kernel26-xen/patches-2.6.25-r1/0157-2.6.25-acpi-dsdt-initrd-0.9a.patch

From de31945e20bc0bd255d0264c5d97a6b24906b30a Mon Sep 17 00:00:00 2001
From: Eric Piel <piel@localhost.(none)>
Date: Wed, 19 Mar 2008 23:00:04 +0100
Subject: [PATCH 1/1] ACPI: initramfs DSDT override support

Permits to load of DSDT (the main ACPI table) from initramfs. In case this
option is selected, the initramfs is parsed at ACPI initialization (very early
boot time) to look for a file DSDT.aml . This aims at allowing users to
override the DSDT without recompiling the kernel. This is done by adding a new
feature to the initramfs parser so that one specific file can be directly
copied into memory.

This is derived from the patch v0.8 from http://gaugusch.at/kernel.shtml but
with kernel inclusion in mind: some clean-up's in the documentation, default
set to No, a kernel parameter to disable it at runtime, and most important, a
different approach for reading the initramfs which avoids using the filesystem
infrastructure.

It also contains a fix for compilation on non-ACPI platforms provided by Rene Rebe.

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
---
 Documentation/acpi/dsdt-override.txt     |   12 ++++-
 Documentation/acpi/initramfs-add-dsdt.sh |   43 +++++++++++++++++
 Documentation/kernel-parameters.txt      |    3 +
 drivers/acpi/Kconfig                     |   11 ++++
 drivers/acpi/osl.c                       |   24 ++++++++++
 init/initramfs.c                         |   76 ++++++++++++++++++++++++++++++
 6 files changed, 167 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/acpi/initramfs-add-dsdt.sh

diff --git a/Documentation/acpi/dsdt-override.txt b/Documentation/acpi/dsdt-override.txt
index febbb1b..5008f25 100644
--- a/Documentation/acpi/dsdt-override.txt
+++ b/Documentation/acpi/dsdt-override.txt
@@ -1,7 +1,15 @@
-Linux supports a method of overriding the BIOS DSDT:
+Linux supports two methods of overriding the BIOS DSDT:
 
 CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
 
-When to use this method is described in detail on the
+CONFIG_ACPI_CUSTOM_DSDT_INITRD adds the image to the initrd.
+
+When to use these methods is described in detail on the
 Linux/ACPI home page:
 http://www.lesswatts.org/projects/acpi/overridingDSDT.php
+
+Note that if both options are used, the DSDT supplied
+by the INITRD method takes precedence.
+
+Documentation/initramfs-add-dsdt.sh is provided for convenience
+for use with the CONFIG_ACPI_CUSTOM_DSDT_INITRD method.
diff --git a/Documentation/acpi/initramfs-add-dsdt.sh b/Documentation/acpi/initramfs-add-dsdt.sh
new file mode 100644
index 0000000..17ef6e8
--- /dev/null
+++ b/Documentation/acpi/initramfs-add-dsdt.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+# Adds a DSDT file to the initrd (if it's an initramfs)
+# first argument is the name of archive
+# second argument is the name of the file to add
+# The file will be copied as /DSDT.aml
+
+# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
+# 20060205: this time it should really work
+
+# check the arguments
+if [ $# -ne 2 ]; then
+	program_name=$(basename $0)
+	echo "\
+$program_name: too few arguments
+Usage: $program_name initrd-name.img DSDT-to-add.aml
+Adds a DSDT file to an initrd (in initramfs format)
+
+  initrd-name.img: filename of the initrd in initramfs format
+  DSDT-to-add.aml: filename of the DSDT file to add
+  " 1>&2
+    exit 1
+fi
+
+# we should check it's an initramfs
+
+tempcpio=$(mktemp -d)
+# cleanup on exit, hangup, interrupt, quit, termination
+trap 'rm -rf $tempcpio' 0 1 2 3 15
+
+# extract the archive
+gunzip -c "$1" > "$tempcpio"/initramfs.cpio || exit 1
+
+# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
+cp -f "$2" "$tempcpio"/DSDT.aml
+
+# add the file
+cd "$tempcpio"
+(echo DSDT.aml | cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) || exit 1
+cd "$OLDPWD"
+
+# re-compress the archive
+gzip -c "$tempcpio"/initramfs.cpio > "$1"
+
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 622f784..49318b9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -177,6 +177,9 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	acpi_no_auto_ssdt	[HW,ACPI] Disable automatic loading of SSDT
 
