[ipfire-2.x.git] / src / patches / suse-2.6.27.39 / patches.suse / acpi-dsdt-initrd-v0.9a-2.6.25.patch

From: Eric Piel <piel@localhost.(none)>
Subject: [PATCH 1/1] ACPI: initramfs DSDT override support
Patch-mainline: not yet


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                       |   26 ++++++++++
 drivers/acpi/tables/tbxface.c            |    7 --
 init/initramfs.c                         |   76 +++++++++++++++++++++++++++++++
 7 files changed, 170 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/acpi/initramfs-add-dsdt.sh

--- 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.
--- /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"
+
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -179,6 +179,9 @@ and is between 256 and 4096 characters.
 
 	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"
 
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -301,6 +301,17 @@ 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
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -96,6 +96,11 @@ 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)"
  *
@@ -325,7 +330,7 @@ acpi_os_predefined_override(const struct
 	return AE_OK;
 }
 
-acpi_status
+acpi_status __init
 acpi_os_table_override(struct acpi_table_header * existing_table,
 		       struct acpi_table_header ** new_table)
 {
@@ -338,6 +343,16 @@ acpi_os_table_override(struct acpi_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",
@@ -348,6 +363,15 @@ acpi_os_table_override(struct acpi_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;
--- a/drivers/acpi/tables/tbxface.c
+++ b/drivers/acpi/tables/tbxface.c
@@ -487,7 +487,7 @@ ACPI_EXPORT_SYMBOL(acpi_get_table_by_ind
  *              the RSDT/XSDT.
  *
  ******************************************************************************/
-static acpi_status acpi_tb_load_namespace(void)
+static acpi_status __init acpi_tb_load_namespace(void)
 {
 	acpi_status status;
 	struct acpi_table_header *table;
@@ -612,7 +612,7 @@ static acpi_status acpi_tb_load_namespac
  *
  ******************************************************************************/
 
-acpi_status acpi_load_tables(void)
+acpi_status __init acpi_load_tables(void)
 {
 	acpi_status status;
 
@@ -630,9 +630,6 @@ acpi_status acpi_load_tables(void)
 	return_ACPI_STATUS(status);
 }
 
