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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
| commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
| tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/ABI/testing/sysfs-firmware-efi-runtime-map | |
| parent | Initial commit. (diff) | |
| download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip | |
Adding upstream version 5.10.209.upstream/5.10.209upstream
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 |