1 files changed, 125 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/modules/ifcpu64.c b/contrib/syslinux-4.02/com32/modules/ifcpu64.c
new file mode 100644
index 0000000..e123922
--- /dev/null
+++ b/contrib/syslinux-4.02/com32/modules/ifcpu64.c
@@ -0,0 +1,125 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2008 H. Peter Anvin - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ *   Boston MA 02110-1301, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * ifcpu64.c
+ *
+ * Run one command if the CPU has 64-bit support, and another if it doesn't.
+ * Eventually this and other features should get folded into some kind
+ * of scripting engine.
+ *
+ * Usage:
+ *
+ *    label boot_kernel
+ *        com32 ifcpu64.c32
+ *        append boot_kernel_64 [-- boot_kernel_32pae] -- boot_kernel_32
+ *    label boot_kernel_32
+ *        kernel vmlinuz_32
+ *        append ...
+ *    label boot_kernel_64
+ *        kernel vmlinuz_64
+ *        append ...
+ */
+
+#include <alloca.h>
+#include <stdlib.h>
+#include <string.h>
+#include <cpuid.h>
+#include <syslinux/boot.h>
+
+static bool __constfunc cpu_has_cpuid(void)
+{
+    return cpu_has_eflag(X86_EFLAGS_ID);
+}
+
+static bool __constfunc cpu_has_level(uint32_t level)
+{
+    uint32_t group;
+    uint32_t limit;
+
+    if (!cpu_has_cpuid())
+	return false;
+
+    group = level & 0xffff0000;
+    limit = cpuid_eax(group);
+
+    if ((limit & 0xffff0000) != group)
+	return false;
+
+    if (level > limit)
+	return false;
+
+    return true;
+}
+
+/* This only supports feature groups 0 and 1, corresponding to the
+   Intel and AMD EDX bit vectors.  We can add more later if need be. */
+static bool __constfunc cpu_has_feature(int x)
+{
+    uint32_t level = ((x & 1) << 31) | 1;
+
+    return cpu_has_level(level) && ((cpuid_edx(level) >> (x & 31) & 1));
+}
+
+/* XXX: this really should be librarized */
+static void boot_args(char **args)
+{
+    int len = 0, a = 0;
+    char **pp;
+    const char *p;
+    char c, *q, *str;
+
+    for (pp = args; *pp; pp++)
+	len += strlen(*pp) + 1;
+
+    q = str = alloca(len);
+    for (pp = args; *pp; pp++) {
+	p = *pp;
+	while ((c = *p++))
+	    *q++ = c;
+	*q++ = ' ';
+	a = 1;
+    }
+    q -= a;
+    *q = '\0';
+
+    if (!str[0])
+	syslinux_run_default();
+    else
+	syslinux_run_command(str);
+}
+
+int main(int argc, char *argv[])
+{
+    char **args[3];
+    int i;
+    int n;
+
+    args[0] = &argv[1];
+    n = 1;
+    for (i = 1; i < argc; i++) {
+	if (!strcmp(argv[i], "--")) {
+	    argv[i] = NULL;
+	    args[n++] = &argv[i + 1];
+	}
+	if (n >= 3)
+	    break;
+    }
+    while (n < 3) {
+	args[n] = args[n - 1];
+	n++;
+    }
+
+    boot_args(cpu_has_feature(X86_FEATURE_LM) ? args[0] :
+	      cpu_has_feature(X86_FEATURE_PAE) ? args[1] : args[2]);
+    return -1;
+}