+	acpi_no_initrd_override	[KNL,ACPI]
+			Disable loading custom ACPI tables from the initramfs
+
 	acpi_os_name=	[HW,ACPI] Tell ACPI BIOS the name of the OS
 			Format: To spoof as Windows 98: ="Microsoft Windows"
 
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index b4f5e85..fbcaa06 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -300,6 +300,17 @@ config ACPI_CUSTOM_DSDT
 	bool
 	default ACPI_CUSTOM_DSDT_FILE != ""
 
+config ACPI_CUSTOM_DSDT_INITRD
+	bool "Read Custom DSDT from initramfs"
+	depends on BLK_DEV_INITRD
+	default n
+	help
+	  This option supports a custom DSDT by optionally loading it from initrd.
+	  See Documentation/acpi/dsdt-override.txt
+
+	  If you are not using this feature now, but may use it later,
+	  it is safe to say Y here.
+
 config ACPI_BLACKLIST_YEAR
 	int "Disable ACPI for systems before Jan 1st this year" if X86_32
 	default 0
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index a697fb6..8fa630f 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -91,6 +91,11 @@ static DEFINE_SPINLOCK(acpi_res_lock);
 #define	OSI_STRING_LENGTH_MAX 64	/* arbitrary */
 static char osi_additional_string[OSI_STRING_LENGTH_MAX];
 
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+static int acpi_no_initrd_override;
+extern struct acpi_table_header *acpi_find_dsdt_initrd(void);
+#endif
+
 /*
  * "Ode to _OSI(Linux)"
  *
@@ -333,6 +338,16 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
 		*new_table = (struct acpi_table_header *)AmlCode;
 #endif
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+	if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
+	    !acpi_no_initrd_override) {
+		struct acpi_table_header *initrd_table;
+
+		initrd_table = acpi_find_dsdt_initrd();
+		if (initrd_table)
+			*new_table = initrd_table;
+	}
+#endif
 	if (*new_table != NULL) {
 		printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
 			   "this is unsafe: tainting kernel\n",
@@ -343,6 +358,15 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
 	return AE_OK;
 }
 
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+static int __init acpi_no_initrd_override_setup(char *s)
+{
+	acpi_no_initrd_override = 1;
+	return 1;
+}
+__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
+#endif
+
 static irqreturn_t acpi_irq(int irq, void *dev_id)
 {
 	u32 handled;
diff --git a/init/initramfs.c b/init/initramfs.c
index d53fee8..495380c 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -6,6 +6,9 @@
 #include <linux/delay.h>
 #include <linux/string.h>
 #include <linux/syscalls.h>
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+#include <acpi/acpi.h>
+#endif
 
 static __initdata char *message;
 static void __init error(char *x)
@@ -90,6 +91,12 @@ static __initdata unsigned long body_len, name_len;
 static __initdata uid_t uid;
 static __initdata gid_t gid;
 static __initdata unsigned rdev;
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+static __initdata char *file_looked_for;
+static __initdata struct acpi_table_header *file_mem;
+#else
+const char *file_looked_for = NULL;
+#endif
 
 static void __init parse_header(char *s)
 {
@@ -123,6 +130,7 @@ static __initdata enum state {
 	SkipIt,
 	GotName,
 	CopyFile,
+	CopyFileMem,
 	GotSymlink,
 	Reset
 } state, next_state;
@@ -267,6 +275,9 @@ static int __init do_name(void)
 		free_hash();
 		return 0;
 	}
+	if (file_looked_for && S_ISREG(mode) &&
+		(strcmp(collected, file_looked_for) == 0))
+		state = CopyFileMem;
 	if (dry_run)
 		return 0;
 	clean_path(collected, mode);
@@ -299,6 +310,40 @@ static int __init do_name(void)
 	return 0;
 }
 
