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/* ----------------------------------------------------------------------- *
*
* 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;
}
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