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 44What: /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. 58 59 ======== =================================================== 60 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. 65 ======== =================================================== 66 67What: /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 82 ======== ======================================================= 83 enabled: If set, the ACPI core will handle notifications of 84 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 corresponding 88 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 will 93 cause -EINVAL to be returned. 94 95What: /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 122 times it has triggered:: 123 124 $ cd /sys/firmware/acpi/interrupts 125 $ grep . * 126 error: 0 127 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 132 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 164 gpe_all: 1192 165 sci: 1194 166 sci_not: 0 167 168 =========== ================================================== 169 sci The number of times the ACPI SCI 170 has been called and claimed an interrupt. 171 172 sci_not The number of times the ACPI SCI 173 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 source 178 179 ff_gbl_lock Global Lock 180 181 ff_pmtimer PM Timer 182 183 ff_pwr_btn Power Button 184 185 ff_rt_clk Real Time Clock 186 187 ff_slp_btn Sleep Button 188 189 error an interrupt that can't be accounted for above. 190 191 invalid it's either a GPE or a Fixed Event that 192 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 > gpe11 202 203 All counters can be cleared by clearing the total "sci":: 204 205 # echo 0 > sci 206 207 None of these counters has an effect on the function 208 of the system, they are simply statistics. 209 210 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. 213 214 Note that only writing to VALID GPE/Fixed Event is allowed, 215 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 220 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 250 251