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+static int __init do_copy_mem(void)
+{
+	static void *file_current; /* current position in the memory */
+	if (file_mem == NULL) {
+		if (body_len < 4) { /* check especially against empty files */
+			error("file is less than 4 bytes");
+			return 1;
+		}
+		file_mem = kmalloc(body_len, GFP_ATOMIC);
+		if (!file_mem) {
+			error("failed to allocate enough memory");
+			return 1;
+		}
+		file_current = file_mem;
+	}
+	if (count >= body_len) {
+		memcpy(file_current, victim, body_len);
+		eat(body_len);
+		file_looked_for = NULL; /* don't find files with same name */
+		state = SkipIt;
+		return 0;
+	} else {
+		memcpy(file_current, victim, count);
+		file_current += count;
+		body_len -= count;
+		eat(count);
+		return 1;
+	}
+}
+#else
+#define do_copy_mem NULL
+#endif
+
 static int __init do_copy(void)
 {
 	if (count >= body_len) {
@@ -333,6 +378,7 @@ static __initdata int (*actions[])(void) = {
 	[SkipIt]	= do_skip,
 	[GotName]	= do_name,
 	[CopyFile]	= do_copy,
+	[CopyFileMem]	= do_copy_mem,
 	[GotSymlink]	= do_symlink,
 	[Reset]		= do_reset,
 };
@@ -578,3 +624,31 @@ static int __init populate_rootfs(void)
 	return 0;
 }
 rootfs_initcall(populate_rootfs);
+
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+struct acpi_table_header *acpi_find_dsdt_initrd(void)
+{
+	char *err, *ramfs_dsdt_name = "DSDT.aml";
+
+	printk(KERN_INFO "ACPI: Checking initramfs for custom DSDT\n");
+	file_mem = NULL;
+	file_looked_for = ramfs_dsdt_name;
+	err = unpack_to_rootfs((char *)initrd_start,
+			initrd_end - initrd_start, 1);
+	file_looked_for = NULL;
+
+	if (err) {
+		/*
+		 * Even if reading the DSDT file was successful,
+		 * we give up if the initramfs cannot be entirely read.
+		 */
+		kfree(file_mem);
+		printk(KERN_ERR "ACPI: Aborded because %s.\n", err);
+		return NULL;
+	}
+	if (file_mem)
+		printk(KERN_INFO "ACPI: Found DSDT in %s.\n", ramfs_dsdt_name);
+
+	return file_mem;
+}
+#endif
-- 
1.5.4.3

