bmc
尝试分析一下 bmc 中使用键盘鼠标的整个 io 路径
i8042 在硬中断里面:
kbd_event+5
input_handle_events_default+66
input_pass_values+307
input_event_dispose+322
input_event+78
atkbd_receive_byte+1350
ps2_interrupt+158
serio_interrupt+71
i8042_handle_data+247
i8042_interrupt+17
__handle_irq_event_percpu+74
handle_irq_event+59
handle_edge_irq+151
__common_interrupt+62
common_interrupt+128
asm_common_interrupt+38
pv_native_safe_halt+15
default_idle+19
default_idle_call+48
do_idle+437
cpu_startup_entry+41
start_secondary+247
common_startup_64+318
但是 usb 在软中断里面在软中断里面:
@[
show_state_filter+0
k_spec+112
kbd_keycode.constprop.0+856
kbd_event+308
input_handle_events_default+96
input_pass_values+288
input_event_dispose+312
input_handle_event+88
input_event+104
hidinput_report_event+72
hid_report_raw_event+164
__hid_input_report.constprop.0+284
hid_input_report+24
hid_irq_in+584
__usb_hcd_giveback_urb+160
usb_giveback_urb_bh+240
process_one_work+376
bh_worker+552
workqueue_softirq_action+128
tasklet_hi_action+28
handle_softirqs+300
__do_softirq+28
____do_softirq+24
call_on_irq_stack+36
do_softirq_own_stack+36
__irq_exit_rcu+316
irq_exit_rcu+24
el1_interrupt+72
el1h_64_irq_handler+24
el1h_64_irq+128
default_idle_call+56
cpuidle_idle_call+380
do_idle+244
cpu_startup_entry+64
secondary_start_kernel+224
__secondary_switched+192
]: 1
code: 4, type: 4, value: 458889 code: 124, type: 1, value: 1 code: 0, type: 0, value: 0 code: 4, type: 4, value: 458889 code: 124, type: 1, value: 0 code: 0, type: 0, value: 0
// 进入到 kspec 中
(*k_handler[type])(vc, keysym & 0xff, !down);
这里 type = 2 ，keysym & 0xff = 4
解释这个问题:
sudo bpftrace -e 'fentry:kbd_event { printf("code: %d, type: %d, value: %d\n", args->event_code, args->event_type, args->value); }'
正常的机器上按 f
code: 4, type: 4, value: 33
code: 33, type: 1, value: 1
code: 0, type: 0, value: 0
code: 4, type: 4, value: 33
code: 33, type: 1, value: 0
code: 0, type: 0, value: 0
按下 F 键： type: 4, code: 4, value: 33：硬件报告扫描码 33（F 键）。 type: 1, code: 33, value: 1：输入子系统记录按下 F 键。 释放 F 键： type: 4, code: 4, value: 33：硬件报告扫描码 33（可能表示释放）。 type: 1, code: 33, value: 0：输入子系统记录释放 F 键。
code 解码: include/uapi/linux/input-event-codes.h
code: 4, type: 4, value: 458889
code: 124, type: 1, value: 1
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458889
code: 124, type: 1, value: 0
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458976
code: 29, type: 1, value: 1
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458774
code: 31, type: 1, value: 1
code: 0, type: 0, value: 0
code: 2, type: 17, value: 1
(Scroll Lock LED 打开，可能由系统或键盘驱动触发。)
code: 4, type: 4, value: 458774
code: 31, type: 1, value: 0
code: 0, type: 0, value: 0
(S)
code: 4, type: 4, value: 458976
code: 29, type: 1, value: 0
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458976
code: 29, type: 1, value: 1
code: 4, type: 4, value: 458823
code: 70, type: 1, value: 1
(释放 Scroll Lock)
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458823
code: 70, type: 1, value: 0
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458976
code: 29, type: 1, value: 0
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458774
code: 31, type: 1, value: 1
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458774
code: 31, type: 1, value: 0
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458823
code: 70, type: 1, value: 1
code: 0, type: 0, value: 0
code: 2, type: 17, value: 0
code: 4, type: 4, value: 458823
code: 70, type: 1, value: 0
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458976
code: 29, type: 1, value: 1
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458983
code: 126, type: 1, value: 1
code: 0, type: 0, value: 0
code: 4, type: 4, value: 458976
code: 29, type: 1, value: 0
code: 4, type: 4, value: 458983
code: 126, type: 1, value: 0
code: 0, type: 0, value: 0
qemu 中运行 bmc
https://jia.je/system/2023/08/11/openbmc-qemu/#ast2600
bmc 和 ipmi 是什么关系
他们的用户态程序都是什么?
相当于物理机上还有一个 ipmi 的设备
当然，这个日志现在是虚拟机中观察到的:
[ 2.748021][ T792] ipmi_si: IPMI System Interface driver
[ 2.748798][ T792] ipmi_si dmi-ipmi-si.0: ipmi_platform: probing via SMBIOS
[ 2.749385][ T792] ipmi_platform: ipmi_si: SMBIOS: io 0x0 regsize 1 spacing 1 irq 0
[ 2.750255][ T792] ipmi_si: Adding SMBIOS-specified kcs state machine
[ 2.750915][ T792] ipmi_si 0000:00:0a.0: probing via PCI
[ 2.752672][ T792] ipmi_si 0000:00:0a.0: [io 0xc390-0xc397] regsize 1 spacing 1 irq 10
[ 2.753529][ T792] ipmi_si: Adding PCI-specified kcs state machine
[ 2.754177][ T792] ipmi_si: Trying PCI-specified kcs state machine at i/o address 0xc390, slave address 0x0, irq 10
[ 2.755492][ T792] ipmi_si 0000:00:0a.0: Using irq 10
[ 2.766942][ T792] ipmi_si 0000:00:0a.0: IPMI message handler: Found new BMC (man_id: 0x000000, prod_id: 0x0000, dev_id: 0x20)
[ 2.771969][ T792] ipmi_si 0000:00:0a.0: IPMI kcs interface initialized
本站所有文章转发 CSDN 将按侵权追究法律责任，其它情况随意。