正在尝试实现虚拟键盘。程序在 5 秒周期内发送击键事件。它在PC(Ubuntu Linux(上工作。问题是Beaglebone Black/Raspberry Pi3上没有显示任何内容。
Plaftorm Beaglebone Black， Debian Jessie：
debian@beaglebone:~$ uname -a
Linux beaglebone 4.9.9-ti-r22 #1 SMP PREEMPT Mon Feb 13 18:39:00 UTC 2017 armv7l GNU/Linux
法典：
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <linux/uinput.h>
/* emit function is identical to of the first example */
void emit(int fd, int type, int code, int val)
{
struct input_event ie;
ie.type = type;
ie.code = code;
ie.value = val;
/* timestamp values below are ignored */
ie.time.tv_sec = 0;
ie.time.tv_usec = 0;
int res = write(fd, &ie, sizeof(ie));
printf("emit write bytes=%d fd=%d code=%d val=%dn",res, fd, code, val);
}
int main(void)
{
struct uinput_user_dev uud;
int version, rc, fd;
fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
printf("fd=%dn",fd);
rc = ioctl(fd, UI_GET_VERSION, &version);
printf("rd=%dn",rc);
if (rc == 0 && version >= 5)
{
printf("Error! version=%dn",version);
//return 0;
}
/*
* The ioctls below will enable the device that is about to be
* created, to pass key events, in this case the space key.
*/
int i1 = ioctl(fd, UI_SET_EVBIT, EV_KEY);
int i2 = ioctl(fd, UI_SET_EVBIT, EV_SYN);
int i3 = ioctl(fd, UI_SET_KEYBIT, KEY_D);
int i4 = ioctl(fd, UI_SET_KEYBIT, KEY_U);
int i5 = ioctl(fd, UI_SET_KEYBIT, KEY_P);
int i6 = ioctl(fd, UI_SET_KEYBIT, KEY_A);
// printf("ioctl = %d, %d, %d ,%d , %d, %dn", i1,i2,i3,i4,i5,i6);
memset(&uud, 0, sizeof(uud));
snprintf(uud.name, UINPUT_MAX_NAME_SIZE, "uinput-keyboard");
uud.id.bustype = BUS_HOST;
uud.id.vendor = 0x1;
uud.id.product = 0x2;
uud.id.version = 1;
write(fd, &uud, sizeof(uud));
sleep(2);
int i = ioctl(fd, UI_DEV_CREATE);
printf("dev create =%dn", i);
sleep(2);
/* Key press, report the event, send key release, and report again */
for(;;)
{
emit(fd, EV_KEY, KEY_D, 1);
emit(fd, EV_SYN, SYN_REPORT, 1);
sleep(1);
emit(fd, EV_KEY, KEY_D, 0);
emit(fd, EV_SYN, SYN_REPORT, 0);
emit(fd, EV_KEY, KEY_U, 1);
emit(fd, EV_SYN, SYN_REPORT, 0);
emit(fd, EV_KEY, KEY_U, 0);
emit(fd, EV_SYN, SYN_REPORT, 0);
emit(fd, EV_KEY, KEY_P, 1);
emit(fd, EV_SYN, SYN_REPORT, 0);
emit(fd, EV_KEY, KEY_P, 0);
emit(fd, EV_SYN, SYN_REPORT, 0);
emit(fd, EV_KEY, KEY_A, 1);
emit(fd, EV_SYN, SYN_REPORT, 0);
emit(fd, EV_KEY, KEY_A, 0);
emit(fd, EV_SYN, SYN_REPORT, 0);
sleep(5);
}
ioctl(fd, UI_DEV_DESTROY);
close(fd);
return 0;
}
LSinput-EV位是否正确？ ：
/dev/input/event1
bustype : BUS_HOST
vendor : 0x1
product : 0x2
version : 1
name : "uinput-keyboard"
bits ev : (null) (null)
Evtest - 将事件发送到内核(其正常(：
root@beaglebone:/home/debian/KeyEvent# evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0: tps65217_pwr_but
/dev/input/event1: uinput-keyboard
Select the device event number [0-1]: 1
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x2 version 0x1
Input device name: "uinput-keyboard"
Supported events:
Event type 0 (EV_SYN)
Event type 1 (EV_KEY)
Event code 22 (KEY_U)
Event code 25 (KEY_P)
Event code 30 (KEY_A)
Event code 32 (KEY_D)
Properties:
Testing ... (interrupt to exit)
Event: time 1499869756.493690, type 1 (EV_KEY), code 32 (KEY_D), value 1
Event: time 1499869756.493690, -------------- SYN_REPORT ------------
Event: time 1499869757.494181, type 1 (EV_KEY), code 32 (KEY_D), value 0
Event: time 1499869757.494181, -------------- SYN_REPORT ------------
Event: time 1499869757.494304, type 1 (EV_KEY), code 22 (KEY_U), value 1
Event: time 1499869757.494304, -------------- SYN_REPORT ------------
Event: time 1499869757.494370, type 1 (EV_KEY), code 22 (KEY_U), value 0
Event: time 1499869757.494370, -------------- SYN_REPORT ------------
Event: time 1499869757.494434, type 1 (EV_KEY), code 25 (KEY_P), value 1
Event: time 1499869757.494434, -------------- SYN_REPORT ------------
Event: time 1499869757.494495, type 1 (EV_KEY), code 25 (KEY_P), value 0
Event: time 1499869757.494495, -------------- SYN_REPORT ------------
Event: time 1499869757.494558, type 1 (EV_KEY), code 30 (KEY_A), value 1
Event: time 1499869757.494558, -------------- SYN_REPORT ------------
Event: time 1499869757.499785, type 1 (EV_KEY), code 30 (KEY_A), value 0
Event: time 1499869757.499785, -------------- SYN_REPORT ------------
Event: time 1499869762.502378, type 1 (EV_KEY), code 32 (KEY_D), value 1
Event: time 1499869762.502378, -------------- SYN_REPORT ------------
Event: time 1499869763.225387, type 1 (EV_KEY), code 32 (KEY_D), value 0
Event: time 1499869763.225402, -------------- SYN_REPORT ------------
expected 16 bytes, got -1
我解决了这个问题。屏幕未连接到BeagleBone/Raspberry，系统无法将角色发送到屏幕。