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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
| commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
| tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/ABI/testing/sysfs-firmware-efi-runtime-map | |
| parent | Initial commit. (diff) | |
| download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip | |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-firmware-efi-runtime-map')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-firmware-efi-runtime-map | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map new file mode 100644 index 000000000..9c4d581be --- /dev/null +++ b/Documentation/ABI/testing/sysfs-firmware-efi-runtime-map @@ -0,0 +1,36 @@ +What: /sys/firmware/efi/runtime-map/ +Date: December 2013 +Contact: Dave Young <dyoung@redhat.com> +Description: Switching efi runtime services to virtual mode requires + that all efi memory ranges which have the runtime attribute + bit set to be mapped to virtual addresses. + + The efi runtime services can only be switched to virtual + mode once without rebooting. The kexec kernel must maintain + the same physical to virtual address mappings as the first + kernel. The mappings are exported to sysfs so userspace tools + can reassemble them and pass them into the kexec kernel. + + /sys/firmware/efi/runtime-map/ is the directory the kernel + exports that information in. + + subdirectories are named with the number of the memory range:: + + /sys/firmware/efi/runtime-map/0 + /sys/firmware/efi/runtime-map/1 + /sys/firmware/efi/runtime-map/2 + /sys/firmware/efi/runtime-map/3 + ... + + Each subdirectory contains five files: + + ========= ========================================= + attribute The attributes of the memory range. + num_pages The size of the memory range in pages. + phys_addr The physical address of the memory range. + type The type of the memory range. + virt_addr The virtual address of the memory range. + ========= ========================================= + + Above values are all hexadecimal numbers with the '0x' prefix. +Users: Kexec |