1	niro	606	From de31945e20bc0bd255d0264c5d97a6b24906b30a Mon Sep 17 00:00:00 2001
2			From: Eric Piel <piel@localhost.(none)>
3			Date: Wed, 19 Mar 2008 23:00:04 +0100
4			Subject: [PATCH 1/1] ACPI: initramfs DSDT override support
5
6			Permits to load of DSDT (the main ACPI table) from initramfs. In case this
7			option is selected, the initramfs is parsed at ACPI initialization (very early
8			boot time) to look for a file DSDT.aml . This aims at allowing users to
9			override the DSDT without recompiling the kernel. This is done by adding a new
10			feature to the initramfs parser so that one specific file can be directly
11			copied into memory.
12
13			This is derived from the patch v0.8 from http://gaugusch.at/kernel.shtml but
14			with kernel inclusion in mind: some clean-up's in the documentation, default
15			set to No, a kernel parameter to disable it at runtime, and most important, a
16			different approach for reading the initramfs which avoids using the filesystem
17			infrastructure.
18
19			It also contains a fix for compilation on non-ACPI platforms provided by Rene Rebe.
20
21			Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
22			Signed-off-by: Thomas Renninger <trenn@suse.de>
23			Signed-off-by: Len Brown <len.brown@intel.com>
24			---
25			Documentation/acpi/dsdt-override.txt \| 12 ++++-
26			Documentation/acpi/initramfs-add-dsdt.sh \| 43 +++++++++++++++++
27			Documentation/kernel-parameters.txt \| 3 +
28			drivers/acpi/Kconfig \| 11 ++++
29			drivers/acpi/osl.c \| 24 ++++++++++
30			init/initramfs.c \| 76 ++++++++++++++++++++++++++++++
31			6 files changed, 167 insertions(+), 2 deletions(-)
32			create mode 100644 Documentation/acpi/initramfs-add-dsdt.sh
33
34			diff --git a/Documentation/acpi/dsdt-override.txt b/Documentation/acpi/dsdt-override.txt
35			index febbb1b..5008f25 100644
36			--- a/Documentation/acpi/dsdt-override.txt
37			+++ b/Documentation/acpi/dsdt-override.txt
38			@@ -1,7 +1,15 @@
39			-Linux supports a method of overriding the BIOS DSDT:
40			+Linux supports two methods of overriding the BIOS DSDT:
41
42			CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
43
44			-When to use this method is described in detail on the
45			+CONFIG_ACPI_CUSTOM_DSDT_INITRD adds the image to the initrd.
46			+
47			+When to use these methods is described in detail on the
48			Linux/ACPI home page:
49			http://www.lesswatts.org/projects/acpi/overridingDSDT.php
50			+
51			+Note that if both options are used, the DSDT supplied
52			+by the INITRD method takes precedence.
53			+
54			+Documentation/initramfs-add-dsdt.sh is provided for convenience
55			+for use with the CONFIG_ACPI_CUSTOM_DSDT_INITRD method.
56			diff --git a/Documentation/acpi/initramfs-add-dsdt.sh b/Documentation/acpi/initramfs-add-dsdt.sh
57			new file mode 100644
58			index 0000000..17ef6e8
59			--- /dev/null
60			+++ b/Documentation/acpi/initramfs-add-dsdt.sh
61			@@ -0,0 +1,43 @@
62			+#!/bin/bash
63			+# Adds a DSDT file to the initrd (if it's an initramfs)
64			+# first argument is the name of archive
65			+# second argument is the name of the file to add
66			+# The file will be copied as /DSDT.aml
67			+
68			+# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
69			+# 20060205: this time it should really work
70			+
71			+# check the arguments
72			+if [ $# -ne 2 ]; then
73			+ program_name=$(basename $0)
74			+ echo "\
75			+$program_name: too few arguments
76			+Usage: $program_name initrd-name.img DSDT-to-add.aml
77			+Adds a DSDT file to an initrd (in initramfs format)
78			+
79			+ initrd-name.img: filename of the initrd in initramfs format
80			+ DSDT-to-add.aml: filename of the DSDT file to add
81			+ " 1>&2
82			+ exit 1
83			+fi
84			+
85			+# we should check it's an initramfs
86			+
87			+tempcpio=$(mktemp -d)
