Magellan Linux

  • Back to homepage
    • /[pkg-src]/trunk/kernel26-magellan/patches-2.6.29-r8/0157-2.6.29-acpi-dsdt-initrd-0.9c.patch

    Contents of /trunk/kernel26-magellan/patches-2.6.29-r8/0157-2.6.29-acpi-dsdt-initrd-0.9c.patch

    Parent Directory Parent Directory | Revision Log Revision Log

    Revision 1114 - (show annotations) (download)
    Sun Aug 22 17:59:15 2010 UTC (13 years, 8 months ago) by niro
    File size: 9992 byte(s) 
    -added
    1 ACPI: initramfs DSDT override support
    2
    3 Permits to load of DSDT (the main ACPI table) from initramfs. In case this
    4 option is selected, the initramfs is parsed at ACPI initialization (very early
    5 boot time) to look for a file called "DSDT.aml". This aims at allowing users to
    6 override the DSDT without recompiling the kernel.
    7
    8 Version 0.9 uses a different approach for reading the initramfs which avoids
    9 using the filesystem infrastructure. It leverages the initramfs unpack code to find
    10 and unpack the DSDT directly into the memory.
    11
    12 v0.9a: Fix compilation on non-ACPI platforms by René Rebe <rene@exactcode.de>
    13 v0.9b: Declare more functions __init by Jan Beulich <jbeulich@novell.com>
    14 v0.9c: Allow root to be / instead of nothing, bug reported by Robert Hampovcan
    15
    16 Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
    17 ---
    18 Documentation/acpi/dsdt-override.txt | 12 +++-
    19 Documentation/acpi/initramfs-add-dsdt.sh | 43 ++++++++++++++
    20 Documentation/kernel-parameters.txt | 3 +
    21 drivers/acpi/Kconfig | 11 ++++
    22 drivers/acpi/osl.c | 24 ++++++++
    23 init/initramfs.c | 89 ++++++++++++++++++++++++++++++
    24 6 files changed, 180 insertions(+), 2 deletions(-)
    25 create mode 100644 Documentation/acpi/initramfs-add-dsdt.sh
    26
    27 diff --git a/Documentation/acpi/dsdt-override.txt b/Documentation/acpi/dsdt-override.txt
    28 index febbb1b..5008f25 100644
    29 --- a/Documentation/acpi/dsdt-override.txt
    30 +++ b/Documentation/acpi/dsdt-override.txt
    31 @@ -1,7 +1,15 @@
    32 -Linux supports a method of overriding the BIOS DSDT:
    33 +Linux supports two methods of overriding the BIOS DSDT:
    34
    35 CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
    36
    37 -When to use this method is described in detail on the
    38 +CONFIG_ACPI_CUSTOM_DSDT_INITRD adds the image to the initrd.
    39 +
    40 +When to use these methods is described in detail on the
    41 Linux/ACPI home page:
    42 http://www.lesswatts.org/projects/acpi/overridingDSDT.php
    43 +
    44 +Note that if both options are used, the DSDT supplied
    45 +by the INITRD method takes precedence.
    46 +
    47 +Documentation/initramfs-add-dsdt.sh is provided for convenience
    48 +for use with the CONFIG_ACPI_CUSTOM_DSDT_INITRD method.
