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1What: /sys/firmware/acpi/fpdt/2Date: Jan 20213Contact: Zhang Rui <rui.zhang@intel.com>4Description:5 ACPI Firmware Performance Data Table (FPDT) provides6 information for firmware performance data for system boot,7 S3 suspend and S3 resume. This sysfs entry contains the8 performance data retrieved from the FPDT.9 10 boot:11 firmware_start_ns: Timer value logged at the beginning12 of firmware image execution. In nanoseconds.13 bootloader_load_ns: Timer value logged just prior to14 loading the OS boot loader into memory.15 In nanoseconds.16 bootloader_launch_ns: Timer value logged just prior to17 launching the currently loaded OS boot loader18 image. In nanoseconds.19 exitbootservice_start_ns: Timer value logged at the20 point when the OS loader calls the21 ExitBootServices function for UEFI compatible22 firmware. In nanoseconds.23 exitbootservice_end_ns: Timer value logged at the point24 just prior to the OS loader gaining control25 back from the ExitBootServices function for26 UEFI compatible firmware. In nanoseconds.27 suspend:28 suspend_start_ns: Timer value recorded at the previous29 OS write to SLP_TYP upon entry to S3. In30 nanoseconds.31 suspend_end_ns: Timer value recorded at the previous32 firmware write to SLP_TYP used to trigger33 hardware entry to S3. In nanoseconds.34 resume:35 resume_count: A count of the number of S3 resume cycles36 since the last full boot sequence.37 resume_avg_ns: Average timer value of all resume cycles38 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 previous41 platform runtime firmware S3 resume, just prior to42 handoff to the OS waking vector. In nanoseconds.43 44What: /sys/firmware/acpi/bgrt/45Date: January 201246Contact: Matthew Garrett <mjg@redhat.com>47Description:48 The BGRT is an ACPI 5.0 feature that allows the OS49 to obtain a copy of the firmware boot splash and50 some associated metadata. This is intended to be used51 by boot splash applications in order to interact with52 the firmware boot splash in order to avoid jarring53 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.58 59 ======== ===================================================60 version: The version of the BGRT. Currently 1.61 xoffset: The number of pixels between the left of the screen62 and the left edge of the image.63 yoffset: The number of pixels between the top of the screen64 and the top edge of the image.65 ======== ===================================================66 67What: /sys/firmware/acpi/hotplug/68Date: February 201369Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>70Description:71 There are separate hotplug profiles for different classes of72 devices supported by ACPI, such as containers, memory modules,73 processors, PCI root bridges etc. A hotplug profile for a given74 class of devices is a collection of settings defining the way75 that class of devices will be handled by the ACPI core hotplug76 code. Those profiles are represented in sysfs as subdirectories77 of /sys/firmware/acpi/hotplug/.78 79 The following setting is available to user space for each80 hotplug profile:81 82 ======== =======================================================83 enabled: If set, the ACPI core will handle notifications of84 hotplug events associated with the given class of85 devices and will allow those devices to be ejected with86 the help of the _EJ0 control method. Unsetting it87 effectively disables hotplug for the corresponding88 class of devices.89 ======== =======================================================90 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 will93 cause -EINVAL to be returned.94 95What: /sys/firmware/acpi/interrupts/96Date: February 200897Contact: Len Brown <lenb@kernel.org>98Description:99 All ACPI interrupts are handled via a single IRQ,100 the System Control Interrupt (SCI), which appears101 as "acpi" in /proc/interrupts.102 103 However, one of the main