1 What: /sys/firmware/memmap/
2 Date: June 2008
3 Contact: Bernhard Walle <bernhard.walle@
4 Description:
5 On all platforms, the firmware
6 kernel reads. The resources fr
7 in the kernel resource tree an
8 /proc/iomem (together with oth
9
10 However, on most architectures
11 map is modified afterwards by
12 the kernel merges that memory
13 just because the user overwrit
14 line.
15
16 kexec needs the raw firmware-p
17 parameter segment of the kerne
18 kexec. Also, the raw memory ma
19 that reason, /sys/firmware/mem
20 the raw memory map to userspac
21
22 The structure is as follows: U
23 are subdirectories with the nu
24
25 /sys/firmware/memmap/0
26 /sys/firmware/memmap/1
27 /sys/firmware/memmap/2
28 /sys/firmware/memmap/3
29 ...
30
31 The maximum depends on the num
32 by the firmware. The order is
33 provides.
34
35 Each directory contains three
36
37 ======== ====================
38 start The start address (a
39 '0x' prefix).
40 end The end address, inc
41 firmware provides in
42 type Type of the entry as
43 valid types.
44 ======== ====================
45
46 So, for example::
47
48 /sys/firmware/memmap/0
49 /sys/firmware/memmap/0
50 /sys/firmware/memmap/0
51 /sys/firmware/memmap/1
52 ...
53
54 Currently following types exis
55
56 - System RAM
57 - ACPI Tables
58 - ACPI Non-volatile Storage
59 - Unusable memory
60 - Persistent Memory (legacy)
61 - Persistent Memory
62 - Soft Reserved
63 - reserved
64
65 Following shell snippet can be
66 map in a human-readable format
67
68 #!/bin/bash
69 cd /sys/firmware/memmap
70 for dir in * ; do
71 start=$(cat $dir/start)
72 end=$(cat $dir/end)
73 type=$(cat $dir/type)
74 printf "%016x-%016x (%s)
75 done
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.