Use MSR to map framebuffer as WC (write-combining) = huge speed diff on real HW

src/arch/x86/cpuid.c

@@ -0,0 +1,20 @@
+/*
+ * @author  xamidev <xamidev@riseup.net>
+ * @brief   x86 CPU identification
+ * @license GPL-3.0-only
+ */
+
+#include <stdint.h>
+
+/*
+ * cpuid - Wrapper for CPUID instruction
+ * @leaf: Requested leaf
+ * @eax: EAX register value
+ * @ebx: EBX register value
+ * @ecx: ECX register value
+ * @edx: EDX register value
+*/
+void cpuid(uint32_t leaf, uint32_t* eax, uint32_t* ebx, uint32_t* ecx, uint32_t* edx)
+{
+    __asm__ volatile("cpuid" : "=a"(*eax), "=b"(*ebx), "=c"(*ecx), "=d"(*edx) : "a"(leaf));
+}