1 files changed, 40 insertions, 4 deletions

diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index 9b65d6e..40950f9 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -44,6 +44,8 @@
 #include <machine/intr.h>
 #include <machine/cdefs.h>
 #include <machine/isa/i8042var.h>
+#include <dev/cons/cons.h>
+#include <string.h>
 
 #define pr_trace(fmt, ...) kprintf("cpu: " fmt, ##__VA_ARGS__)
 #define pr_error(...) pr_trace(__VA_ARGS__)
@@ -185,9 +187,10 @@ enable_simd(void)
 }
 
 static void
-cpu_check_feat(struct cpu_info *ci)
+cpu_get_info(struct cpu_info *ci)
 {
-    uint32_t unused, ebx;
+    uint32_t eax, ebx, unused;
+    uint8_t ext_model, ext_family;
 
     /* Extended features */
     CPUID(0x07, unused, ebx, unused, unused);
@@ -195,6 +198,33 @@ cpu_check_feat(struct cpu_info *ci)
         ci->feat |= CPU_FEAT_SMEP;
     if (ISSET(ebx, BIT(20)))
         ci->feat |= CPU_FEAT_SMAP;
+
+    /*
+     * Processor info and feature bits
+     */
+    CPUID(0x01, eax, unused, unused, unused);
+    ci->model = (eax >> 4) & 0xF;
+    ci->family = (eax >> 8) & 0xF;
+
+    /*
+     * If the family ID is 15 then the actual family
+     * ID is the sum of the extended family and the
+     * family ID fields.
+     */
+    if (ci->family == 0xF) {
+        ext_family = (eax >> 20) & 0xFF;
+        ci->family += ext_family;
+    }
+
+    /*
+     * If the family has the value of either 6 or 15,
+     * then the extended model number would be used.
+     * Slap them together if this is the case.
+     */
+    if (ci->family == 6 || ci->family == 15) {
+        ext_model = (eax >> 16) & 0xF;
+        ci->model |= (ext_model << 4);
+    }
 }
 
 void
@@ -224,6 +254,7 @@ md_backtrace(void)
     uintptr_t rip;
     off_t off;
     const char *name;
+    char line[256];
 
     __ASMV("mov %%rbp, %0" : "=r" (rbp) :: "memory");
     while (1) {
@@ -236,7 +267,8 @@ md_backtrace(void)
         if (name == NULL)
             name = "???";
 
-        kprintf(OMIT_TIMESTAMP "%p  @ <%s+0x%x>\n", rip, name, off);
+        snprintf(line, sizeof(line), "%p @ <%s+0x%x>\n", rip, name, off);
+        cons_putstr(&g_root_scr, line, strlen(line));
     }
 }
 
@@ -294,6 +326,10 @@ this_cpu(void)
 {
     struct cpu_info *ci;
 
+    if (rdmsr(IA32_GS_BASE) == 0) {
+        return NULL;
+    }
+
     /*
      * This might look crazy but we are just leveraging the "m"
      * constraint to add the offset of the self field within
@@ -375,7 +411,7 @@ cpu_startup(struct cpu_info *ci)
     init_tss(ci);
     try_mitigate_spectre();
 
-    cpu_check_feat(ci);
+    cpu_get_info(ci);
     cpu_enable_smep();
 
     enable_simd();