Cleanup and improve CPU feature detection (#104)

* Clean up CPU feature detection and per-CPU data initialization code.
* Enforce minimum system requirements (Pentium or later).

include/kernel/infrastructure/i686/asm/cpuinfo.h

@@ -34,21 +34,17 @@
 
 /* features */
 
-#define CPUINFO_FEATURE_CPUID       (1<<0)
+#define CPUINFO_FEATURE_SYSENTER    (1<<0)
 
-#define CPUINFO_FEATURE_SYSENTER    (1<<1)
+#define CPUINFO_FEATURE_SYSCALL     (1<<1)
 
-#define CPUINFO_FEATURE_SYSCALL     (1<<2)
+#define CPUINFO_FEATURE_LOCAL_APIC  (1<<2)
 
-#define CPUINFO_FEATURE_LOCAL_APIC  (1<<3)
+#define CPUINFO_FEATURE_PAE         (1<<3)
 
-#define CPUINFO_FEATURE_PAE         (1<<4)
+#define CPUINFO_FEATURE_PGE         (1<<4)
 
-#define CPUINFO_FEATURE_PGE         (1<<5)
-
-#define CPUINFO_FEATURE_PSE         (1<<6)
-
-#define CPUINFO_FEATURE_NOEXEC      (1<<7)
+#define CPUINFO_FEATURE_PSE         (1<<5)
 
 /* vendors */
 

include/kernel/infrastructure/i686/cpuinfo.h

@@ -37,21 +37,21 @@
 #include <stdint.h>
 
 typedef struct {
-    unsigned int     maxphyaddr;
-    unsigned int     dcache_alignment;
-    uint32_t         features;
-    int              vendor;
-    int              family;
-    int              model;
-    int              stepping;
+    unsigned int    maxphyaddr;
+    unsigned int    dcache_alignment;
+    uint32_t        features;
+    int             vendor;
+    unsigned int    family;
+    unsigned int    model;
+    unsigned int    stepping;
 } cpuinfo_t;
 
-extern cpuinfo_t cpuinfo;
+extern cpuinfo_t bsp_cpuinfo;
 
 void detect_cpu_features(void);
 
 static inline bool cpu_has_feature(uint32_t mask) {
-    return (cpuinfo.features & mask) == mask;
+    return (bsp_cpuinfo.features & mask) == mask;
 }
 
 #endif

include/kernel/infrastructure/i686/isa/instrs.h

@@ -41,6 +41,15 @@ typedef struct {
     uint32_t edx;
 } x86_cpuid_regs_t;
 
+typedef struct {
+    x86_cpuid_regs_t    basic0;
+    x86_cpuid_regs_t    basic1;
+    x86_cpuid_regs_t    ext0;
+    x86_cpuid_regs_t    ext1;
+    x86_cpuid_regs_t    ext8;
+    bool                ext8_valid;
+} x86_cpuid_leafs;
+
 void cli(void);
 
 void sti(void);