diff options
| author | Len Brown <len.brown@intel.com> | 2007-11-23 20:08:02 -0500 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2007-12-14 02:36:24 -0500 |
| commit | 239665a3bb0a2234980f918913add31bc536cfd1 (patch) | |
| tree | 260262706ce5223bf3d1cec0e8083ea42260f2fb /arch/x86/kernel/acpi/boot.c | |
| parent | 2ffbb8377c7a0713baf6644e285adc27a5654582 (diff) | |
ACPI: tables: complete searching upon RSDP w/ bad checksum.
ACPI tables follow a tree structure in memory.
The root of the tree is the RSDP (Root System Description Pointer).
To find the RSDP, the OS searches for the signature "RSD PTR "
in well known physical memory locations. Then the OS computes
a table checksum to verify that the signature is really part
of a valid table header.
Some systems have a proper signature but an invalid checksum;
followed elsewhere by a proper signature with valid checksum.
http://bugzilla.kernel.org/show_bug.cgi?id=9444
The Linux RSDP scanning code bailed out on those systems
and as a result they booted with ACPI disabled.
Fix this by deleting the Linux RSDP scanning code and
plugging in the ACPICA RSDP scanning code.
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
| -rw-r--r-- | arch/x86/kernel/acpi/boot.c | 40 |
1 files changed, 0 insertions, 40 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 0ca27c7b0e8..719c74b0141 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -581,25 +581,6 @@ int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base) EXPORT_SYMBOL(acpi_unregister_ioapic); -static unsigned long __init -acpi_scan_rsdp(unsigned long start, unsigned long length) -{ - unsigned long offset = 0; - unsigned long sig_len = sizeof("RSD PTR ") - 1; - - /* - * Scan all 16-byte boundaries of the physical memory region for the - * RSDP signature. - */ - for (offset = 0; offset < length; offset += 16) { - if (strncmp((char *)(phys_to_virt(start) + offset), "RSD PTR ", sig_len)) - continue; - return (start + offset); - } - - return 0; -} - static int __init acpi_parse_sbf(struct acpi_table_header *table) { struct acpi_table_boot *sb; @@ -742,27 +723,6 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table) return 0; } -unsigned long __init acpi_find_rsdp(void) -{ - unsigned long rsdp_phys = 0; - - if (efi_enabled) { - if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) - return efi.acpi20; - else if (efi.acpi != EFI_INVALID_TABLE_ADDR) - return efi.acpi; - } - /* - * Scan memory looking for the RSDP signature. First search EBDA (low - * memory) paragraphs and then search upper memory (E0000-FFFFF). - */ - rsdp_phys = acpi_scan_rsdp(0, 0x400); - if (!rsdp_phys) - rsdp_phys = acpi_scan_rsdp(0xE0000, 0x20000); - - return rsdp_phys; -} - #ifdef CONFIG_X86_LOCAL_APIC /* * Parse LAPIC entries in MADT |