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author | Ingo Molnar <mingo@elte.hu> | 2008-07-15 23:12:58 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-15 23:12:58 +0200 |
commit | 1e09481365ce248dbb4eb06dad70129bb5807037 (patch) | |
tree | c0cff5bef95c8b5e7486f144718ade9a06c284dc /Documentation/ABI/testing/sysfs-firmware-memmap | |
parent | 3e2f69fdd1b00166e7d589bce56b2d36a9e74374 (diff) | |
parent | b9d2252c1e44fa83a4e65fdc9eb93db6297c55af (diff) |
Merge branch 'linus' into core/softlockup
Conflicts:
kernel/softlockup.c
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-firmware-memmap')
-rw-r--r-- | Documentation/ABI/testing/sysfs-firmware-memmap | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-firmware-memmap b/Documentation/ABI/testing/sysfs-firmware-memmap new file mode 100644 index 00000000000..0d99ee6ae02 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-firmware-memmap @@ -0,0 +1,71 @@ +What: /sys/firmware/memmap/ +Date: June 2008 +Contact: Bernhard Walle <bwalle@suse.de> +Description: + On all platforms, the firmware provides a memory map which the + kernel reads. The resources from that memory map are registered + in the kernel resource tree and exposed to userspace via + /proc/iomem (together with other resources). + + However, on most architectures that firmware-provided memory + map is modified afterwards by the kernel itself, either because + the kernel merges that memory map with other information or + just because the user overwrites that memory map via command + line. + + kexec needs the raw firmware-provided memory map to setup the + parameter segment of the kernel that should be booted with + kexec. Also, the raw memory map is useful for debugging. For + that reason, /sys/firmware/memmap is an interface that provides + the raw memory map to userspace. + + The structure is as follows: Under /sys/firmware/memmap there + are subdirectories with the number of the entry as their name: + + /sys/firmware/memmap/0 + /sys/firmware/memmap/1 + /sys/firmware/memmap/2 + /sys/firmware/memmap/3 + ... + + The maximum depends on the number of memory map entries provided + by the firmware. The order is just the order that the firmware + provides. + + Each directory contains three files: + + start : The start address (as hexadecimal number with the + '0x' prefix). + end : The end address, inclusive (regardless whether the + firmware provides inclusive or exclusive ranges). + type : Type of the entry as string. See below for a list of + valid types. + + So, for example: + + /sys/firmware/memmap/0/start + /sys/firmware/memmap/0/end + /sys/firmware/memmap/0/type + /sys/firmware/memmap/1/start + ... + + Currently following types exist: + + - System RAM + - ACPI Tables + - ACPI Non-volatile Storage + - reserved + + Following shell snippet can be used to display that memory + map in a human-readable format: + + -------------------- 8< ---------------------------------------- + #!/bin/bash + cd /sys/firmware/memmap + for dir in * ; do + start=$(cat $dir/start) + end=$(cat $dir/end) + type=$(cat $dir/type) + printf "%016x-%016x (%s)\n" $start $[ $end +1] "$type" + done + -------------------- >8 ---------------------------------------- |