88			+# cleanup on exit, hangup, interrupt, quit, termination
89			+trap 'rm -rf $tempcpio' 0 1 2 3 15
90			+
91			+# extract the archive
92			+gunzip -c "$1" > "$tempcpio"/initramfs.cpio \|\| exit 1
93			+
94			+# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
95			+cp -f "$2" "$tempcpio"/DSDT.aml
96			+
97			+# add the file
98			+cd "$tempcpio"
99			+(echo DSDT.aml \| cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) \|\| exit 1
100			+cd "$OLDPWD"
101			+
102			+# re-compress the archive
103			+gzip -c "$tempcpio"/initramfs.cpio > "$1"
104			+
105			diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
106			index 622f784..49318b9 100644
107			--- a/Documentation/kernel-parameters.txt
108			+++ b/Documentation/kernel-parameters.txt
109			@@ -177,6 +177,9 @@ and is between 256 and 4096 characters. It is defined in the file
110
111			acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
112
113			+ acpi_no_initrd_override [KNL,ACPI]
114			+ Disable loading custom ACPI tables from the initramfs
115			+
116			acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
117			Format: To spoof as Windows 98: ="Microsoft Windows"
118
119			diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
120			index b4f5e85..fbcaa06 100644
121			--- a/drivers/acpi/Kconfig
122			+++ b/drivers/acpi/Kconfig
123			@@ -300,6 +300,17 @@ config ACPI_CUSTOM_DSDT
124			bool
125			default ACPI_CUSTOM_DSDT_FILE != ""
126
127			+config ACPI_CUSTOM_DSDT_INITRD
128			+ bool "Read Custom DSDT from initramfs"
129			+ depends on BLK_DEV_INITRD
130			+ default n
131			+ help
132			+ This option supports a custom DSDT by optionally loading it from initrd.
133			+ See Documentation/acpi/dsdt-override.txt
134			+
135			+ If you are not using this feature now, but may use it later,
136			+ it is safe to say Y here.
137			+
138			config ACPI_BLACKLIST_YEAR
139			int "Disable ACPI for systems before Jan 1st this year" if X86_32
140			default 0
141			diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
142			index a697fb6..8fa630f 100644
143			--- a/drivers/acpi/osl.c
144			+++ b/drivers/acpi/osl.c
145			@@ -91,6 +91,11 @@ static DEFINE_SPINLOCK(acpi_res_lock);
146			#define OSI_STRING_LENGTH_MAX 64 /* arbitrary */
147			static char osi_additional_string[OSI_STRING_LENGTH_MAX];
148
149			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
150			+static int acpi_no_initrd_override;
151			+extern struct acpi_table_header *acpi_find_dsdt_initrd(void);
152			+#endif
153			+
154			/*
155			* "Ode to _OSI(Linux)"
156			*
157			@@ -333,6 +338,16 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
158			if (strncmp(existing_table->signature, "DSDT", 4) == 0)
159			new_table = (struct acpi_table_header )AmlCode;
160			#endif
161			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
162			+ if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
163			+ !acpi_no_initrd_override) {
164			+ struct acpi_table_header *initrd_table;
165			+
166			+ initrd_table = acpi_find_dsdt_initrd();
167			+ if (initrd_table)
168			+ *new_table = initrd_table;
169			+ }
170			+#endif
171			if (*new_table != NULL) {
172			printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
173			"this is unsafe: tainting kernel\n",
174			@@ -343,6 +358,15 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
175			return AE_OK;
176			}
177
178			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
179			+static int __init acpi_no_initrd_override_setup(char *s)
180			+{
181			+ acpi_no_initrd_override = 1;
182			+ return 1;
183			+}
184			+__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
185			+#endif
186			+
187			static irqreturn_t acpi_irq(int irq, void *dev_id)
188			{
189			u32 handled;
190			diff --git a/init/initramfs.c b/init/initramfs.c
191			index d53fee8..495380c 100644
