#ifndef MELVIX_SYSTEM_H #define MELVIX_SYSTEM_H /** * Initialize the basic features of the OS */ void init(); /** * The ASM registers as packed structure */ typedef struct __attribute__ ((packed)) { unsigned short di, si, bp, sp, bx, dx, cx, ax; unsigned short gs, fs, es, ds, eflags; } regs16_t; /** * Execute BIOS interrupts by switching to real mode * @param intnum The interrupt number (e.g. 0x10) * @param regs The ASM registers */ extern void int32(unsigned char intnum, regs16_t *regs); /** * ASM segment:offset pointer */ struct far_ptr { union { uint32_t ptr; struct { uint16_t offset, segment; }; }; } __attribute__ ((packed)); /** * Get offset from ASM segment:offset pointer */ static inline uint16_t get_offset(const volatile void *p) { return (uint16_t) (uintptr_t) p & 0x000F; } /** * Get segment from ASM segment:offset pointer */ static inline uint16_t get_segment(const volatile void *p) { return (uint16_t) (((uintptr_t) p) >> 4); } /** * Convert pointer to far_ptr * @param __ptr The ASM segment:offset pointer * @return The new far pointer */ static inline struct far_ptr FAR_PTR(void *__ptr) { struct far_ptr __fptr; __fptr.offset = get_offset(__ptr); __fptr.segment = get_segment(__ptr); return __fptr; } /** * Get pointer from ASM segment:offset far pointer * @param fptr The ASM far pointer * @return The normalized pointer */ static inline void *get_ptr(struct far_ptr fptr) { return (void *) (unsigned long) ((fptr.segment << 4) + fptr.offset); } #endif