// Code to access multiple segments within gcc. // // Copyright (C) 2008 Kevin O'Connor // // This file may be distributed under the terms of the GNU GPLv3 license. #ifndef __FARPTR_H #define __FARPTR_H #include "ioport.h" // insb // Dummy definitions used to make sure gcc understands dependencies // between SET_SEG and GET/READ/WRITE_SEG macros. extern u16 __segment_ES, __segment_CS, __segment_DS, __segment_SS; 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) \ : "m"(var), "m"(__segment_ ## SEG)) #define READ16_SEG(SEG, value, var) \ __asm__("movw %%" #SEG ":%1, %w0" : "=ri"(value) \ : "m"(var), "m"(__segment_ ## SEG)) #define READ32_SEG(SEG, value, var) \ __asm__("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); \ } while (0) #define WRITE8_SEG(SEG, var, value) \ __asm__("movb %b1, %%" #SEG ":%0" : "=m"(var) \ : "Q"(value), "m"(__segment_ ## SEG)) #define WRITE16_SEG(SEG, var, value) \ __asm__("movw %w1, %%" #SEG ":%0" : "=m"(var) \ : "r"(value), "m"(__segment_ ## SEG)) #define WRITE32_SEG(SEG, var, value) \ __asm__("movl %1, %%" #SEG ":%0" : "=m"(var) \ : "r"(value), "m"(__segment_ ## SEG)) #define WRITE64_SEG(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); \ } 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(); #define __GET_VAR(seg, var) ({ \ typeof(var) __val; \ if (sizeof(__val) == 1) \ READ8_SEG(seg, __val, var); \ else if (sizeof(__val) == 2) \ READ16_SEG(seg, __val, var); \ else if (sizeof(__val) == 4) \ READ32_SEG(seg, __val, var); \ else if (sizeof(__val) == 8) \ READ64_SEG(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(); \ } while (0) // Macros for accessing a variable in another segment. (They // automatically update the %es segment and then make the appropriate // access.) #define __GET_FARVAR(seg, var) ({ \ SET_SEG(ES, (seg)); \ GET_VAR(ES, (var)); }) #define __SET_FARVAR(seg, var, val) do { \ typeof(var) __sfv_val = (val); \ SET_SEG(ES, (seg)); \ SET_VAR(ES, (var), __sfv_val); \ } while (0) // Macros for accesssing a 32bit pointer from 16bit real mode. (They // automatically update the %es segment, break the pointer into // segment/offset, and then make the access.) #define __GET_FARPTR(ptr) ({ \ typeof(&(ptr)) __ptr = &(ptr); \ GET_FARVAR(FARPTR_TO_SEG(__ptr) \ , *(typeof(__ptr))FARPTR_TO_OFFSET(__ptr)); }) #define __SET_FARPTR(ptr, val) do { \ typeof (&(ptr)) __ptr = &(ptr); \ SET_FARVAR(FARPTR_TO_SEG(__ptr) \ , *(typeof(__ptr))FARPTR_TO_OFFSET(__ptr) \ , (val)); \ } while (0) // Macros for converting to/from 32bit style pointers to their // equivalent 16bit segment/offset values. #define FARPTR_TO_SEG(p) (((u32)(p)) >> 4) #define FARPTR_TO_OFFSET(p) (((u32)(p)) & 0xf) #define MAKE_FARPTR(seg,off) ((void*)(((u32)(seg)<<4)+(u32)(off))) #if MODE16 == 1 // Definitions when in 16 bit 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 SET_SEG(SEG, value) __SET_SEG(SEG, (value)) #define GET_SEG(SEG) __GET_SEG(SEG) #define GET_FARPTR(ptr) __GET_FARPTR(ptr) #define SET_FARPTR(ptr, val) __SET_FARPTR((ptr), (val)) static inline void insb_far(u16 port, void *farptr, u16 count) { SET_SEG(ES, FARPTR_TO_SEG(farptr)); insb(port, (u8*)FARPTR_TO_OFFSET(farptr), count); } static inline void insw_far(u16 port, void *farptr, u16 count) { SET_SEG(ES, FARPTR_TO_SEG(farptr)); insw(port, (u16*)FARPTR_TO_OFFSET(farptr), count); } static inline void insl_far(u16 port, void *farptr, u16 count) { SET_SEG(ES, FARPTR_TO_SEG(farptr)); insl(port, (u32*)FARPTR_TO_OFFSET(farptr), count); } static inline void outsb_far(u16 port, void *farptr, u16 count) { SET_SEG(ES, FARPTR_TO_SEG(farptr)); outsb(port, (u8*)FARPTR_TO_OFFSET(farptr), count); } static inline void outsw_far(u16 port, void *farptr, u16 count) { SET_SEG(ES, FARPTR_TO_SEG(farptr)); outsw(port, (u16*)FARPTR_TO_OFFSET(farptr), count); } static inline void outsl_far(u16 port, void *farptr, u16 count) { SET_SEG(ES, FARPTR_TO_SEG(farptr)); outsl(port, (u32*)FARPTR_TO_OFFSET(farptr), count); } #else // In 32-bit mode there is no need to mess with the segments. #define GET_FARVAR(seg, var) \ (*((typeof(&(var)))MAKE_FARPTR((seg), (u32)&(var)))) #define SET_FARVAR(seg, var, val) \ do { GET_FARVAR((seg), (var)) = (val); } while (0) #define GET_VAR(seg, var) (var) #define SET_VAR(seg, var, val) do { (var) = (val); } while (0) #define SET_SEG(SEG, value) ((void)(value)) #define GET_SEG(SEG) 0 #define GET_FARPTR(ptr) (ptr) #define SET_FARPTR(ptr, val) do { (ptr) = (val); } while (0) #define insb_far(port, farptr, count) insb(port, farptr, count) #define insw_far(port, farptr, count) insw(port, farptr, count) #define insl_far(port, farptr, count) insl(port, farptr, count) #define outsb_far(port, farptr, count) outsb(port, farptr, count) #define outsw_far(port, farptr, count) outsw(port, farptr, count) #define outsl_far(port, farptr, count) outsl(port, farptr, count) #endif #endif // farptr.h