x86 boot : export boot_params via debugfs for debugging
This patch export the boot parameters via debugfs for debugging.
The files added are as follow:
boot_params/data : binary file for struct boot_params
boot_params/version : boot protocol version
This patch is based on 2.6.24-rc5-mm1 and has been tested on i386 and
x86_64 platform.
This patch is based on the Peter Anvin's proposal.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index b40bed4..3d23ccd 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -16,7 +16,7 @@
obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o
obj-$(CONFIG_X86_64) += syscall_64.o vsyscall_64.o setup64.o
obj-y += pci-dma_$(BITS).o bootflag.o e820_$(BITS).o
-obj-y += quirks.o i8237.o topology.o
+obj-y += quirks.o i8237.o topology.o kdebugfs.o
obj-y += alternative.o i8253.o
obj-$(CONFIG_X86_64) += pci-nommu_64.o bugs_64.o
obj-y += tsc_$(BITS).o io_delay.o rtc.o
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
new file mode 100644
index 0000000..7335430
--- /dev/null
+++ b/arch/x86/kernel/kdebugfs.c
@@ -0,0 +1,65 @@
+/*
+ * Architecture specific debugfs files
+ *
+ * Copyright (C) 2007, Intel Corp.
+ * Huang Ying <ying.huang@intel.com>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+
+#include <asm/setup.h>
+
+#ifdef CONFIG_DEBUG_BOOT_PARAMS
+static struct debugfs_blob_wrapper boot_params_blob = {
+ .data = &boot_params,
+ .size = sizeof(boot_params),
+};
+
+static int __init boot_params_kdebugfs_init(void)
+{
+ int error;
+ struct dentry *dbp, *version, *data;
+
+ dbp = debugfs_create_dir("boot_params", NULL);
+ if (!dbp) {
+ error = -ENOMEM;
+ goto err_return;
+ }
+ version = debugfs_create_x16("version", S_IRUGO, dbp,
+ &boot_params.hdr.version);
+ if (!version) {
+ error = -ENOMEM;
+ goto err_dir;
+ }
+ data = debugfs_create_blob("data", S_IRUGO, dbp,
+ &boot_params_blob);
+ if (!data) {
+ error = -ENOMEM;
+ goto err_version;
+ }
+ return 0;
+err_version:
+ debugfs_remove(version);
+err_dir:
+ debugfs_remove(dbp);
+err_return:
+ return error;
+}
+#endif
+
+static int __init arch_kdebugfs_init(void)
+{
+ int error = 0;
+
+#ifdef CONFIG_DEBUG_BOOT_PARAMS
+ error = boot_params_kdebugfs_init();
+#endif
+
+ return error;
+}
+
+arch_initcall(arch_kdebugfs_init);
diff --git a/arch/x86/kernel/setup64.c b/arch/x86/kernel/setup64.c
index 3b0ffa3..8fa0de8 100644
--- a/arch/x86/kernel/setup64.c
+++ b/arch/x86/kernel/setup64.c
@@ -24,7 +24,11 @@
#include <asm/sections.h>
#include <asm/setup.h>
+#ifndef CONFIG_DEBUG_BOOT_PARAMS
struct boot_params __initdata boot_params;
+#else
+struct boot_params boot_params;
+#endif
cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 704550f..3bce4af 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -194,7 +194,11 @@
static char __initdata command_line[COMMAND_LINE_SIZE];
+#ifndef CONFIG_DEBUG_BOOT_PARAMS
struct boot_params __initdata boot_params;
+#else
+struct boot_params boot_params;
+#endif
#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
struct edd edd;