diff -urN linux-2.6.17-rc1-mm3-orig/Documentation/dsdt-initrd.txt linux-2.6.17-rc1-mm3-new/Documentation/dsdt-initrd.txt --- linux-2.6.17-rc1-mm3-orig/Documentation/dsdt-initrd.txt 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.17-rc1-mm3-new/Documentation/dsdt-initrd.txt 2006-04-22 12:33:18.329405261 +0000 @@ -0,0 +1,83 @@ +ACPI Custom DSDT read from initramfs + +2003 by Markuss Gaugusch < dsdt at gaugusch dot org > +Special thanks go to Thomas Renninger from SuSE, who updated the patch for +2.6.0 and later modified it to read inside initramfs +2004, 2005 maintained by Eric Piel < eric dot piel at tremplin-utc dot net > + +This option is intended for people who would like to hack their DSDT and don't want +to recompile their kernel after every change. It can also be useful to distros +which offers pre-compiled kernels and want to allow their users to use a +modified DSDT. In the Kernel config, enable the ramdisk (not as module!) and initrd +(in Block Devices) and enable ACPI_CUSTOM_DSDT_INITRD at the ACPI +options (General Setup|ACPI Support|Read custom DSDT from initrd). + +A custom DSDT (Differentiated System Description Table) is useful when your +computer uses ACPI but problems occur due to broken implementation. Typically, +your computer works but there are some troubles with the hardware detection or +the power management. You can check that troubles come from errors in the DSDT by +activating the ACPI debug option and reading the logs. This table is provided +by the BIOS, therefore it might be a good idea to check for BIOS update on your +vendor website before going any further. Errors are often caused by vendors +testing their hardware only with Windows or because there is code which is +executed only on a specific OS with a specific version and Linux hasn't been +considered during the development. + +Before you run away from customising your DSDT, you should note that already +corrected tables are available for a fair amount of computers on this web-page: +http://acpi.sf.net/dsdt . If you are part of the unluckies who cannot find +their hardware in this database, you can modify your DSDT by yourself. This +process is less painful than it sounds. Download the Intel ASL +compiler/decompiler at http://www.intel.com/technology/IAPC/acpi/downloads.htm . +As root, you then have to dump your DSDT and decompile it. By using the +compiler messages as well as the kernel ACPI debug messages and the reference book +(available at the Intel website and also at http://www.acpi.info), it is quite +easy to obtain a fully working table. + +Once your new DSDT is ready you'll have to add it to an initrd so that the +kernel can read the table at the very beginning of the boot. As the file has +to be accessed very early during the boot process the initrd has to be an +initramfs. The file is contained into the initramfs under the name /DSDT.aml . +To obtain such an initrd, you might have to modify your mkinitrd script or you +can add it later to the initrd with the script appended to this document. The +command will look like: +initrd-add initrd.img DSDT.aml + +The message "Looking for DSDT in initrd..." will tell you if the DSDT was +found or not. If you need to update your DSDT, generate a new initrd and +perform the steps above. Don't forget that with Lilo, you'll have to re-run it. + + +======================== Here starts initrd-add ================================ +#!