    49 diff --git a/Documentation/acpi/initramfs-add-dsdt.sh b/Documentation/acpi/initramfs-add-dsdt.sh
    50 new file mode 100644
    51 index 0000000..17ef6e8
    52 --- /dev/null
    53 +++ b/Documentation/acpi/initramfs-add-dsdt.sh
    54 @@ -0,0 +1,43 @@
    55 +#!/bin/bash
    56 +# Adds a DSDT file to the initrd (if it's an initramfs)
    57 +# first argument is the name of archive
    58 +# second argument is the name of the file to add
    59 +# The file will be copied as /DSDT.aml
    60 +
    61 +# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
    62 +# 20060205: this time it should really work
    63 +
    64 +# check the arguments
    65 +if [ $# -ne 2 ]; then
    66 + program_name=$(basename $0)
    67 + echo "\
    68 +$program_name: too few arguments
    69 +Usage: $program_name initrd-name.img DSDT-to-add.aml
    70 +Adds a DSDT file to an initrd (in initramfs format)
    71 +
    72 + initrd-name.img: filename of the initrd in initramfs format
    73 + DSDT-to-add.aml: filename of the DSDT file to add
    74 + " 1>&2
    75 + exit 1
    76 +fi
    77 +
    78 +# we should check it's an initramfs
    79 +
    80 +tempcpio=$(mktemp -d)
    81 +# cleanup on exit, hangup, interrupt, quit, termination
    82 +trap 'rm -rf $tempcpio' 0 1 2 3 15
    83 +
    84 +# extract the archive
    85 +gunzip -c "$1" > "$tempcpio"/initramfs.cpio || exit 1
    86 +
    87 +# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
    88 +cp -f "$2" "$tempcpio"/DSDT.aml
    89 +
    90 +# add the file
    91 +cd "$tempcpio"
    92 +(echo DSDT.aml | cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) || exit 1
    93 +cd "$OLDPWD"
    94 +
    95 +# re-compress the archive
    96 +gzip -c "$tempcpio"/initramfs.cpio > "$1"
    97 +
    98 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
    99 index 343e0f0..76707c4 100644
    100 --- a/Documentation/kernel-parameters.txt
    101 +++ b/Documentation/kernel-parameters.txt
    102 @@ -180,6 +180,9 @@ and is between 256 and 4096 characters. It is defined in the file
    103
    104 acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
    105
    106 + acpi_no_initrd_override [KNL,ACPI]
    107 + Disable loading custom ACPI tables from the initramfs
    108 +
    109 acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
    110 Format: To spoof as Windows 98: ="Microsoft Windows"
    111
    112 diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
    113 index f4f6329..f070331 100644
    114 --- a/drivers/acpi/Kconfig
    115 +++ b/drivers/acpi/Kconfig
    116 @@ -297,6 +297,17 @@ config ACPI_CUSTOM_DSDT
    117 bool
    118 default ACPI_CUSTOM_DSDT_FILE != ""
    119
    120 +config ACPI_CUSTOM_DSDT_INITRD
    121 + bool "Read Custom DSDT from initramfs"
    122 + depends on BLK_DEV_INITRD
    123 + default n
    124 + help
    125 + This option supports a custom DSDT by optionally loading it from initrd.
    126 + See Documentation/acpi/dsdt-override.txt
    127 +
    128 + If you are not using this feature now, but may use it later,
    129 + it is safe to say Y here.
    130 +
    131 config ACPI_BLACKLIST_YEAR
    132 int "Disable ACPI for systems before Jan 1st this year" if X86_32
    133 default 0
    134 diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
    135 index 4be2521..2e0df9f 100644
    136 --- a/drivers/acpi/osl.c
    137 +++ b/drivers/acpi/osl.c
    138 @@ -96,6 +96,11 @@ static DEFINE_SPINLOCK(acpi_res_lock);
    139 #define OSI_STRING_LENGTH_MAX 64 /* arbitrary */
    140 static char osi_additional_string[OSI_STRING_LENGTH_MAX];
    141
    142 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
    143 +static __initdata int acpi_no_initrd_override;
    144 +extern struct acpi_table_header *acpi_find_dsdt_initrd(void);
    145 +#endif
    146 +
    147 /*
    148 * "Ode to _OSI(Linux)"
    149 *
    150 @@ -338,6 +343,16 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
    151 if (strncmp(existing_table->signature, "DSDT", 4) == 0)
    152 *new_table = (struct acpi_table_header *)AmlCode;
    153 #endif
    154 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
    155 + if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
    156 + !acpi_no_initrd_override) {
    157 + struct acpi_table_header *initrd_table;
    158 +
    159 + initrd_table = acpi_find_dsdt_initrd();
    160 + if (initrd_table)
    161 + *new_table = initrd_table;
    162 + }
    163 +#endif
    164 if (*new_table != NULL) {
    165 printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
    166 "this is unsafe: tainting kernel\n",
    167 @@ -348,6 +363,15 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
    168 return AE_OK;
    169 }
    170
    171 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
    172 +static int __init acpi_no_initrd_override_setup(char *s)
    173 +{
