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linux
1What: /sys/firmware/acpi/fpdt/
2Date: Jan 2021
3Contact: Zhang Rui <rui.zhang@intel.com>
4Description:
5 ACPI Firmware Performance Data Table (FPDT) provides
6 information for firmware performance data for system boot,
7 S3 suspend and S3 resume. This sysfs entry contains the
8 performance data retrieved from the FPDT.
9
10 boot:
11 firmware_start_ns: Timer value logged at the beginning
12 of firmware image execution. In nanoseconds.
13 bootloader_load_ns: Timer value logged just prior to
14 loading the OS boot loader into memory.
15 In nanoseconds.
16 bootloader_launch_ns: Timer value logged just prior to
17 launching the currently loaded OS boot loader
18 image. In nanoseconds.
19 exitbootservice_start_ns: Timer value logged at the
20 point when the OS loader calls the
21 ExitBootServices function for UEFI compatible
22 firmware. In nanoseconds.
23 exitbootservice_end_ns: Timer value logged at the point
24 just prior to the OS loader gaining control
25 back from the ExitBootServices function for
26 UEFI compatible firmware. In nanoseconds.
27 suspend:
28 suspend_start_ns: Timer value recorded at the previous
29 OS write to SLP_TYP upon entry to S3. In
30 nanoseconds.
31 suspend_end_ns: Timer value recorded at the previous
32 firmware write to SLP_TYP used to trigger
33 hardware entry to S3. In nanoseconds.
34 resume:
35 resume_count: A count of the number of S3 resume cycles
36 since the last full boot sequence.
37 resume_avg_ns: Average timer value of all resume cycles
38 logged since the last full boot sequence,
39 including the most recent resume. In nanoseconds.
40 resume_prev_ns: Timer recorded at the end of the previous
41 platform runtime firmware S3 resume, just prior to
42 handoff to the OS waking vector. In nanoseconds.
43
44 FBPT: The raw binary contents of the Firmware Basic Boot
45 Performance Table (FBPT) subtable.
46
47 S3PT: The raw binary contents of the S3 Performance Table
48 (S3PT) subtable.
49
50What: /sys/firmware/acpi/bgrt/
51Date: January 2012
52Contact: Matthew Garrett <mjg@redhat.com>
53Description:
54 The BGRT is an ACPI 5.0 feature that allows the OS
55 to obtain a copy of the firmware boot splash and
56 some associated metadata. This is intended to be used
57 by boot splash applications in order to interact with
58 the firmware boot splash in order to avoid jarring
59 transitions.
60
61 image: The image bitmap. Currently a 32-bit BMP.
62 status: 1 if the image is valid, 0 if firmware invalidated it.
63 type: 0 indicates image is in BMP format.
64
65 ======== ===================================================
66 version: The version of the BGRT. Currently 1.
67 xoffset: The number of pixels between the left of the screen
68 and the left edge of the image.
69 yoffset: The number of pixels between the top of the screen
70 and the top edge of the image.
71 ======== ===================================================
72
73What: /sys/firmware/acpi/hotplug/
74Date: February 2013
75Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
76Description:
77 There are separate hotplug profiles for different classes of
78 devices supported by ACPI, such as containers, memory modules,
79 processors, PCI root bridges etc. A hotplug profile for a given
80 class of devices is a collection of settings defining the way
81 that class of devices will be handled by the ACPI core hotplug
82 code. Those profiles are represented in sysfs as subdirectories
83 of /sys/firmware/acpi/hotplug/.
84
85 The following setting is available to user space for each
86 hotplug profile:
87
88 ======== =======================================================
89 enabled: If set, the ACPI core will handle notifications of
90 hotplug events associated with the given class of
91 devices and will allow those devices to be ejected with
92 the help of the _EJ0 control method. Unsetting it
93 effectively disables hotplug for the corresponding
94 class of devices.
95 ======== =======================================================
96
97 The value of the above attribute is an integer number: 1 (set)
98 or 0 (unset). Attempts to write any other values to it will
99 cause -EINVAL to be returned.
100
101What: /sys/firmware/acpi/interrupts/
102Date: February 2008
103Contact: Len Brown <lenb@kernel.org>
104Description:
105 All ACPI interrupts are handled via a single IRQ,
106 the System Control Interrupt (SCI), which appears
107 as "acpi" in /proc/interrupts.
108
109 However, one of the main functions of ACPI is to make
110 the platform understand random hardware without
111 special driver support. So while the SCI handles a few
112 well known (fixed feature) interrupts sources, such
113 as the power button, it can also handle a variable
114 number of a "General Purpose Events" (GPE).
115
116 A GPE vectors to a specified handler in AML, which
117 can do anything the BIOS writer wants from
118 OS context. GPE 0x12, for example, would vector
119 to a level or edge handler called _L12 or _E12.
120 The handler may do its business and return.
121 Or the handler may send a Notify event
122 to a Linux device driver registered on an ACPI device,
123 such as a battery, or a processor.
