kernel: string.h, gdt, msr, cpu and ist

kernel-src/include/arch/msr.h

@@ -0,0 +1,27 @@
+#ifndef _MSR_H
+#define _MSR_H
+
+#include <stdint.h>
+
+#define MSR_EFER 0xC0000080
+#define MSR_STAR 0xC0000081
+#define MSR_LSTAR 0xC0000082
+#define MSR_CSTAR 0xC0000083
+#define MSR_FMASK 0xC0000084
+#define MSR_FSBASE 0xC0000100
+#define MSR_GSBASE 0xC0000101
+#define MSR_KERNELGSBASE 0xC0000102
+
+static inline uint64_t rdmsr(uint32_t which) {
+	uint64_t low,high;
+	asm volatile("rdmsr" : "=a"(low), "=d"(high) : "c"(which));
+	return (high << 32) | low;
+}
+
+static inline void wrmsr(uint32_t which, uint64_t value) {
+	uint32_t low = value & 0xFFFFFFFF;
+	uint32_t high = (value >> 32) & 0xFFFFFFFF;
+	asm volatile("wrmsr" : : "a"(low), "d"(high), "c"(which));
+}
+
+#endif