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| author | Steve McIntyre <steve@einval.com> | 2015-01-09 15:29:53 +0000 |
|---|---|---|
| committer | Matt Fleming <matt.fleming@intel.com> | 2015-01-12 11:51:32 +0000 |
| commit | 2859dff97e54db4795b8b7d9606cb8efcec722ff (patch) | |
| tree | 91836ca6535a94c9fe92972d9c01911f5e0d79ba | |
| parent | 17473c32ce23568d39b076bf56159894bea1c61f (diff) | |
| download | linux-stable-2859dff97e54db4795b8b7d9606cb8efcec722ff.tar.gz linux-stable-2859dff97e54db4795b8b7d9606cb8efcec722ff.tar.bz2 linux-stable-2859dff97e54db4795b8b7d9606cb8efcec722ff.zip | |
efi: Expose underlying UEFI firmware platform size to userland
In some cases (e.g. Intel Bay Trail machines), the kernel will happily
run in 64-bit even if the underlying UEFI firmware platform is
32-bit. That's great, but it's difficult for userland utilities like
grub-install to do the right thing in such a situation.
The kernel already knows about the size of the firmware via
efi_enabled(EFI_64BIT). Add an extra sysfs interface
/sys/firmware/efi/fw_platform_size to expose that information to
userland for low-level utilities to use.
Signed-off-by: Steve McIntyre <steve@einval.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
| -rw-r--r-- | drivers/firmware/efi/efi.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index ff0bbe383b31..9bdbc0533627 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -112,15 +112,24 @@ EFI_ATTR_SHOW(fw_vendor); EFI_ATTR_SHOW(runtime); EFI_ATTR_SHOW(config_table); +static ssize_t fw_platform_size_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32); +} + static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); +static struct kobj_attribute efi_attr_fw_platform_size = + __ATTR_RO(fw_platform_size); static struct attribute *efi_subsys_attrs[] = { &efi_attr_systab.attr, &efi_attr_fw_vendor.attr, &efi_attr_runtime.attr, &efi_attr_config_table.attr, + &efi_attr_fw_platform_size.attr, NULL, }; |