x86 setup: print missing CPU features in cleartext

Instead of obscure numbers, print the list of missing CPU features in
cleartext.  To conserve space, use a host program (mkcpustr.c) to
produce a compact list of mandatory features only.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 49 insertions, 0 deletions

diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c
new file mode 100644
index 000000000000..bbe76953bae9
--- /dev/null
+++ b/arch/x86/boot/mkcpustr.c
@@ -0,0 +1,49 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 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 or (at your
+ *   option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * This is a host program to preprocess the CPU strings into a
+ * compact format suitable for the setup code.
+ */
+
+#include <stdio.h>
+
+#include "../kernel/cpu/feature_names.c"
+
+#if NCAPFLAGS > 8
+# error "Need to adjust the boot code handling of CPUID strings"
+#endif
+
+int main(void)
+{
+        int i;
+        const char *str;
+
+        printf("static const char x86_cap_strs[] = \n");
+
+        for (i = 0; i < NCAPINTS*32; i++) {
+                str = x86_cap_flags[i];
+
+                if (i == NCAPINTS*32-1) {
+                        /* The last entry must be unconditional; this
+                           also consumes the compiler-added null character */
+                        if (!str)
+                                str = "";
+                        printf("\t\"\\x%02x\"\"%s\"\n", i, str);
+                } else if (str) {
+                        printf("#if REQUIRED_MASK%d & (1 << %d)\n"
+                               "\t\"\\x%02x\"\"%s\\0\"\n"
+                               "#endif\n",
+                               i >> 5, i & 31, i, str);
+                }
+        }
+        printf("\t;\n");
+        return 0;
+}