tabs/kernel/inline_asm.c
2020-01-31 06:26:23 +01:00

100 lines
2.6 KiB
C

#ifndef INLINE_ASM_C
#define INLINE_ASM_C
#include <stdint.h>
#include "memory.c"
typedef struct {
uint16_t limit;
uint32_t base;
}__attribute__((packed)) gdt_desc;
typedef struct {
uint16_t limit_lower;
uint16_t base_lower;
uint8_t base_middle;
uint8_t access_byte;
uint8_t flags_limit_higher;
uint8_t base_higher;
}__attribute__((packed)) gdt_entry;
static inline void outb(uint16_t port, uint8_t val) {
asm volatile ( "outb %0, %1" : : "a"(val), "Nd"(port) );
}
static inline uint8_t inb(uint16_t port) {
uint8_t ret;
asm volatile ( "inb %1, %0"
: "=a"(ret)
: "Nd"(port) );
return ret;
}
static uint16_t inw(uint16_t port) {
uint16_t ret;
asm volatile ("inw %1, %0" : "=a" (ret) : "dN" (port));
return ret;
}
static void outw(uint16_t port, uint16_t val) {
asm volatile ("outw %0, %1" : : "a" (val), "dN" (port) );
}
static uint32_t inl(uint16_t port) {
uint32_t ret;
asm volatile ("inl %%dx, %%eax" : "=a" (ret) : "dN" (port));
return ret;
}
static void outl(uint16_t port, uint32_t val) {
asm volatile ("outl %%eax, %%dx" : : "dN" (port), "a" (val));
}
static inline void lidt(void* base, uint16_t size)
{ // This function works in 32 and 64bit mode
struct {
uint16_t length;
void* base;
} __attribute__((packed)) IDTR = { size, base };
asm ( "lidt %0" : : "m"(IDTR) ); // let the compiler choose an addressing mode
}
/** issue a single request to CPUID. Fits 'intel features', for instance
* note that even if only "eax" and "edx" are of interest, other registers
* will be modified by the operation, so we need to tell the compiler about it.
*/
static inline void cpuid(int code, uint32_t *a, uint32_t *d) {
asm volatile("cpuid":"=a"(*a),"=d"(*d):"a"(code):"ecx","ebx");
}
/** issue a complete request, storing general registers output as a string
*/
static inline int cpuid_string(int code, uint32_t where[4]) {
asm volatile("cpuid":"=a"(*where),"=b"(*(where+1)),
"=c"(*(where+2)),"=d"(*(where+3)):"a"(code));
return (int)where[0];
}
static inline void sgdt(gdt_desc* ret) {
asm volatile ("sgdt %0" : : "m"(*ret) : "memory");
}
static void * memcpy(void * restrict dest, const void * restrict src, long n) {
asm volatile("cld; rep movsb"
: "=c"((int){0})
: "D"(dest), "S"(src), "c"(n)
: "flags", "memory");
return dest;
}
static void * memset(void * dest, int c, long n) {
asm volatile("cld; rep stosb"
: "=c"((int){0})
: "D"(dest), "a"(c), "c"(n)
: "flags", "memory");
return dest;
}
#endif //INLINE ASM_C