Commit | Line | Data |
---|---|---|
d1ff4b1c MG |
1 | What: /sys/firmware/acpi/bgrt/ |
2 | Date: January 2012 | |
3 | Contact: Matthew Garrett <mjg@redhat.com> | |
4 | Description: | |
5 | The BGRT is an ACPI 5.0 feature that allows the OS | |
6 | to obtain a copy of the firmware boot splash and | |
7 | some associated metadata. This is intended to be used | |
8 | by boot splash applications in order to interact with | |
9 | the firmware boot splash in order to avoid jarring | |
10 | transitions. | |
11 | ||
12 | image: The image bitmap. Currently a 32-bit BMP. | |
13 | status: 1 if the image is valid, 0 if firmware invalidated it. | |
14 | type: 0 indicates image is in BMP format. | |
15 | version: The version of the BGRT. Currently 1. | |
16 | xoffset: The number of pixels between the left of the screen | |
17 | and the left edge of the image. | |
18 | yoffset: The number of pixels between the top of the screen | |
19 | and the top edge of the image. | |
20 | ||
5229e87d LB |
21 | What: /sys/firmware/acpi/interrupts/ |
22 | Date: February 2008 | |
23 | Contact: Len Brown <lenb@kernel.org> | |
24 | Description: | |
25 | All ACPI interrupts are handled via a single IRQ, | |
26 | the System Control Interrupt (SCI), which appears | |
27 | as "acpi" in /proc/interrupts. | |
28 | ||
29 | However, one of the main functions of ACPI is to make | |
30 | the platform understand random hardware without | |
31 | special driver support. So while the SCI handles a few | |
32 | well known (fixed feature) interrupts sources, such | |
33 | as the power button, it can also handle a variable | |
34 | number of a "General Purpose Events" (GPE). | |
35 | ||
36 | A GPE vectors to a specified handler in AML, which | |
37 | can do a anything the BIOS writer wants from | |
38 | OS context. GPE 0x12, for example, would vector | |
39 | to a level or edge handler called _L12 or _E12. | |
40 | The handler may do its business and return. | |
41 | Or the handler may send send a Notify event | |
42 | to a Linux device driver registered on an ACPI device, | |
43 | such as a battery, or a processor. | |
44 | ||
45 | To figure out where all the SCI's are coming from, | |
46 | /sys/firmware/acpi/interrupts contains a file listing | |
47 | every possible source, and the count of how many | |
48 | times it has triggered. | |
49 | ||
50 | $ cd /sys/firmware/acpi/interrupts | |
51 | $ grep . * | |
71b58cbb ZR |
52 | error: 0 |
53 | ff_gbl_lock: 0 enable | |
54 | ff_pmtimer: 0 invalid | |
55 | ff_pwr_btn: 0 enable | |
56 | ff_rt_clk: 2 disable | |
57 | ff_slp_btn: 0 invalid | |
58 | gpe00: 0 invalid | |
59 | gpe01: 0 enable | |
60 | gpe02: 108 enable | |
61 | gpe03: 0 invalid | |
62 | gpe04: 0 invalid | |
63 | gpe05: 0 invalid | |
64 | gpe06: 0 enable | |
65 | gpe07: 0 enable | |
66 | gpe08: 0 invalid | |
67 | gpe09: 0 invalid | |
68 | gpe0A: 0 invalid | |
69 | gpe0B: 0 invalid | |
70 | gpe0C: 0 invalid | |
71 | gpe0D: 0 invalid | |
72 | gpe0E: 0 invalid | |
73 | gpe0F: 0 invalid | |
74 | gpe10: 0 invalid | |
75 | gpe11: 0 invalid | |
76 | gpe12: 0 invalid | |
77 | gpe13: 0 invalid | |
78 | gpe14: 0 invalid | |
79 | gpe15: 0 invalid | |
80 | gpe16: 0 invalid | |
81 | gpe17: 1084 enable | |
82 | gpe18: 0 enable | |