-ACPI_EXPORT_SYMBOL(acpi_load_tables)
-
-
 /*******************************************************************************
  *
  * FUNCTION:    acpi_install_table_handler
--- 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)
@@ -80,6 +83,12 @@ static __initdata unsigned long body_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)
 {
@@ -113,6 +122,7 @@ static __initdata enum state {
 	SkipIt,
 	GotName,
 	CopyFile,
+	CopyFileMem,
 	GotSymlink,
 	Reset
 } state, next_state;
@@ -257,6 +267,9 @@ 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);
@@ -289,6 +302,40 @@ 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) {
@@ -323,6 +370,7 @@ static __initdata int (*actions[])(void)
 	[SkipIt]	= do_skip,
 	[GotName]	= do_name,
 	[CopyFile]	= do_copy,
+	[CopyFileMem]	= do_copy_mem,
 	[GotSymlink]	= do_symlink,
 	[Reset]		= do_reset,
 };
@@ -560,3 +608,31 @@ static int __init populate_rootfs(void)
 	return 0;
 }
 rootfs_initcall(populate_rootfs);
+
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+struct acpi_table_header * __init 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
Commit	Line	Data
2cb7cef9 BS	1	From: Eric Piel <piel@localhost.(none)>
	2	Subject: [PATCH 1/1] ACPI: initramfs DSDT override support
	3	Patch-mainline: not yet
	4
	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 \| 26 ++++++++++
	30	drivers/acpi/tables/tbxface.c \| 7 --
	31	init/initramfs.c \| 76 +++++++++++++++++++++++++++++++
	32	7 files changed, 170 insertions(+), 8 deletions(-)
	33	create mode 100644 Documentation/acpi/initramfs-add-dsdt.sh
	34
	35	--- a/Documentation/acpi/dsdt-override.txt
	36	+++ b/Documentation/acpi/dsdt-override.txt
	37	@@ -1,7 +1,15 @@
	38	-Linux supports a method of overriding the BIOS DSDT:
	39	+Linux supports two methods of overriding the BIOS DSDT:
	40
	41	CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
	42
	43	-When to use this method is described in detail on the
	44	+CONFIG_ACPI_CUSTOM_DSDT_INITRD adds the image to the initrd.
	45	+
	46	+When to use these methods is described in detail on the
	47	Linux/ACPI home page:
	48	http://www.lesswatts.org/projects/acpi/overridingDSDT.php
	49	+
	50	+Note that if both options are used, the DSDT supplied
	51	+by the INITRD method takes precedence.
	52	+
	53	+Documentation/initramfs-add-dsdt.sh is provided for convenience
	54	+for use with the CONFIG_ACPI_CUSTOM_DSDT_INITRD method.
	55	--- /dev/null
	56	+++ b/Documentation/acpi/initramfs-add-dsdt.sh
	57	@@ -0,0 +1,43 @@
	58	+#!/bin/bash
	59	+# Adds a DSDT file to the initrd (if it's an initramfs)
	60	+# first argument is the name of archive
	61	+# second argument is the name of the file to add
	62	+# The file will be copied as /DSDT.aml
	63	+
	64	+# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
65	+# 20060205: this time it should really work
66	+
67	+# check the arguments
68	+if [ $# -ne 2 ]; then
69	+ program_name=$(basename $0)
70	+ echo "\
71	+$program_name: too few arguments
72	+Usage: $program_name initrd-name.img DSDT-to-add.aml
73	+Adds a DSDT file to an initrd (in initramfs format)
74	+
75	+ initrd-name.img: filename of the initrd in initramfs format
76	+ DSDT-to-add.aml: filename of the DSDT file to add
77	+ " 1>&2
78	+ exit 1
79	+fi
80	+
81	+# we should check it's an initramfs
82	+
83	+tempcpio=$(mktemp -d)
84	+# cleanup on exit, hangup, interrupt, quit, termination
85	+trap 'rm -rf $tempcpio' 0 1 2 3 15
86	+
87	+# extract the archive
88	+gunzip -c "$1" > "$tempcpio"/initramfs.cpio \|\| exit 1
89	+
90	+# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
91	+cp -f "$2" "$tempcpio"/DSDT.aml
92	+
93	+# add the file
94	+cd "$tempcpio"
95	+(echo DSDT.aml \| cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) \|\| exit 1
96	+cd "$OLDPWD"
97	+
98	+# re-compress the archive
99	+gzip -c "$tempcpio"/initramfs.cpio > "$1"
100	+
101	--- a/Documentation/kernel-parameters.txt
102	+++ b/Documentation/kernel-parameters.txt
103	@@ -179,6 +179,9 @@ and is between 256 and 4096 characters.
104
105	acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
106
107	+ acpi_no_initrd_override [KNL,ACPI]
108	+ Disable loading custom ACPI tables from the initramfs
109	+
110	acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
111	Format: To spoof as Windows 98: ="Microsoft Windows"
112
113	--- a/drivers/acpi/Kconfig
114	+++ b/drivers/acpi/Kconfig
115	@@ -301,6 +301,17 @@ config ACPI_CUSTOM_DSDT
116	bool
117	default ACPI_CUSTOM_DSDT_FILE != ""
118
119	+config ACPI_CUSTOM_DSDT_INITRD
120	+ bool "Read Custom DSDT from initramfs"
121	+ depends on BLK_DEV_INITRD
122	+ default n
123	+ help
124	+ This option supports a custom DSDT by optionally loading it from initrd.
125	+ See Documentation/acpi/dsdt-override.txt
126	+
127	+ If you are not using this feature now, but may use it later,
128	+ it is safe to say Y here.
129	+
130	config ACPI_BLACKLIST_YEAR
131	int "Disable ACPI for systems before Jan 1st this year" if X86_32
132	default 0
133	--- a/drivers/acpi/osl.c
134	+++ b/drivers/acpi/osl.c
135	@@ -96,6 +96,11 @@ static DEFINE_SPINLOCK(acpi_res_lock);
136	#define OSI_STRING_LENGTH_MAX 64 /* arbitrary */
137	static char osi_additional_string[OSI_STRING_LENGTH_MAX];
138
139	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
140	+static int acpi_no_initrd_override;
141	+extern struct acpi_table_header *acpi_find_dsdt_initrd(void);
142	+#endif
143	+
144	/*
145	* "Ode to _OSI(Linux)"
146	*
147	@@ -325,7 +330,7 @@ acpi_os_predefined_override(const struct
148	return AE_OK;
149	}
150
151	-acpi_status
152	+acpi_status __init
153	acpi_os_table_override(struct acpi_table_header * existing_table,
154	struct acpi_table_header ** new_table)
