+++ /dev/null
-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
projects / people / teissler / ipfire-2.x.git / blobdiff