rp2040

commit 5a718f4e0005fd215cf4362025175a187e26cdaa
parent cc23c47c55bfd937c7e30d0e01438e951e9e5e04
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Sun, 24 Aug 2025 07:30:57 +0900

add console programme

Diffstat:
A
cons/cons.c
 | 
130
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 130 insertions(+), 0 deletions(-)
diff --git a/cons/cons.c b/cons/cons.c
@@ -0,0 +1,130 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/termios.h>
+#include <unistd.h>
+
+int device_open();
+int setparms(int fd, int baud);
+int flush(int fd);
+
+#define ERRLEN 128
+char err[ERRLEN];
+
+int
+main(void)
+{
+	int fd;
+	int ret = 0;
+	struct termios *term;
+	
+	fd = device_open();
+	if (fd < 0) {
+		fprintf(stderr, "can't open device: %s\n", strerror(errno));
+		return 1;
+	}
+	if (setparms(fd, 115200) < 0) {
+		fprintf(stderr, "setparm: %s\n", err);
+		return 1;
+	}
+
+	if (flush(fd) < 0) {
+		fprintf(stderr, "flush: %s\n", strerror(errno));
+		ret = errno;
+		goto defer;
+	}
+
+	char buf[10];
+	int n;
+	for (;;) {
+		n = read(0, buf, 10);
+		if (n == 0) {
+			fprintf(stderr, "eof\n");
+			break;
+		} else if (n < 0) {
+			fprintf(stderr, "read stdin: %s\n", strerror(errno));
+			ret = errno;
+			goto defer;
+		}
+		n = write(fd, buf, n);
+		if (n < 0) {
+			fprintf(stderr, "write to tty %s\n", strerror(errno));
+			ret = errno;
+			goto defer;
+		}
+		n = read(fd, buf, 10);
+		if (n < 0) {
+			fprintf(stderr, "read tty: %s\n", strerror(errno));
+			ret = errno;
+			goto defer;
+		}
+		n = write(1, buf, n);
+		if (n < 0) {
+			fprintf(stderr, "write to stdout %s\n", strerror(errno));
+			ret = errno;
+			goto defer;
+		}
+	}
+
+defer:
+	close(fd);
+	return ret;
+}
+
+int
+device_open()
+{
+	int n;
+	int fd;
+
+	fd = open("/dev/ttyU0", O_RDWR|O_NDELAY|O_NOCTTY);
+	if (fd < 0)
+		return -1;
+	n = fcntl(fd, F_GETFL, 0);
+	fcntl(fd, F_SETFL, n&~O_NDELAY);
+	return fd;
+}
+
+int
+setparms(int fd, int baud)
+{
+	struct termios tty;
+	if (tcgetattr(fd, &tty) < 0) {
+		snprintf(err, ERRLEN, "tcgetattr: %s", strerror(errno));
+		return -1;
+	}
+	if (cfsetospeed(&tty, (speed_t)baud) < 0) {
+		snprintf(err, ERRLEN, "cfsetospeed: %s", strerror(errno));
+		return -1;
+	}
+	if (cfsetispeed(&tty, (speed_t)baud) < 0) {
+		snprintf(err, ERRLEN, "cfsetispeed: %s", strerror(errno));
+		return -1;
+	}
+	tty.c_cflag = (tty.c_cflag&~CSIZE) | CS8;
+	tty.c_iflag = IGNBRK;
+	tty.c_lflag = 0;
+	tty.c_oflag = 0;
+	tty.c_cflag |= CLOCAL|CREAD;
+	tty.c_cc[VMIN] = 1;
+	tty.c_cc[VTIME] = 5;
+	tty.c_iflag &= ~(IXON|IXOFF|IXANY); // TODO: xon, xoff?
+	// TODO: parity
+	tty.c_cflag &= ~CSTOPB; // stop bit == 1
+	if (tcsetattr(fd, TCSANOW, &tty) < 0) {
+		snprintf(err, ERRLEN, "tcseattr: %s", strerror(errno));
+		return -1;
+	}
+	// TODO: rs485
+	return 0;
+}
+
+int
+flush(int fd)
+{
+	int out = 0;
+	return ioctl(fd, TIOCFLUSH, &out);
+}