diff options
Diffstat (limited to 'com32/include/com32.h')
| -rw-r--r-- | com32/include/com32.h | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/com32/include/com32.h b/com32/include/com32.h index 29656e47..5706683c 100644 --- a/com32/include/com32.h +++ b/com32/include/com32.h @@ -88,18 +88,35 @@ void __farcall(uint16_t __es, uint16_t __eo, * 0..0xFFFFF and real-mode style SEG:OFFS pointers. Note that a * 32-bit linear pointer is not compatible with a SEG:OFFS pointer * stored in two consecutive 16-bit words. + * + * Use OFFS_WRT() if you want to compute an offset relative to a + * specific segment. OFFS_VALID() will return whether or not the + * pointer is actually reachable from the target segment. */ -static inline uint16_t SEG(void *__p) +static inline uint16_t SEG(const volatile void *__p) { return (uint16_t)(((uintptr_t)__p) >> 4); } -static inline uint16_t OFFS(void *__p) +static inline uint16_t OFFS(const volatile void *__p) { /* The double cast here is to shut up gcc */ return (uint16_t)(uintptr_t)__p & 0x000F; } +static inline uint16_t OFFS_WRT(const volatile void *__p, uint16_t seg) +{ + return (uint16_t)((uintptr_t)__p - ((uintptr_t)seg << 4)); +} + +static inline int OFFS_VALID(const volatile void *__p, uint16_t seg) +{ + uintptr_t __segstart = (uintptr_t)seg << 4; + uintptr_t __ptr = (uintptr_t)__p; + + return (__ptr >= __segstart) && (__ptr <= __segstart+0xffff); +} + static inline void *MK_PTR(uint16_t __seg, uint16_t __offs) { return (void *)((__seg << 4) + __offs); |