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Commit f0be6c6a authored by H. Peter Anvin's avatar H. Peter Anvin Committed by Ingo Molnar
Browse files

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: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent fa1408e4

arch/x86/boot/Makefile

+12 −4
Original line number Diff line number Diff line
@@ -43,9 +43,17 @@ setup-y += video-vesa.o 
setup-y		+= video-bios.o



targets		+= $(setup-y)

hostprogs-y	:= tools/build

hostprogs-y	:= mkcpustr tools/build



HOSTCFLAGS_build.o := $(LINUXINCLUDE)

HOST_EXTRACFLAGS += $(LINUXINCLUDE)



$(obj)/cpu.o: $(obj)/cpustr.h



quiet_cmd_cpustr = CPUSTR  $@

      cmd_cpustr = $(obj)/mkcpustr > $@

targets		+= cpustr.h

$(obj)/cpustr.h: $(obj)/mkcpustr FORCE

	$(call if_changed,cpustr)



# ---------------------------------------------------------------------------

arch/x86/boot/cpu.c

+21 −5
Original line number Diff line number Diff line 
/* -*- linux-c -*- ------------------------------------------------------- *

 *

 *   Copyright (C) 1991, 1992 Linus Torvalds

 *   Copyright 2007 rPath, Inc. - All Rights Reserved

 *   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.
@@ -9,7 +9,7 @@ 
 * ----------------------------------------------------------------------- */



/*

 * arch/i386/boot/cpu.c

 * arch/x86/boot/cpu.c

 *

 * Check for obligatory CPU features and abort if the features are not

 * present.
@@ -19,6 +19,8 @@ 
#include "bitops.h"

#include <asm/cpufeature.h>



#include "cpustr.h"



static char *cpu_name(int level)

{

	static char buf[6];
@@ -35,6 +37,7 @@ int validate_cpu(void) 
{

	u32 *err_flags;

	int cpu_level, req_level;

	const unsigned char *msg_strs;



	check_cpu(&cpu_level, &req_level, &err_flags);
@@ -51,13 +54,26 @@ int validate_cpu(void) 
		puts("This kernel requires the following features "

		     "not present on the CPU:\n");



		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 (e & 1)

				int n = (i << 5)+j;

				if (*msg_strs < n) {

					/* Skip to the next string */

					do {

						msg_strs++;

					} while (*msg_strs);

					msg_strs++;

				}

				if (e & 1) {

					if (*msg_strs == n && msg_strs[1])

						printf("%s ", msg_strs+1);

					else

						printf("%d:%d ", i, j);



				}

				e >>= 1;

			}

		}

arch/x86/boot/mkcpustr.c

0 → 100644
+49 −0
Original line number Diff line number Diff line 
/* ----------------------------------------------------------------------- *

 *

 *   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;

}