[MODERN FEATURES] CPUID and MSR

kernel/arch/cpuid.c

@@ -0,0 +1,27 @@
+#include <cpuid.h>
+#include <stdint.h>
+#include <debug.h>
+
+uint32_t cpuid_features_b, cpuid_features_c, cpuid_features_d;
+uint32_t cpuid_featuresx_b, cpuid_featuresx_c, cpuid_featuresx_d;
+uint32_t cpuid_signature;
+uint32_t cpuid_max=0x0, cpuid_maxx=0x80000000;
+
+
+void cpuid(uint32_t code, uint32_t *a, uint32_t *b, uint32_t *c, uint32_t *d)
+{
+  uint32_t scrap;
+  if(!a) a = &scrap;
+  if(!b) b = &scrap;
+  if(!c) c = &scrap;
+  if(!d) d = &scrap;
+
+  if((code < CPUID_FUNCTIONX_VENDOR && code > cpuid_max) || code > cpuid_maxx)
+  {
+    *a = *b = *c = *d = -1;
+    return;
+  }
+
+  asm volatile("cpuid" : "=a"(*a), "=b"(*b), "=c"(*c), "=d"(*d) : "a"(code));
+}
+

kernel/arch/msr.c

@@ -0,0 +1,13 @@
+#include <stdint.h>
+
+uint64_t msr_read(uint32_t msr)
+{
+  uint64_t lo, hi;
+  asm volatile("rdmsr" : "=a"(lo), "=d"(hi) : "c"(msr));
+  return ((hi&0xFFFFFFFF) << 32) | (lo&0xFFFFFFFF);
+}
+
+void msr_write(uint32_t msr, uint64_t value)
+{
+  asm volatile("wrmsr" : : "a" (value&0xFFFFFFFF), "d"(value>>32), "c"(msr));
+}