/bin/bash +# Adds a file to the initrd (if it's an initramfs) +# first argument is the name of archive +# second argurment is the name of the file to add + +# check the arguments +if [ $# -ne 2 ]; then + program_name=$(basename $0) + echo "\ +$program_name: too few arguments +Usage: $program_name initrd-name.img file-to-add +Adds a file to an initrd (in initramfs format) + + initrd-name.img: filename of the initrd in initramfs format + file-to-add: filename of the file to add + " 1>&2 + exit 1 +fi + +tempcpio=$(mktemp) +# cleanup on exit, hangup, interrupt, quit, termination +trap 'rm -f $tempcpio' 0 1 2 3 15 + +# extract the archive +gunzip -c "$1" > $tempcpio || exit 1 + +# add the file +(echo "$2" | cpio --quiet -c -o -A -O $tempcpio) || exit 1 + +# re-compress the archive +gzip -c $tempcpio > "$1" + diff -urN linux-2.6.17-rc1-mm3-orig/drivers/acpi/Kconfig linux-2.6.17-rc1-mm3-new/drivers/acpi/Kconfig --- linux-2.6.17-rc1-mm3-orig/drivers/acpi/Kconfig 2006-04-21 22:15:20.366777750 +0000 +++ linux-2.6.17-rc1-mm3-new/drivers/acpi/Kconfig 2006-04-22 12:33:18.353401613 +0000 @@ -278,6 +278,23 @@ Enter the full path name to the file which includes the AmlCode declaration. +config ACPI_CUSTOM_DSDT_INITRD + bool "Read Custom DSDT from initramfs" + depends on X86 + depends on BLK_DEV_INITRD + default y + help + The DSDT (Differentiated System Description Table) often needs to be + overridden because of broken BIOS implementations. If this feature is + activated you will be able to provide a customized DSDT by adding it to your + initrd (initramfs only). For now you need to use a special mkinitrd tool. + For more details see file: Documentation/dsdt-initrd.txt . If there is no + table found, it will fallback to the custom DSDT in-kernel (if activated) or + to the DSDT from the BIOS. + + Even if you do not need a new one at the moment, you may want to use a + better implemented DSDT 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 -urN linux-2.6.17-rc1-mm3-orig/drivers/acpi/osl.c linux-2.6.17-rc1-mm3-new/drivers/acpi/osl.c --- linux-2.6.17-rc1-mm3-orig/drivers/acpi/osl.c 2006-04-21 22:15:20.378778500 +0000 +++ linux-2.6.17-rc1-mm3-new/drivers/acpi/osl.c 2006-04-22 12:33:18.381397357 +0000 @@ -70,6 +70,10 @@ int acpi_specific_hotkey_enabled = TRUE; EXPORT_SYMBOL(acpi_specific_hotkey_enabled); +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD +int acpi_must_unregister_table = FALSE; +#endif + static unsigned int acpi_irq_irq; static acpi_osd_handler acpi_irq_handler; static void *acpi_irq_context; @@ -238,6 +242,67 @@ return AE_OK; } +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD +struct acpi_table_header * acpi_find_dsdt_initrd(void) +{ + struct file *firmware_file; + mm_segment_t oldfs; + unsigned long len, len2; + struct acpi_table_header *dsdt_buffer, *ret = NULL; + struct kstat stat; + /* maybe this could be an argument on the cmd line, but let's keep it simple for now */ + char *ramfs_dsdt_name = "/DSDT.aml"; + + printk(KERN_INFO PREFIX "Looking for DSDT in initramfs... "); + + /* + * Never do this at home, only the user-space is allowed to open a file. + * The clean way would be to use the firmware loader. But this code must be run + * before there is any userspace available. So we need a static/init firmware + * infrastructure, which doesn't exist yet... + */ + if (vfs_stat(ramfs_dsdt_name, &stat) < 0) { + printk("error, file %s not found.\n", ramfs_dsdt_name); + return ret; + } + + len = stat.size; + /* check especially against empty files */ + if (len <= 4) { + printk("error file is too small, only %lu bytes.\n", len); + return ret; + } + + firmware_file = filp_open(ramfs_dsdt_name, O_RDONLY, 0); + if (IS_ERR(firmware_file)) { + printk("error, could not open file %s.