functions of ACPI is to make104 the platform understand random hardware without105 special driver support. So while the SCI handles a few106 well known (fixed feature) interrupts sources, such107 as the power button, it can also handle a variable108 number of a "General Purpose Events" (GPE).109 110 A GPE vectors to a specified handler in AML, which111 can do a anything the BIOS writer wants from112 OS context. GPE 0x12, for example, would vector113 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 event116 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 listing121 every possible source, and the count of how many122 times it has triggered::123 124 $ cd /sys/firmware/acpi/interrupts125 $ grep . *126 error: 0127 ff_gbl_lock: 0 enable128 ff_pmtimer: 0 invalid129 ff_pwr_btn: 0 enable130 ff_rt_clk: 2 disable131 ff_slp_btn: 0 invalid132 gpe00: 0 invalid133 gpe01: 0 enable134 gpe02: 108 enable135 gpe03: 0 invalid136 gpe04: 0 invalid137 gpe05: 0 invalid138 gpe06: 0 enable139 gpe07: 0 enable140 gpe08: 0 invalid141 gpe09: 0 invalid142 gpe0A: 0 invalid143 gpe0B: 0 invalid144 gpe0C: 0 invalid145 gpe0D: 0 invalid146 gpe0E: 0 invalid147 gpe0F: 0 invalid148 gpe10: 0 invalid149 gpe11: 0 invalid150 gpe12: 0 invalid151 gpe13: 0 invalid152 gpe14: 0 invalid153 gpe15: 0 invalid154 gpe16: 0 invalid155 gpe17: 1084 enable156 gpe18: 0 enable157 gpe19: 0 invalid158 gpe1A: 0 invalid159 gpe1B: 0 invalid160 gpe1C: 0 invalid161 gpe1D: 0 invalid162 gpe1E: 0 invalid163 gpe1F: 0 invalid164 gpe_all: 1192165 sci: 1194166 sci_not: 0167 168 =========== ==================================================169 sci The number of times the ACPI SCI170 has been called and claimed an interrupt.171 172 sci_not The number of times the ACPI SCI173 has been called and NOT claimed an interrupt.174 175 gpe_all count of SCI caused by GPEs.176 177 gpeXX count for individual GPE source178 179 ff_gbl_lock Global Lock180 181 ff_pmtimer PM Timer182 183 ff_pwr_btn Power Button184 185 ff_rt_clk Real Time Clock186 187 ff_slp_btn Sleep Button188 189 error an interrupt that can't be accounted for above.190 191 invalid it's either a GPE or a Fixed Event that192 doesn't have an event handler.193 194 disable the GPE/Fixed Event is valid but disabled.195 196 enable the GPE/Fixed Event is valid and enabled.197 =========== ==================================================198 199 Root has permission to clear any of these counters. Eg.::200 201 # echo 0 > gpe11202 203 All counters can be cleared by clearing the total "sci"::204 205 # echo 0 > sci206 207 None of these counters has an effect on the function208 of the system, they are simply statistics.209 210 Besides this, user can also write specific strings to these files211 to enable/disable/clear ACPI interrupts in user space, which can be212 used to debug some ACPI interrupt storm issues.213 214 Note that only writing to VALID GPE/Fixed Event is allowed,215 i.e. user can only change the status of runtime GPE and216 Fixed Event with event handler installed.217 218 Let's take power button fixed event for example, please kill acpid219 and other user space applications so that the machine won't shutdown220 when pressing the power button::221 222 # cat ff_pwr_btn223 0 enabled224 # press the power button for 3 times;225 # cat ff_pwr_btn226 3 enabled227 # echo disable > ff_pwr_btn228 # cat ff_pwr_btn229 3 disabled230 # press the power button for 3 times;231 # cat ff_pwr_btn232 3 disabled233 # echo enable > ff_pwr_btn234 # cat ff_pwr_btn235 4 enabled236 /*237 * this is because the status bit is set even if the enable238 * bit is cleared, and it triggers an ACPI fixed event when239 * the enable bit is set again240 */241 # press the power button for 3 times;242 # cat ff_pwr_btn243 7 enabled244 # echo disable > ff_pwr_btn245 # press the power button for 3 times;246 # echo clear > ff_pwr_btn /* clear the status bit */247 # echo disable > ff_pwr_btn248 # cat ff_pwr_btn249 7 enabled250 251