WhyCan Forum(哇酷开发者社区)

俺长期从事linux内核和bsp开发，2021年一直口水D1哪吒开发板不过一直没舍得买，这次买了Lichee_RV_DOCK。开箱图就不贴了，烧Tina系统的img，用usb串口转接连EXTIO的GND、TX、RX引脚，串口可获得shell。下面做些官方wiki中https://wiki.sipeed.com/hardware/zh/lichee/RV/RV.html没有的小实验：

1.用户按键
在hdmi口边上下有两个键，一是RST，另一个即user按键

root@MaixLinux:/mnt/SDCARD# ./evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0:      sunxi-keyboard
/dev/input/event1:      audiocodec sunxi Audio Jack
/dev/input/event2:      fts_ts
Select the device event number [0-2]: 0
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "sunxi-keyboard"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 28 (KEY_ENTER)
    Event code 114 (KEY_VOLUMEDOWN)
    Event code 139 (KEY_MENU)
    Event code 172 (KEY_HOMEPAGE)
    Event code 352 (KEY_OK)
Properties:
Testing ... (interrupt to exit)
Event: time 6994.130779, type 1 (EV_KEY), code 352 (KEY_OK), value 1
Event: time 6994.130779, -------------- SYN_REPORT ------------
Event: time 6994.219394, type 1 (EV_KEY), code 352 (KEY_OK), value 0
Event: time 6994.219394, -------------- SYN_REPORT ------------

所以此用户按键默认键码是KEY_OK

2. rtc

root@MaixLinux:~# cat /sys/class/rtc/rtc0/time && sleep 10 && cat /sys/class/rtc/rtc0/time
01:58:24
01:58:33
root@MaixLinux:/mnt/SDCARD# ./rtctest

                        RTC Driver Test Example.

Counting 5 update (1/sec) interrupts from reading /dev/rtc0: 1 2 3 4 5
Again, from using select(2) on /dev/rtc: 1 2 3 4 5

Current RTC date/time is 1-1-1970, 01:52:04.
Alarm time now set to 01:52:09.
Waiting 5 seconds for alarm... okay. Alarm rang.

                         *** Test complete ***

3.watchdog
因watchdog被procd进程占用，故暂未测试wdt的功能，等用buildroot构建一个简单系统后可测

4.芯片里的温度sensor

root@MaixLinux:~# cat /sys/class/thermal/thermal_zone0/temp
30820

单位按linux惯例应该是毫摄氏度，所以这里报告温度是30.82度

5. sdcard和sdio的一些基本参数

root@MaixLinux:~# cat /sys/kernel/debug/mmc0/ios
clock:          50000000 Hz
vdd:            21 (3.3 ~ 3.4 V)
bus mode:       2 (push-pull)
chip select:    0 (don't care)
power mode:     2 (on)
bus width:      2 (4 bits)
timing spec:    2 (sd high-speed)
signal voltage: 0 (3.30 V)
driver type:    0 (driver type B)
root@MaixLinux:~# cat /sys/kernel/debug/mmc1/ios
clock:          50000000 Hz
vdd:            21 (3.3 ~ 3.4 V)
bus mode:       2 (push-pull)
chip select:    0 (don't care)
power mode:     2 (on)
bus width:      2 (4 bits)
timing spec:    2 (sd high-speed)
signal voltage: 0 (3.30 V)
driver type:    0 (driver type B)

所以sdcard也好，用于wifi的sdio也好，都是HS模式，时钟最高到50MHZ，工作电压3.3V，sd总线4位宽。

6. 各clock/pll基本情况

root@MaixLinux:~# cat /sys/kernel/debug/clk/clk_summary
...
    pll-ddr0                          2        2        0  1584000000          0     0  50
000
       dram-clk                       0        0        0  1584000000          0     0  50
000
...
    pll-cpux                          0        0        0  1008000000          0     0  50
000
       riscv                          0        0        0  1008000000          0     0  50
000
          riscv-axi                   0        0        0   504000000          0     0  50
000
       pll-cpux-div                   0        0        0  1008000000          0     0  50
000
...

这个列表好长，只把感兴趣的部分贴出。这表明那颗riscv cpu跑在1008MHZ频率下，DDR基础频率1584MHZ

注：evtest和rtctest是自己编译的程序，系统未自带。