155	{
156	@@ -338,6 +343,16 @@ acpi_os_table_override(struct acpi_table
157	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
158	new_table = (struct acpi_table_header )AmlCode;
159	#endif
160	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
161	+ if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
162	+ !acpi_no_initrd_override) {
163	+ struct acpi_table_header *initrd_table;
164	+
165	+ initrd_table = acpi_find_dsdt_initrd();
166	+ if (initrd_table)
167	+ *new_table = initrd_table;
168	+ }
169	+#endif
170	if (*new_table != NULL) {
171	printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
172	"this is unsafe: tainting kernel\n",
173	@@ -348,6 +363,15 @@ acpi_os_table_override(struct acpi_table
174	return AE_OK;
175	}
176
177	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
178	+static int __init acpi_no_initrd_override_setup(char *s)
179	+{
180	+ acpi_no_initrd_override = 1;
181	+ return 1;
182	+}
183	+__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
184	+#endif
185	+
186	static irqreturn_t acpi_irq(int irq, void *dev_id)
187	{
188	u32 handled;
189	--- a/drivers/acpi/tables/tbxface.c
190	+++ b/drivers/acpi/tables/tbxface.c
191	@@ -487,7 +487,7 @@ ACPI_EXPORT_SYMBOL(acpi_get_table_by_ind
192	* the RSDT/XSDT.
193	*
194	******************************************************************************/
195	-static acpi_status acpi_tb_load_namespace(void)
196	+static acpi_status __init acpi_tb_load_namespace(void)
197	{
198	acpi_status status;
199	struct acpi_table_header *table;
200	@@ -612,7 +612,7 @@ static acpi_status acpi_tb_load_namespac
201	*
202	******************************************************************************/
203
204	-acpi_status acpi_load_tables(void)
205	+acpi_status __init acpi_load_tables(void)
206	{
207	acpi_status status;
208
209	@@ -630,9 +630,6 @@ acpi_status acpi_load_tables(void)
210	return_ACPI_STATUS(status);
211	}
212
213	-ACPI_EXPORT_SYMBOL(acpi_load_tables)
214	-
215	-
216	/*******************************************************************************
217	*
218	* FUNCTION: acpi_install_table_handler
219	--- a/init/initramfs.c
220	+++ b/init/initramfs.c
221	@@ -6,6 +6,9 @@
222	#include <linux/delay.h>
223	#include <linux/string.h>
224	#include <linux/syscalls.h>
225	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
226	+#include <acpi/acpi.h>
227	+#endif
228
229	static __initdata char *message;
230	static void __init error(char *x)
231	@@ -80,6 +83,12 @@ static __initdata unsigned long body_len
232	static __initdata uid_t uid;
233	static __initdata gid_t gid;
234	static __initdata unsigned rdev;
235	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
236	+static __initdata char *file_looked_for;
237	+static __initdata struct acpi_table_header *file_mem;
238	+#else
239	+const char *file_looked_for = NULL;
240	+#endif
241
242	static void __init parse_header(char *s)
243	{
244	@@ -113,6 +122,7 @@ static __initdata enum state {
245	SkipIt,
246	GotName,
247	CopyFile,
248	+ CopyFileMem,
249	GotSymlink,
250	Reset
251	} state, next_state;
252	@@ -257,6 +267,9 @@ static int __init do_name(void)
253	free_hash();
254	return 0;
255	}
256	+ if (file_looked_for && S_ISREG(mode) &&
257	+ (strcmp(collected, file_looked_for) == 0))
258	+ state = CopyFileMem;
259	if (dry_run)
260	return 0;
261	clean_path(collected, mode);
262	@@ -289,6 +302,40 @@ static int __init do_name(void)
263	return 0;
264	}
265
266	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
267	+static int __init do_copy_mem(void)
268	+{
269	+ static void file_current; / current position in the memory */
270	+ if (file_mem == NULL) {
271	+ if (body_len < 4) { /* check especially against empty files */
272	+ error("file is less than 4 bytes");
273	+ return 1;
274	+ }
275	+ file_mem = kmalloc(body_len, GFP_ATOMIC);
276	+ if (!file_mem) {
277	+ error("failed to allocate enough memory");
278	+ return 1;
279	+ }
280	+ file_current = file_mem;
281	+ }
282	+ if (count >= body_len) {
283	+ memcpy(file_current, victim, body_len);
284	+ eat(body_len);
285	+ file_looked_for = NULL; /* don't find files with same name */
286	+ state = SkipIt;
287	+ return 0;
288	+ } else {
289	+ memcpy(file_current, victim, count);
290	+ file_current += count;
291	+ body_len -= count;
292	+ eat(count);
293	+ return 1;
294	+ }
295	+}
296	+#else
297	+#define do_copy_mem NULL
298	+#endif
299	+
300	static int __init do_copy(void)
301	{
302	if (count >= body_len) {
303	@@ -323,6 +370,7 @@ static __initdata int (*actions[])(void)
304	[SkipIt] = do_skip,
305	[GotName] = do_name,
306	[CopyFile] = do_copy,
307	+ [CopyFileMem] = do_copy_mem,
308	[GotSymlink] = do_symlink,
309	[Reset] = do_reset,
310	};
311	@@ -560,3 +608,31 @@ static int __init populate_rootfs(void)
312	return 0;
313	}
314	rootfs_initcall(populate_rootfs);
315	+
316	+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
317	+struct acpi_table_header * __init acpi_find_dsdt_initrd(void)
318	+{
319	+ char err, ramfs_dsdt_name = "DSDT.aml";
320	+
321	+ printk(KERN_INFO "ACPI: Checking initramfs for custom DSDT\n");
322	+ file_mem = NULL;
323	+ file_looked_for = ramfs_dsdt_name;
324	+ err = unpack_to_rootfs((char *)initrd_start,
325	+ initrd_end - initrd_start, 1);
326	+ file_looked_for = NULL;
327	+
328	+ if (err) {
329	+ /*
330	+ * Even if reading the DSDT file was successful,
331	+ * we give up if the initramfs cannot be entirely read.
332	+ */
333	+ kfree(file_mem);
334	+ printk(KERN_ERR "ACPI: Aborded because %s.\n", err);
335	+ return NULL;
336	+ }
337	+ if (file_mem)
338	+ printk(KERN_INFO "ACPI: Found DSDT in %s.\n", ramfs_dsdt_name);
339	+
340	+ return file_mem;
341	+}
342	+#endif