83 | gpe19: 0 invalid | |
84 | gpe1A: 0 invalid | |
85 | gpe1B: 0 invalid | |
86 | gpe1C: 0 invalid | |
87 | gpe1D: 0 invalid | |
88 | gpe1E: 0 invalid | |
89 | gpe1F: 0 invalid | |
90 | gpe_all: 1192 | |
91 | sci: 1194 | |
88bea188 | 92 | sci_not: 0 |
5229e87d | 93 | |
88bea188 LB |
94 | sci - The number of times the ACPI SCI |
95 | has been called and claimed an interrupt. | |
96 | ||
97 | sci_not - The number of times the ACPI SCI | |
98 | has been called and NOT claimed an interrupt. | |
5229e87d LB |
99 | |
100 | gpe_all - count of SCI caused by GPEs. | |
101 | ||
102 | gpeXX - count for individual GPE source | |
103 | ||
104 | ff_gbl_lock - Global Lock | |
105 | ||
106 | ff_pmtimer - PM Timer | |
107 | ||
108 | ff_pwr_btn - Power Button | |
109 | ||
110 | ff_rt_clk - Real Time Clock | |
111 | ||
112 | ff_slp_btn - Sleep Button | |
113 | ||
114 | error - an interrupt that can't be accounted for above. | |
115 | ||
ed206fac | 116 | invalid: it's either a GPE or a Fixed Event that |
71b58cbb ZR |
117 | doesn't have an event handler. |
118 | ||
119 | disable: the GPE/Fixed Event is valid but disabled. | |
120 | ||
121 | enable: the GPE/Fixed Event is valid and enabled. | |
122 | ||
5229e87d LB |
123 | Root has permission to clear any of these counters. Eg. |
124 | # echo 0 > gpe11 | |
125 | ||
126 | All counters can be cleared by clearing the total "sci": | |
127 | # echo 0 > sci | |
128 | ||
129 | None of these counters has an effect on the function | |
130 | of the system, they are simply statistics. | |
71b58cbb ZR |
131 | |
132 | Besides this, user can also write specific strings to these files | |
133 | to enable/disable/clear ACPI interrupts in user space, which can be | |
134 | used to debug some ACPI interrupt storm issues. | |
135 | ||
136 | Note that only writting to VALID GPE/Fixed Event is allowed, | |
137 | i.e. user can only change the status of runtime GPE and | |
138 | Fixed Event with event handler installed. | |
139 | ||
140 | Let's take power button fixed event for example, please kill acpid | |
141 | and other user space applications so that the machine won't shutdown | |
142 | when pressing the power button. | |
143 | # cat ff_pwr_btn | |
ed206fac | 144 | 0 enabled |
71b58cbb ZR |
145 | # press the power button for 3 times; |
146 | # cat ff_pwr_btn | |
ed206fac | 147 | 3 enabled |
71b58cbb ZR |
148 | # echo disable > ff_pwr_btn |
149 | # cat ff_pwr_btn | |
ed206fac | 150 | 3 disabled |
71b58cbb ZR |
151 | # press the power button for 3 times; |
152 | # cat ff_pwr_btn | |
ed206fac | 153 | 3 disabled |
71b58cbb ZR |
154 | # echo enable > ff_pwr_btn |
155 | # cat ff_pwr_btn | |
ed206fac | 156 | 4 enabled |
71b58cbb ZR |
157 | /* |
158 | * this is because the status bit is set even if the enable bit is cleared, | |
159 | * and it triggers an ACPI fixed event when the enable bit is set again | |
160 | */ | |
161 | # press the power button for 3 times; | |
162 | # cat ff_pwr_btn | |
ed206fac | 163 | 7 enabled |
71b58cbb ZR |
164 | # echo disable > ff_pwr_btn |
165 | # press the power button for 3 times; | |
166 | # echo clear > ff_pwr_btn /* clear the status bit */ | |
167 | # echo disable > ff_pwr_btn | |
168 | # cat ff_pwr_btn | |
ed206fac | 169 | 7 enabled |
71b58cbb | 170 |