124
125 To figure out where all the SCIs are coming from,
126 /sys/firmware/acpi/interrupts contains a file listing
127 every possible source, and the count of how many
128 times it has triggered::
129
130 $ cd /sys/firmware/acpi/interrupts
131 $ grep . *
132 error: 0
133 ff_gbl_lock: 0 enable
134 ff_pmtimer: 0 invalid
135 ff_pwr_btn: 0 enable
136 ff_rt_clk: 2 disable
137 ff_slp_btn: 0 invalid
138 gpe00: 0 invalid
139 gpe01: 0 enable
140 gpe02: 108 enable
141 gpe03: 0 invalid
142 gpe04: 0 invalid
143 gpe05: 0 invalid
144 gpe06: 0 enable
145 gpe07: 0 enable
146 gpe08: 0 invalid
147 gpe09: 0 invalid
148 gpe0A: 0 invalid
149 gpe0B: 0 invalid
150 gpe0C: 0 invalid
151 gpe0D: 0 invalid
152 gpe0E: 0 invalid
153 gpe0F: 0 invalid
154 gpe10: 0 invalid
155 gpe11: 0 invalid
156 gpe12: 0 invalid
157 gpe13: 0 invalid
158 gpe14: 0 invalid
159 gpe15: 0 invalid
160 gpe16: 0 invalid
161 gpe17: 1084 enable
162 gpe18: 0 enable
163 gpe19: 0 invalid
164 gpe1A: 0 invalid
165 gpe1B: 0 invalid
166 gpe1C: 0 invalid
167 gpe1D: 0 invalid
168 gpe1E: 0 invalid
169 gpe1F: 0 invalid
170 gpe_all: 1192
171 sci: 1194
172 sci_not: 0
173
174 =========== ==================================================
175 sci The number of times the ACPI SCI
176 has been called and claimed an interrupt.
177
178 sci_not The number of times the ACPI SCI
179 has been called and NOT claimed an interrupt.
180
181 gpe_all count of SCI caused by GPEs.
182
183 gpeXX count for individual GPE source
184
185 ff_gbl_lock Global Lock
186
187 ff_pmtimer PM Timer
188
189 ff_pwr_btn Power Button
190
191 ff_rt_clk Real Time Clock
192
193 ff_slp_btn Sleep Button
194
195 error an interrupt that can't be accounted for above.
196
197 invalid it's either a GPE or a Fixed Event that
198 doesn't have an event handler.
199
200 disable the GPE/Fixed Event is valid but disabled.
201
202 enable the GPE/Fixed Event is valid and enabled.
203 =========== ==================================================
204
205 Root has permission to clear any of these counters. Eg.::
206
207 # echo 0 > gpe11
208
209 All counters can be cleared by clearing the total "sci"::
210
211 # echo 0 > sci
212
213 None of these counters has an effect on the function
214 of the system, they are simply statistics.
215
216 Besides this, user can also write specific strings to these files
217 to enable/disable/clear ACPI interrupts in user space, which can be
218 used to debug some ACPI interrupt storm issues.
219
220 Note that only writing to VALID GPE/Fixed Event is allowed,
221 i.e. user can only change the status of runtime GPE and
222 Fixed Event with event handler installed.
223
224 Let's take power button fixed event for example, please kill acpid
225 and other user space applications so that the machine won't shutdown
226 when pressing the power button::
227
228 # cat ff_pwr_btn
229 0 enabled
230 # press the power button for 3 times;
231 # cat ff_pwr_btn
232 3 enabled
233 # echo disable > ff_pwr_btn
234 # cat ff_pwr_btn
235 3 disabled
236 # press the power button for 3 times;
237 # cat ff_pwr_btn
238 3 disabled
239 # echo enable > ff_pwr_btn
240 # cat ff_pwr_btn
241 4 enabled
242 /*
243 * this is because the status bit is set even if the enable
244 * bit is cleared, and it triggers an ACPI fixed event when
245 * the enable bit is set again
246 */
247 # press the power button for 3 times;
248 # cat ff_pwr_btn
249 7 enabled
250 # echo disable > ff_pwr_btn
251 # press the power button for 3 times;
252 # echo clear > ff_pwr_btn /* clear the status bit */
253 # echo disable > ff_pwr_btn
254 # cat ff_pwr_btn
255 7 enabled
256
257What: /sys/firmware/acpi/memory_ranges/rangeX
258Date: February 2025
259Contact: Tony Luck <tony.luck@intel.com>
260Description:
261 On systems with the ACPI MRRM table reports the parameters for
262 each range.
263
264 base: Starting system physical address.
265
266 length: Length of this range in bytes.
267
268 node: NUMA node that this range belongs to. Negative numbers
269 indicate that the node number could not be determined (e.g
270 for an address range that is reserved for future hot add of
271 memory).
272
273 local_region_id: ID associated with access by agents
274 local to this range of addresses.
275
276 remote_region_id: ID associated with access by agents
277 non-local to this range of addresses.