v4.19.13 snapshot.
diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c
new file mode 100644
index 0000000..26240dd
--- /dev/null
+++ b/arch/x86/boot/cpu.c
@@ -0,0 +1,101 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright 2007-2008 rPath, Inc. - All Rights Reserved
+ *
+ * This file is part of the Linux kernel, and is made available under
+ * the terms of the GNU General Public License version 2.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * arch/x86/boot/cpu.c
+ *
+ * Check for obligatory CPU features and abort if the features are not
+ * present.
+ */
+
+#include "boot.h"
+#ifdef CONFIG_X86_FEATURE_NAMES
+#include "cpustr.h"
+#endif
+
+static char *cpu_name(int level)
+{
+ static char buf[6];
+
+ if (level == 64) {
+ return "x86-64";
+ } else {
+ if (level == 15)
+ level = 6;
+ sprintf(buf, "i%d86", level);
+ return buf;
+ }
+}
+
+static void show_cap_strs(u32 *err_flags)
+{
+ int i, j;
+#ifdef CONFIG_X86_FEATURE_NAMES
+ const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs;
+ for (i = 0; i < NCAPINTS; i++) {
+ u32 e = err_flags[i];
+ for (j = 0; j < 32; j++) {
+ if (msg_strs[0] < i ||
+ (msg_strs[0] == i && msg_strs[1] < j)) {
+ /* Skip to the next string */
+ msg_strs += 2;
+ while (*msg_strs++)
+ ;
+ }
+ if (e & 1) {
+ if (msg_strs[0] == i &&
+ msg_strs[1] == j &&
+ msg_strs[2])
+ printf("%s ", msg_strs+2);
+ else
+ printf("%d:%d ", i, j);
+ }
+ e >>= 1;
+ }
+ }
+#else
+ for (i = 0; i < NCAPINTS; i++) {
+ u32 e = err_flags[i];
+ for (j = 0; j < 32; j++) {
+ if (e & 1)
+ printf("%d:%d ", i, j);
+ e >>= 1;
+ }
+ }
+#endif
+}
+
+int validate_cpu(void)
+{
+ u32 *err_flags;
+ int cpu_level, req_level;
+
+ check_cpu(&cpu_level, &req_level, &err_flags);
+
+ if (cpu_level < req_level) {
+ printf("This kernel requires an %s CPU, ",
+ cpu_name(req_level));
+ printf("but only detected an %s CPU.\n",
+ cpu_name(cpu_level));
+ return -1;
+ }
+
+ if (err_flags) {
+ puts("This kernel requires the following features "
+ "not present on the CPU:\n");
+ show_cap_strs(err_flags);
+ putchar('\n');
+ return -1;
+ } else if (check_knl_erratum()) {
+ return -1;
+ } else {
+ return 0;
+ }
+}