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Zhang Ruid1eb86e2021-01-29 14:15:48 +08001What: /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
Matthew Garrettd1ff4b12012-01-31 13:19:20 -050044What: /sys/firmware/acpi/bgrt/
45Date: January 2012
46Contact: Matthew Garrett <mjg@redhat.com>
47Description:
48 The BGRT is an ACPI 5.0 feature that allows the OS
49 to obtain a copy of the firmware boot splash and
50 some associated metadata. This is intended to be used
51 by boot splash applications in order to interact with
52 the firmware boot splash in order to avoid jarring
53 transitions.
54
55 image: The image bitmap. Currently a 32-bit BMP.
56 status: 1 if the image is valid, 0 if firmware invalidated it.
57 type: 0 indicates image is in BMP format.
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +010058
59 ======== ===================================================
Matthew Garrettd1ff4b12012-01-31 13:19:20 -050060 version: The version of the BGRT. Currently 1.
61 xoffset: The number of pixels between the left of the screen
62 and the left edge of the image.
63 yoffset: The number of pixels between the top of the screen
64 and the top edge of the image.
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +010065 ======== ===================================================
Matthew Garrettd1ff4b12012-01-31 13:19:20 -050066
Rafael J. Wysocki3f8055c2013-03-03 23:08:16 +010067What: /sys/firmware/acpi/hotplug/
68Date: February 2013
69Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
70Description:
71 There are separate hotplug profiles for different classes of
72 devices supported by ACPI, such as containers, memory modules,
73 processors, PCI root bridges etc. A hotplug profile for a given
74 class of devices is a collection of settings defining the way
75 that class of devices will be handled by the ACPI core hotplug
76 code. Those profiles are represented in sysfs as subdirectories
77 of /sys/firmware/acpi/hotplug/.
78
79 The following setting is available to user space for each
80 hotplug profile:
81
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +010082 ======== =======================================================
Rafael J. Wysocki3f8055c2013-03-03 23:08:16 +010083 enabled: If set, the ACPI core will handle notifications of
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +010084 hotplug events associated with the given class of
85 devices and will allow those devices to be ejected with
86 the help of the _EJ0 control method. Unsetting it
87 effectively disables hotplug for the correspoinding
88 class of devices.
89 ======== =======================================================
Rafael J. Wysocki3f8055c2013-03-03 23:08:16 +010090
91 The value of the above attribute is an integer number: 1 (set)
92 or 0 (unset). Attempts to write any other values to it will
93 cause -EINVAL to be returned.
94
Len Brown5229e872008-02-06 01:26:55 -050095What: /sys/firmware/acpi/interrupts/
96Date: February 2008
97Contact: Len Brown <lenb@kernel.org>
98Description:
99 All ACPI interrupts are handled via a single IRQ,
100 the System Control Interrupt (SCI), which appears
101 as "acpi" in /proc/interrupts.
102
103 However, one of the main functions of ACPI is to make
104 the platform understand random hardware without
105 special driver support. So while the SCI handles a few
106 well known (fixed feature) interrupts sources, such
107 as the power button, it can also handle a variable
108 number of a "General Purpose Events" (GPE).
109
110 A GPE vectors to a specified handler in AML, which
111 can do a anything the BIOS writer wants from
112 OS context. GPE 0x12, for example, would vector
113 to a level or edge handler called _L12 or _E12.
114 The handler may do its business and return.
115 Or the handler may send send a Notify event
116 to a Linux device driver registered on an ACPI device,
117 such as a battery, or a processor.
118
119 To figure out where all the SCI's are coming from,
120 /sys/firmware/acpi/interrupts contains a file listing
121 every possible source, and the count of how many
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100122 times it has triggered::
Len Brown5229e872008-02-06 01:26:55 -0500123
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100124 $ cd /sys/firmware/acpi/interrupts
125 $ grep . *
126 error: 0
Mauro Carvalho Chehab54a19b42020-10-30 08:40:50 +0100127 ff_gbl_lock: 0 enable
128 ff_pmtimer: 0 invalid
129 ff_pwr_btn: 0 enable
130 ff_rt_clk: 2 disable
131 ff_slp_btn: 0 invalid
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100132 gpe00: 0 invalid
133 gpe01: 0 enable
134 gpe02: 108 enable
135 gpe03: 0 invalid
136 gpe04: 0 invalid
137 gpe05: 0 invalid
138 gpe06: 0 enable
139 gpe07: 0 enable
140 gpe08: 0 invalid
141 gpe09: 0 invalid
142 gpe0A: 0 invalid
143 gpe0B: 0 invalid
144 gpe0C: 0 invalid
145 gpe0D: 0 invalid
146 gpe0E: 0 invalid
147 gpe0F: 0 invalid
148 gpe10: 0 invalid
149 gpe11: 0 invalid
150 gpe12: 0 invalid
151 gpe13: 0 invalid
152 gpe14: 0 invalid
153 gpe15: 0 invalid
154 gpe16: 0 invalid
155 gpe17: 1084 enable
156 gpe18: 0 enable
157 gpe19: 0 invalid
158 gpe1A: 0 invalid
159 gpe1B: 0 invalid
160 gpe1C: 0 invalid
161 gpe1D: 0 invalid
162 gpe1E: 0 invalid
163 gpe1F: 0 invalid
Mauro Carvalho Chehab54a19b42020-10-30 08:40:50 +0100164 gpe_all: 1192
165 sci: 1194
166 sci_not: 0
Len Brown5229e872008-02-06 01:26:55 -0500167
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100168 =========== ==================================================
169 sci The number of times the ACPI SCI
170 has been called and claimed an interrupt.
