25:15 -05001// Code to access multiple segments within gcc.
2//
3// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
4//
5// This file may be distributed under the terms of the GNU GPLv3 license.
6
7#define READ8_SEG(SEG, var) ({ \
8 u8 __value; \
9 __asm__ __volatile__("movb %%" #SEG ":%1, %b0" \
10 : "=Qi"(__value) : "m"(var)); \
11 __value; })
12#define READ16_SEG(SEG, var) ({ \
13 u16 __value; \
14 __asm__ __volatile__("movw %%" #SEG ":%1, %w0" \
15 : "=ri"(__value) : "m"(var)); \
16 __value; })
17#define READ32_SEG(SEG, var) ({ \
18 u32 __value; \
19 __asm__ __volatile__("movl %%" #SEG ":%1, %0" \
20 : "=ri"(__value) : "m"(var)); \
21 __value; })
22#define WRITE8_SEG(SEG, var, value) \
23 __asm__ __volatile__("movb %b0, %%" #SEG ":%1" \
24 : : "Q"(value), "m"(var))
25#define WRITE16_SEG(SEG, var, value) \
26 __asm__ __volatile__("movw %w0, %%" #SEG ":%1" \
27 : : "r"(value), "m"(var))
28#define WRITE32_SEG(SEG, var, value) \
29 __asm__ __volatile__("movl %0, %%" #SEG ":%1" \
30 : : "r"(value), "m"(var))
31
32#define GET_VAR(seg, var) ({ \
33 typeof(var) __val; \
34 if (__builtin_types_compatible_p(typeof(__val), u8)) \
35 __val = READ8_SEG(seg, var); \
36 else if (__builtin_types_compatible_p(typeof(__val), u16)) \
37 __val = READ16_SEG(seg, var); \
38 else if (__builtin_types_compatible_p(typeof(__val), u32)) \
39 __val = READ32_SEG(seg, var); \
40 __val; })
41
42#define SET_VAR(seg, var, val) do { \
43 if (__builtin_types_compatible_p(typeof(var), u8)) \
44 WRITE8_SEG(seg, var, (val)); \
45 else if (__builtin_types_compatible_p(typeof(var), u16)) \
46 WRITE16_SEG(seg, var, (val)); \
47 else if (__builtin_types_compatible_p(typeof(var), u32)) \
48 WRITE32_SEG(seg, var, (val)); \
49 } while (0)
50
51#define SET_SEG(SEG, value) \
52 __asm__ __volatile__("movw %w0, %%" #SEG : : "r"(value))
53#define GET_SEG(SEG) ({ \
54 u16 __seg; \
55 __asm__ __volatile__("movw %%" #SEG ", %w0" : "=r"(__seg)); \
56 __seg;})
57