\n", ramfs_dsdt_name); + return ret; + } + + dsdt_buffer = ACPI_MEM_ALLOCATE(len); + if (!dsdt_buffer) { + printk("error when allocating %lu bytes of memory.\n", len); + goto err; + } + + oldfs = get_fs(); + set_fs(KERNEL_DS); + len2 = vfs_read(firmware_file, (char __user *)dsdt_buffer, len, &firmware_file->f_pos); + set_fs(oldfs); + if (len2 < len) { + printk("error trying to read %lu bytes from %s.\n", len, ramfs_dsdt_name); + ACPI_MEM_FREE(dsdt_buffer); + goto err; + } + + printk("successfully read %lu bytes from %s.\n", len, ramfs_dsdt_name); + ret = dsdt_buffer; +err: + filp_close(firmware_file, NULL); + return ret; +} +#endif + acpi_status acpi_os_table_override(struct acpi_table_header * existing_table, struct acpi_table_header ** new_table) @@ -245,13 +310,20 @@ if (!existing_table || !new_table) return AE_BAD_PARAMETER; + *new_table = NULL; + #ifdef CONFIG_ACPI_CUSTOM_DSDT if (strncmp(existing_table->signature, "DSDT", 4) == 0) *new_table = (struct acpi_table_header *)AmlCode; - else - *new_table = NULL; -#else - *new_table = NULL; +#endif +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD + if (strncmp(existing_table->signature, "DSDT", 4) == 0) { + struct acpi_table_header* initrd_table = acpi_find_dsdt_initrd(); + if (initrd_table) { + *new_table = initrd_table; + acpi_must_unregister_table = TRUE; + } + } #endif return AE_OK; } diff -urN linux-2.6.17-rc1-mm3-orig/drivers/acpi/tables/tbget.c linux-2.6.17-rc1-mm3-new/drivers/acpi/tables/tbget.c --- linux-2.6.17-rc1-mm3-orig/drivers/acpi/tables/tbget.c 2006-04-21 22:15:20.402780000 +0000 +++ linux-2.6.17-rc1-mm3-new/drivers/acpi/tables/tbget.c 2006-04-22 12:33:18.401394317 +0000 @@ -278,6 +278,14 @@ address.pointer.logical = new_table; status = acpi_tb_get_this_table(&address, new_table, table_info); + +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD + if (acpi_must_unregister_table) { + ACPI_MEM_FREE(new_table); + acpi_must_unregister_table = FALSE; + } +#endif + if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Could not copy ACPI table")); return_ACPI_STATUS(status); diff -urN linux-2.6.17-rc1-mm3-orig/include/acpi/acpiosxf.h linux-2.6.17-rc1-mm3-new/include/acpi/acpiosxf.h --- linux-2.6.17-rc1-mm3-orig/include/acpi/acpiosxf.h 2006-04-21 22:15:21.590854250 +0000 +++ linux-2.6.17-rc1-mm3-new/include/acpi/acpiosxf.h 2006-04-22 12:33:18.411392798 +0000 @@ -91,6 +91,10 @@ acpi_os_table_override(struct acpi_table_header *existing_table, struct acpi_table_header **new_table); +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD +extern int acpi_must_unregister_table; +#endif + /* * Synchronization primitives */ diff -urN linux-2.6.17-rc1-mm3-orig/init/main.c linux-2.6.17-rc1-mm3-new/init/main.c --- linux-2.6.17-rc1-mm3-orig/init/main.c 2006-04-21 22:15:21.770865500 +0000 +++ linux-2.6.17-rc1-mm3-new/init/main.c 2006-04-22 12:33:18.450386869 +0000 @@ -567,8 +567,6 @@ check_bugs(); - acpi_early_init(); /* before LAPIC and SMP init */ - /* Do the rest non-__init'ed, we're now alive */ rest_init(); } @@ -685,6 +683,14 @@ */ child_reaper = current; + /* + * Do this before initcalls, because some drivers want to access + * firmware files. + */ + populate_rootfs(); + + acpi_early_init(); /* before LAPIC and SMP init */ + smp_prepare_cpus(max_cpus); do_pre_smp_initcalls(); @@ -694,12 +700,6 @@ cpuset_init_smp(); - /* - * Do this before initcalls, because some drivers want to access - * firmware files. - */ - populate_rootfs(); - do_basic_setup(); /*