192			--- a/init/initramfs.c
193			+++ b/init/initramfs.c
194			@@ -6,6 +6,9 @@
195			#include <linux/delay.h>
196			#include <linux/string.h>
197			#include <linux/syscalls.h>
198			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
199			+#include <acpi/acpi.h>
200			+#endif
201
202			static __initdata char *message;
203			static void __init error(char *x)
204			@@ -90,6 +91,12 @@ static __initdata unsigned long body_len, name_len;
205			static __initdata uid_t uid;
206			static __initdata gid_t gid;
207			static __initdata unsigned rdev;
208			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
209			+static __initdata char *file_looked_for;
210			+static __initdata struct acpi_table_header *file_mem;
211			+#else
212			+const char *file_looked_for = NULL;
213			+#endif
214
215			static void __init parse_header(char *s)
216			{
217			@@ -123,6 +130,7 @@ static __initdata enum state {
218			SkipIt,
219			GotName,
220			CopyFile,
221			+ CopyFileMem,
222			GotSymlink,
223			Reset
224			} state, next_state;
225			@@ -267,6 +275,9 @@ static int __init do_name(void)
226			free_hash();
227			return 0;
228			}
229			+ if (file_looked_for && S_ISREG(mode) &&
230			+ (strcmp(collected, file_looked_for) == 0))
231			+ state = CopyFileMem;
232			if (dry_run)
233			return 0;
234			clean_path(collected, mode);
235			@@ -299,6 +310,40 @@ static int __init do_name(void)
236			return 0;
237			}
238
239			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
240			+static int __init do_copy_mem(void)
241			+{
242			+ static void file_current; / current position in the memory */
243			+ if (file_mem == NULL) {
244			+ if (body_len < 4) { /* check especially against empty files */
245			+ error("file is less than 4 bytes");
246			+ return 1;
247			+ }
248			+ file_mem = kmalloc(body_len, GFP_ATOMIC);
249			+ if (!file_mem) {
250			+ error("failed to allocate enough memory");
251			+ return 1;
252			+ }
253			+ file_current = file_mem;
254			+ }
255			+ if (count >= body_len) {
256			+ memcpy(file_current, victim, body_len);
257			+ eat(body_len);
258			+ file_looked_for = NULL; /* don't find files with same name */
259			+ state = SkipIt;
260			+ return 0;
261			+ } else {
262			+ memcpy(file_current, victim, count);
263			+ file_current += count;
264			+ body_len -= count;
265			+ eat(count);
266			+ return 1;
267			+ }
268			+}
269			+#else
270			+#define do_copy_mem NULL
271			+#endif
272			+
273			static int __init do_copy(void)
274			{
275			if (count >= body_len) {
276			@@ -333,6 +378,7 @@ static __initdata int (*actions[])(void) = {
277			[SkipIt] = do_skip,
278			[GotName] = do_name,
279			[CopyFile] = do_copy,
280			+ [CopyFileMem] = do_copy_mem,
281			[GotSymlink] = do_symlink,
282			[Reset] = do_reset,
283			};
284			@@ -578,3 +624,31 @@ static int __init populate_rootfs(void)
285			return 0;
286			}
287			rootfs_initcall(populate_rootfs);
288			+
289			+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
290			+struct acpi_table_header *acpi_find_dsdt_initrd(void)
291			+{
292			+ char err, ramfs_dsdt_name = "DSDT.aml";
293			+
294			+ printk(KERN_INFO "ACPI: Checking initramfs for custom DSDT\n");
295			+ file_mem = NULL;
296			+ file_looked_for = ramfs_dsdt_name;
297			+ err = unpack_to_rootfs((char *)initrd_start,
298			+ initrd_end - initrd_start, 1);
299			+ file_looked_for = NULL;
300			+
301			+ if (err) {
302			+ /*
303			+ * Even if reading the DSDT file was successful,
304			+ * we give up if the initramfs cannot be entirely read.
305			+ */
306			+ kfree(file_mem);
307			+ printk(KERN_ERR "ACPI: Aborded because %s.\n", err);
308			+ return NULL;
309			+ }
310			+ if (file_mem)
311			+ printk(KERN_INFO "ACPI: Found DSDT in %s.\n", ramfs_dsdt_name);
312			+
313			+ return file_mem;
314			+}
315			+#endif
316			--
317			1.5.4.3
318