Len Brown88bea182009-04-21 00:35:47 -0400171
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100172 sci_not The number of times the ACPI SCI
173 has been called and NOT claimed an interrupt.
Len Brown5229e872008-02-06 01:26:55 -0500174
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100175 gpe_all count of SCI caused by GPEs.
Len Brown5229e872008-02-06 01:26:55 -0500176
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100177 gpeXX count for individual GPE source
Len Brown5229e872008-02-06 01:26:55 -0500178
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100179 ff_gbl_lock Global Lock
Len Brown5229e872008-02-06 01:26:55 -0500180
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100181 ff_pmtimer PM Timer
Len Brown5229e872008-02-06 01:26:55 -0500182
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100183 ff_pwr_btn Power Button
Len Brown5229e872008-02-06 01:26:55 -0500184
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100185 ff_rt_clk Real Time Clock
Len Brown5229e872008-02-06 01:26:55 -0500186
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100187 ff_slp_btn Sleep Button
Len Brown5229e872008-02-06 01:26:55 -0500188
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100189 error an interrupt that can't be accounted for above.
Len Brown5229e872008-02-06 01:26:55 -0500190
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100191 invalid it's either a GPE or a Fixed Event that
192 doesn't have an event handler.
Zhang Rui71b58cb2008-06-20 09:42:47 +0800193
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100194 disable the GPE/Fixed Event is valid but disabled.
Zhang Rui71b58cb2008-06-20 09:42:47 +0800195
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100196 enable the GPE/Fixed Event is valid and enabled.
197 =========== ==================================================
Zhang Rui71b58cb2008-06-20 09:42:47 +0800198
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100199 Root has permission to clear any of these counters. Eg.::
Len Brown5229e872008-02-06 01:26:55 -0500200
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100201 # echo 0 > gpe11
202
203 All counters can be cleared by clearing the total "sci"::
204
205 # echo 0 > sci
Len Brown5229e872008-02-06 01:26:55 -0500206
207 None of these counters has an effect on the function
208 of the system, they are simply statistics.
Zhang Rui71b58cb2008-06-20 09:42:47 +0800209
210 Besides this, user can also write specific strings to these files
211 to enable/disable/clear ACPI interrupts in user space, which can be
212 used to debug some ACPI interrupt storm issues.
213
Kees Cook08559652016-04-26 16:41:21 -0700214 Note that only writing to VALID GPE/Fixed Event is allowed,
Zhang Rui71b58cb2008-06-20 09:42:47 +0800215 i.e. user can only change the status of runtime GPE and
216 Fixed Event with event handler installed.
217
218 Let's take power button fixed event for example, please kill acpid
219 and other user space applications so that the machine won't shutdown
Mauro Carvalho Chehab34433332020-10-30 08:40:39 +0100220 when pressing the power button::
221
222 # cat ff_pwr_btn
223 0 enabled
224 # press the power button for 3 times;
225 # cat ff_pwr_btn
226 3 enabled
227 # echo disable > ff_pwr_btn
228 # cat ff_pwr_btn
229 3 disabled
230 # press the power button for 3 times;
231 # cat ff_pwr_btn
232 3 disabled
233 # echo enable > ff_pwr_btn
234 # cat ff_pwr_btn
235 4 enabled
236 /*
237 * this is because the status bit is set even if the enable
238 * bit is cleared, and it triggers an ACPI fixed event when
239 * the enable bit is set again
240 */
241 # press the power button for 3 times;
242 # cat ff_pwr_btn
243 7 enabled
244 # echo disable > ff_pwr_btn
245 # press the power button for 3 times;
246 # echo clear > ff_pwr_btn /* clear the status bit */
247 # echo disable > ff_pwr_btn
248 # cat ff_pwr_btn
249 7 enabled
Zhang Rui71b58cb2008-06-20 09:42:47 +0800250