    174 + acpi_no_initrd_override = 1;
    175 + return 1;
    176 +}
    177 +__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
    178 +#endif
    179 +
    180 static irqreturn_t acpi_irq(int irq, void *dev_id)
    181 {
    182 u32 handled;
    183 diff --git a/init/initramfs.c b/init/initramfs.c
    184 index 4f5ba75..d2aaa87 100644
    185 --- a/init/initramfs.c
    186 +++ b/init/initramfs.c
    187 @@ -7,6 +7,9 @@
    188 #include <linux/string.h>
    189 #include <linux/syscalls.h>
    190 #include <linux/utime.h>
    191 +#ifdef ACPI_CONFIG
    192 +#include <acpi/acpi.h>
    193 +#endif
    194
    195 static __initdata char *message;
    196 static void __init error(char *x)
    197 @@ -124,6 +127,12 @@ static __initdata unsigned long body_len, name_len;
    198 static __initdata uid_t uid;
    199 static __initdata gid_t gid;
    200 static __initdata unsigned rdev;
    201 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
    202 +static __initdata char *file_looked_for;
    203 +static __initdata struct acpi_table_header *file_mem;
    204 +#else
    205 +const char *file_looked_for = NULL;
    206 +#endif
    207
    208 static void __init parse_header(char *s)
    209 {
    210 @@ -158,6 +167,7 @@ static __initdata enum state {
    211 SkipIt,
    212 GotName,
    213 CopyFile,
    214 + CopyFileMem,
    215 GotSymlink,
    216 Reset
    217 } state, next_state;
    218 @@ -295,6 +305,54 @@ static void __init clean_path(char *path, mode_t mode)
    219
    220 static __initdata int wfd;
    221
    222 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
    223 +static __init int is_file_looked_for(char *filename)
    224 +{
    225 + char *tmp_collected = collected;
    226 + if (file_looked_for == NULL)
    227 + return 0;
    228 + if (!S_ISREG(mode))
    229 + return 0;
    230 + /* remove the leading / */
    231 + while (*tmp_collected == '/')
    232 + tmp_collected++;
    233 + return (strcmp(tmp_collected, file_looked_for) == 0);
    234 +}
    235 +
    236 +static int __init do_copy_mem(void)
    237 +{
    238 + static void *file_current; /* current position in the memory */
    239 + if (file_mem == NULL) {
    240 + if (body_len < 4) { /* check especially against empty files */
    241 + error("file is less than 4 bytes");
    242 + return 1;
    243 + }
    244 + file_mem = kmalloc(body_len, GFP_ATOMIC);
    245 + if (!file_mem) {
    246 + error("failed to allocate enough memory");
    247 + return 1;
    248 + }
    249 + file_current = file_mem;
    250 + }
    251 + if (count >= body_len) {
    252 + memcpy(file_current, victim, body_len);
    253 + eat(body_len);
    254 + file_looked_for = NULL; /* don't find files with same name */
    255 + state = SkipIt;
    256 + return 0;
    257 + } else {
    258 + memcpy(file_current, victim, count);
    259 + file_current += count;
    260 + body_len -= count;
    261 + eat(count);
    262 + return 1;
    263 + }
    264 +}
    265 +#else
    266 +static inline int is_file_looked_for(char *filename) {return 0;}
    267 +#define do_copy_mem NULL /* because it is used as a pointer */
    268 +#endif
    269 +
    270 static int __init do_name(void)
    271 {
    272 state = SkipIt;
    273 @@ -303,6 +361,8 @@ static int __init do_name(void)
    274 free_hash();
    275 return 0;
    276 }
    277 + if (is_file_looked_for(file_looked_for))
    278 + state = CopyFileMem;
    279 if (dry_run)
    280 return 0;
    281 clean_path(collected, mode);
    282 @@ -375,6 +435,7 @@ static __initdata int (*actions[])(void) = {
    283 [SkipIt] = do_skip,
    284 [GotName] = do_name,
    285 [CopyFile] = do_copy,
    286 + [CopyFileMem] = do_copy_mem,
    287 [GotSymlink] = do_symlink,
    288 [Reset] = do_reset,
    289 };
    290 @@ -613,3 +674,31 @@ static int __init populate_rootfs(void)
    291 return 0;
    292 }
    293 rootfs_initcall(populate_rootfs);
    294 +
    295 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
    296 +struct __init acpi_table_header *acpi_find_dsdt_initrd(void)
    297 +{
    298 + char *err, *ramfs_dsdt_name = "DSDT.aml";
    299 +
    300 + printk(KERN_INFO "ACPI: Checking initramfs for custom DSDT\n");
    301 + file_mem = NULL;
    302 + file_looked_for = ramfs_dsdt_name;
    303 + err = unpack_to_rootfs((char *)initrd_start,
    304 + initrd_end - initrd_start, 1);
    305 + file_looked_for = NULL;
    306 +
    307 + if (err) {
    308 + /*
    309 + * Even if reading the DSDT file was successful,
    310 + * we give up if the initramfs cannot be entirely read.
    311 + */
    312 + kfree(file_mem);
    313 + printk(KERN_ERR "ACPI: Aborded because %s.\n", err);
    314 + return NULL;
    315 + }
    316 + if (file_mem)
    317 + printk(KERN_INFO "ACPI: Found DSDT in %s.\n", ramfs_dsdt_name);
    318 +
    319 + return file_mem;
    320 +}
    321 +#endif